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02_SR&R_Crowatan_Lot_E&SC_Plan_30Apr2024_v1 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 4/30/2024 4/30/2024 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Erosion and Sedimentation Control Plan October 2023 (Revised April 2024) Page 1 1.0 NARRATIVE 1.1 Project Description Smith Gardner, Inc. (S+G) is assisting SR&R Environmental, Inc. (SR&R) and Techwood Crowatan, LLC with preparing an Erosion and Sedimentation Control Plan for their site located at 220 Crowatan Road in Castle Hayne, North Carolina 28429 (deed attached). SR&R Environmental, Inc. plans to use this site for a laydown yard and storage facility for their equipment as they have outgrown their other facilities. This project consists of rerouting offsite stormwater run-on flow through a 15” culvert through the middle of the property, to an open channel ditch directed toward the eastern property line. The installation of a gravel laydown yard approximately 3.0 acres in size, as well as the installation of a sediment basin to manage stormwater runoff. The sediment basin was designed with the assumption that groundwater elevations were less than or equal to 25’ Mean Sea Level (MSL). 1.2 Site Location The attached USGS map (Castle Hayne Quadrangle) shows the approximate location of the site for this project. Additional information is as follows: Address: 220 Crowatan Road Castle Hayne, NC 28429 Deed Information: Book 6573, Pages 881-884 Coordinates (Site Entrance): Latitude: 34.33 degrees Longitude: -77.91 degrees River Basin: Cape Fear Receiving Stream(s) (Stream Classification): Northeast Cape Fear River (C; SW) 1.3 Contact Information 1.3.1 Engineer For questions regarding this erosion and sedimentation control plan, please contact the following: Smith Gardner, Inc. Attn.: Stacey A. Smith, P.E. 14 N. Boylan Ave. Raleigh, NC 27603 Phone: (919) 828-0577 Email: stacey@smithgardnerinc.com. DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Erosion and Sedimentation Control Plan October 2023 (Revised April 2024) Page 2 1.3.2 Owner The owner of the site and the person to contact should sediment control issues arise during the land-disturbing activity is as follows: Techwood Crowatan, LLC P.O. Box 1152 Wilmington, NC 28402 Phone: (910) 622-3933 Contact: William W. Murrell III wmurrell@srrenviro.com 1.4 Existing Site Conditions Existing conditions primarily consist of an empty, grassed lot, with three piles of stumps and trees from where the lot was previously cleared. A 15-inch drainage pipe runs through the center of the property from south to north, replacing an open ditch that was to remain per the New Hanover County Storm Water Ordinance1. The property slopes gently to drainage channels on the western and eastern property lines. There currently are no buildings on this parcel. There is a 50’ drainage easement on the western property line, along with a 10’ Utility easement on the eastern property line. Drawing S1 of Appendix D shows the Existing Conditions. 1.5 Adjacent Areas The proposed project area is adjacent to privately owned property to the north, south, and west with a drainage channel on the western property line. Crowatan Road borders the property to the east. Approximately 8.7-acres south of the property drain onsite via an open channel to a 15-inch pipe that runs through the center of the property. The proposed drainage channel redirects the offsite run-on along the southern property line to the east, to an open channel along Crowatan Road. The offsite run-on drainage area is assumed to be a predominately flat, wooded area, with similar sandy soil as the project area. Based on these assumptions, and runoff calculations for the drainage area, found in Appendix B, the designed channel will adequately handle the required 25- year 24-hour storm. 1 Map of Minor Subdivision for Garry D. Silivanch and wife, Bernadette Silivanch dated March 22, 2018, New Hanover County Register of Deeds, Map Book 64, Page 211 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 • • DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 • • • • DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Site Location DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Site Location DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Site Location DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Site Location DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 53.3 Acres Site Location DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8 DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 9 Custom Soil Resource Report Soil Map 38 0 2 1 0 0 38 0 2 1 8 0 38 0 2 2 6 0 38 0 2 3 4 0 38 0 2 4 2 0 38 0 2 5 0 0 38 0 2 0 2 0 38 0 2 1 0 0 38 0 2 1 8 0 38 0 2 2 6 0 38 0 2 3 4 0 38 0 2 4 2 0 38 0 2 5 0 0 232020 232100 232180 232260 232340 232420 232500 232580 232660 232740 232020 232100 232180 232260 232340 232420 232500 232580 232660 232740 34° 19' 45'' N 77 ° 5 4 ' 4 6 ' ' W 34° 19' 45'' N 77 ° 5 4 ' 1 6 ' ' W 34° 19' 30'' N 77 ° 5 4 ' 4 6 ' ' W 34° 19' 30'' N 77 ° 5 4 ' 1 6 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 150 300 600 900Feet 0 50 100 200 300Meters Map Scale: 1:3,410 if printed on A landscape (11" x 8.5") sheet. Soil Map may not be valid at this scale. FIGURE 9DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 • • • • • • • • • • • • • • • • • • DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 ADDRESS TEL WEB PROJECT SHEET 1 OF 2 DATE COMPUTED BY SUBJECT JOB #CHECKED BY OBJECTIVE: ••Peak discharge calculations using the Rational Method and/or USDA-NRCS (SCS) Methods; and •Stormwater routing using USDA-NRCS (SCS) or other methods. REFERENCES: ANALYSIS: CALCULATIONS: - Peak Discharge Calculations: USDA-NRCS (SCS) Methods: LJK Drainage & E&SC Calcs. - Overview SR&R 23-1 JCL To design stormwater conveyance, detention, and erosion and sedimentation control measures to remove and contain stormwater flow from the design storm. The design of these measures will be based on: Design storm information for the site; Debo, T.N., and Reese, A.J. (1995), Municipal Storm Water Management, Lewis Publishers, Boca Raton, FL. 14 N. Boylan Avenue, Raleigh, NC 27603 919.828.0577 www.smithgardnerinc.com SR&R Environmental, Inc.8/29/2023 Federal Highway Administration (2001), Urban Drainage Design Manual, Hydraulic Engineering Circular No. 22, FHWA NHI-01-021, Second Ed., U.S. Dept. of Transportation, Washington, D.C. Georgia Soil and Water Conservation Commission (2000), Manual for Erosion and Sediment Control in Georgia, Fifth Edition, Athens, GA. HydroCAD Software Solutions, LLC (2006), HydroCAD Stormwater Modeling System Owner’s Manual - Version 8, Chocorua, NH. Malcom, H. Rooney (1989 & 2003 Supplement), Elements of Urban Stormwater Design, NC State Univ., Raleigh, NC. North Carolina Division of Land Resources (2013 Updates), North Carolina Erosion & Sediment Control Planning & Design Manual, Raleigh, NC. North Carolina Division of Water Quality (July 2005) Updated Draft Manual of Stormwater Best Management Practices, (Public Comment Version), Raleigh, NC. Use HydroCAD program to determine the peak discharge to each device or structure. HydroCAD is based on the SCS unit hydrograph procedure, which is a principal component of NRCS TR-20. Alternatively spreadsheets can be used to determine flow rates using the procedures detailed in NRCS TR-55. Pennsylvania DEP Bureau of Watershed Protection (2000), Erosion and Sediment Pollution Control Program Manual. USDA-NRCS (1992), Computer Program for Project Formulation Hydrology (TR-20). USDA-NRCS (1986 & 1999 Update), Urban Hydrology for Small Watersheds (TR-55). Virginia Department of Conservation and Recreation (1992), Virginia Erosion & Sediment Control Handbook, Third Edition, Richmond, VA. The main design criteria will be to ensure that all stormwater conveyance and detention measures will be able to accommodate the runoff from the design storm. Drainage channels, culverts, etc. were designed based on the peak discharge to each measure. Detention measures were designed based on stormwater routing methods and/or State/local criteria. SMITH GARDNER, INC.01 SRR D&E&SC OVERVIEW SG DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEET 2 OF 2 DATE COMPUTED BY SUBJECT JOB #CHECKED BY Rational Method: Q = CIA (Malcom Eq. I -1) where:Q = peak discharge (cfs) C =rational runoff coefficient I =applicable rainfall intensity (in/hr) of storm event (based on time of concentration) A =drainage area (acres) Time of Concentration: - Stormwater Routing: SR&R 23-1 JCL SR&R Environmental, Inc.8/29/2023 Stormwater routing was accomplished using the HydroCAD program, which is based on USDA-NRCS (SCS) methods. Unless otherwise specified, the unit hydrograph method was used. The storm type (i.e. Type I 24-hr., Type II 24-hr., etc.) was selected as appropriate for the project location. The time of concentration for use in determining the peak discharge in the NRCS and/or Rational methods can be determined by the methods detailed in NRCS TR-55 or other methods. HydroCAD uses the NRCS methods. LJK Drainage & E&SC Calcs. - Overview SMITH GARDNER, INC.01 SRR D&E&SC OVERVIEW SG DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 ADDRESS TEL WEB PROJECT SHEET 1 OF 2 DATECOMPUTED BYSUBJECTJOB #CHECKED BY OBJECTIVE: REFERENCES: SR&R 23-1 JCL Rainfall data was obtained from the following references: US Department of Commerce, NOAA (2017, April 17). NOAA Atlas 14 Point Precipitation Frequency Estimates: NC. Hydrometeorological Design Studies Center, Precipitation Frequency Data Server (PFDS). https://hdsc.nws.noaa.gov/pfds/pfds_map_cont.html?bkmrk=nc 14 N. Boylan Avenue, Raleigh, NC 27603 919.828.0577 www.smithgardnerinc.com SR&R Environmental, Inc.1/31/2024 To compile the expected design storm depths and intensities over various return periods. These design storm values will be used in various calculations. LJKAnalysis of Design Storms SMITH GARDNER, INC.02 SRR DESIGN STORMS SG DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYCHECKED BY LOCATION: 2-YR P 100-YR P SOURCE(in)(in) 0.62 1.061.24 2.142.14 4.51 DEPTH-DURATION-FREQUENCY TABLE: 2-YR 5-YR 10-YR 25-YR 50-YR 100-YR(in)(in)(in)(in)(in)(in) 0.62 0.71 0.78 0.89 0.98 1.060.98 1.14 1.25 1.42 1.56 1.701.24 1.43 1.58 1.79 1.97 2.141.68 2.05 2.32 2.70 3.00 3.302.14 2.70 3.09 3.64 4.08 4.512.56 3.26 3.84 4.69 5.41 6.202.73 3.50 4.16 5.14 6.00 6.953.38 4.33 5.16 6.40 7.48 8.703.96 5.11 6.12 7.64 9.00 10.504.62 5.98 7.17 9.01 10.70 12.50 INTENSITY-DURATION-FREQUENCY TABLE: 2-YR 5-YR 10-YR 25-YR 50-YR 100-YR(in/hr)(in/hr)(in/hr)(in/hr)(in/hr)(in/hr) 7.39 8.52 9.38 10.68 11.70 12.725.90 6.81 7.50 8.54 9.37 10.184.96 5.72 6.30 7.18 7.87 8.563.36 4.10 4.63 5.40 6.00 6.602.14 2.70 3.09 3.64 4.08 4.511.28 1.63 1.92 2.35 2.71 3.100.91 1.17 1.39 1.71 2.00 2.320.56 0.72 0.86 1.07 1.25 1.450.33 0.43 0.51 0.64 0.75 0.880.19 0.25 0.30 0.38 0.45 0.52 JCL 2/2SR&R 23-11/31/2024LJK SR&R Environmental, Inc. Analysis of Design Storms 15 min5 min 60 min 10 min15 min NOAA ATLAS 14NOAA ATLAS 14NOAA ATLAS 14 Castle Hayne, NC RETURN PERIOD 30 min 12 hr24 hr RETURN PERIOD 30 min60 min RETURN PERIOD DURATION 6 hr 2 hr3 hr DURATION 5 min 12 hr24 hr DURATION 60 min2 hr3 hr6 hr 5 min10 min15 min SMITH GARDNER, INC.02 SRR DESIGN STORMS SG DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DOT DA NCDOT R/W Ditch Drainage Area (Off-Site) Easement Off-Site Drainage JD DA Off-Site Drainage Lot Crowatan Lot On Site Drainage WDE DA On-Site Drainage DOT-1 NCDOT R/W Ditch JD Jurisdictional Ditch WDE West Drainage Easement Ditch C-1CB Driveway Pipe Drainage Diagram for SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcat Reach Pond Link Pre-Construction Conditions DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 2Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres)CN Description (subcats) 47.500 77 Woods, Good, HSG D (DOT DA,Easement,JD DA) 6.900 80 >75% Grass cover, Good, HSG D (Easement) 9.400 89 <50% Grass cover, Poor, HSG D (DOT DA,Lot,WDE DA) 0.900 89 Dirt roads, HSG D (Easement) 0.900 98 Paved parking & roofs (DOT DA,Easement,JD DA) 65.600 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 3Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=13.200 ac Runoff Depth=2.83"Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Of Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 Runoff=7.58 cfs 3.116 af Runoff Area=42.500 ac Runoff Depth=2.39"Subcatchment Easement: Off-Site Drainage Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 Runoff=15.06 cfs 8.473 af Runoff Area=6.500 ac Runoff Depth=2.31"Subcatchment JD DA: Off-Site Drainage Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 Runoff=4.46 cfs 1.250 af Runoff Area=2.200 ac Runoff Depth>3.41"Subcatchment Lot: Crowatan Lot On Site Drainage Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=89 Runoff=6.34 cfs 0.625 af Runoff Area=1.200 ac Runoff Depth>3.41"Subcatchment WDE DA: On-Site Drainage Tc=5.0 min CN=89 Runoff=4.71 cfs 0.341 af Avg. Depth=0.91' Max Vel=1.69 fps Inflow=7.58 cfs 3.116 afReach DOT-1: NCDOT R/W Ditch n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs Outflow=7.58 cfs 3.116 af Avg. Depth=0.84' Max Vel=1.04 fps Inflow=6.99 cfs 1.875 afReach JD: Jurisdictional Ditch n=0.030 L=260.0' S=0.0008 '/' Capacity=33.37 cfs Outflow=6.65 cfs 1.875 af Avg. Depth=2.32' Max Vel=0.64 fps Inflow=15.20 cfs 8.814 afReach WDE: West Drainage Easement Ditch n=0.200 L=260.0' S=0.0038 '/' Capacity=11.88 cfs Outflow=15.15 cfs 8.814 af Peak Elev=28.09' Inflow=7.58 cfs 3.116 afPond C-1: Driveway Pipe 15.0" x 84.0' Culvert Outflow=7.58 cfs 3.116 af Total Runoff Area = 65.600 ac Runoff Volume = 13.805 af Average Runoff Depth = 2.53" 98.63% Pervious Area = 64.700 ac 1.37% Impervious Area = 0.900 ac DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 4Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Off-Site) Runoff =7.58 cfs @ 14.55 hrs, Volume=3.116 af, Depth= 2.83" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR, 24-HR Rainfall=4.62" Area (ac) CN Description 6.600 77 Woods, Good, HSG D 0.600 98 Paved parking & roofs 6.000 89 <50% Grass cover, Poor, HSG D 13.200 83 Weighted Average 12.600 Pervious Area 0.600 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, Dense woods n= 0.200 P2= 4.62" 31.6 150 0.0010 0.08 Shallow Concentrated Flow, Dense woods Forest w/Heavy Litter Kv= 2.5 fps 135.0 2,200 0.0010 0.27 3.26 Trap/Vee/Rect Channel Flow, Channel Bot.W=4.00' D=2.00' Z= 1.0 '/' Top.W=8.00' n= 0.200 200.6 2,450 Total Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Off-Site) Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 8 7 6 5 4 3 2 1 0 Type III 24-hr 2-YR 24-HR Rainfall=4.62" Runoff Area=13.200 ac Runoff Volume=3.116 af Runoff Depth=2.83" Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 7.58 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 5Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Easement: Off-Site Drainage Runoff =15.06 cfs @ 16.07 hrs, Volume=8.473 af, Depth= 2.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR, 24-HR Rainfall=4.62" Area (ac) CN Description 34.500 77 Woods, Good, HSG D 0.900 89 Dirt roads, HSG D 6.900 80 >75% Grass cover, Good, HSG D 0.200 98 Paved parking & roofs 42.500 78 Weighted Average 42.300 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 42.2 200 0.0010 0.08 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 231.0 4,200 0.0010 0.30 6.06 Trap/Vee/Rect Channel Flow, Bot.W=8.00' D=2.00' Z= 1.0 '/' Top.W=12.00' n= 0.200 307.2 4,500 Total Subcatchment Easement: Off-Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 2-YR 24-HR Rainfall=4.62" Runoff Area=42.500 ac Runoff Volume=8.473 af Runoff Depth=2.39" Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 15.06 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 6Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment JD DA: Off-Site Drainage Runoff =4.46 cfs @ 13.53 hrs, Volume=1.250 af, Depth= 2.31" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR, 24-HR Rainfall=4.62" Area (ac) CN Description 6.400 77 Woods, Good, HSG D 0.100 98 Paved parking & roofs 6.500 77 Weighted Average 6.400 Pervious Area 0.100 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 81.8 1,400 0.0010 0.29 5.71 Trap/Vee/Rect Channel Flow, Bot.W=6.00' D=2.00' Z= 2.0 '/' Top.W=14.00' n= 0.200 115.8 1,500 Total Subcatchment JD DA: Off-Site Drainage Runoff Hydrograph Time (hours)48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 4 3 2 1 0 Type III 24-hr 2-YR 24-HR Rainfall=4.62" Runoff Area=6.500 ac Runoff Volume=1.250 af Runoff Depth=2.31" Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 4.46 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 7Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Lot: Crowatan Lot On Site Drainage Runoff =6.34 cfs @ 12.21 hrs, Volume=0.625 af, Depth> 3.41" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR, 24-HR Rainfall=4.62" Area (ac) CN Description 2.200 89 <50% Grass cover, Poor, HSG D 2.200 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.0 100 0.0033 0.24 Sheet Flow, Fallow n= 0.050 P2= 4.62" 9.0 500 0.0033 0.92 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 16.0 600 Total Subcatchment Lot: Crowatan Lot On Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 7 6 5 4 3 2 1 0 Type III 24-hr 2-YR 24-HR Rainfall=4.62" Runoff Area=2.200 ac Runoff Volume=0.625 af Runoff Depth>3.41" Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=89 6.34 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 8Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment WDE DA: On-Site Drainage [49] Hint: Tc<2dt may require smaller dt Runoff =4.71 cfs @ 12.07 hrs, Volume=0.341 af, Depth> 3.41" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR, 24-HR Rainfall=4.62" Area (ac) CN Description 1.200 89 <50% Grass cover, Poor, HSG D 1.200 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 5.0 Direct Entry, Subcatchment WDE DA: On-Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Flo w ( c f s ) 5 4 3 2 1 0 Type III 24-hr 2-YR 24-HR Rainfall=4.62" Runoff Area=1.200 ac Runoff Volume=0.341 af Runoff Depth>3.41" Tc=5.0 min CN=89 4.71 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 9Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch [88] Warning: Qout>Qin may require Finer Routing>1 Inflow Area =13.200 ac, Inflow Depth = 2.83" for 2-YR, 24-HR event Inflow =7.58 cfs @ 14.55 hrs, Volume=3.116 af Outflow =7.58 cfs @ 14.55 hrs, Volume=3.116 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 1.69 fps, Min. Travel Time= 0.5 min Avg. Velocity = 0.70 fps, Avg. Travel Time= 1.1 min Peak Storage= 206 cf @ 14.56 hrs, Average Depth at Peak Storage= 0.91' Bank-Full Depth= 2.00', Capacity at Bank-Full= 30.39 cfs 4.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 1.0 '/' Top Width= 8.00' Length= 46.0' Slope= 0.0020 '/' Inlet Invert= 25.10', Outlet Invert= 25.01' Reach DOT-1: NCDOT R/W Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Avg. Depth=0.91' Max Vel=1.69 fps n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs 7.58 cfs7.58 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 10Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch Primary Stage-Discharge Discharge (cfs)302826242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 11Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DOT-1: NCDOT R/W Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.10 0.00 0.00 25.12 0.16 0.01 25.14 0.25 0.04 25.16 0.33 0.08 25.18 0.40 0.13 25.20 0.46 0.19 25.22 0.51 0.25 25.24 0.57 0.33 25.26 0.62 0.41 25.28 0.66 0.50 25.30 0.71 0.60 25.32 0.75 0.70 25.34 0.79 0.81 25.36 0.83 0.92 25.38 0.87 1.04 25.40 0.91 1.17 25.42 0.94 1.30 25.44 0.98 1.44 25.46 1.01 1.58 25.48 1.04 1.73 25.50 1.07 1.89 25.52 1.10 2.05 25.54 1.13 2.22 25.56 1.16 2.39 25.58 1.19 2.56 25.60 1.22 2.75 25.62 1.25 2.93 25.64 1.27 3.12 25.66 1.30 3.32 25.68 1.33 3.52 25.70 1.35 3.73 25.72 1.38 3.94 25.74 1.40 4.16 25.76 1.42 4.38 25.78 1.45 4.61 25.80 1.47 4.84 25.82 1.49 5.08 25.84 1.52 5.32 25.86 1.54 5.56 25.88 1.56 5.82 25.90 1.58 6.07 25.92 1.60 6.33 25.94 1.62 6.60 25.96 1.64 6.87 25.98 1.66 7.15 26.00 1.68 7.43 26.02 1.70 7.71 26.04 1.72 8.00 26.06 1.74 8.30 26.08 1.76 8.60 26.10 1.78 8.90 26.12 1.80 9.21 26.14 1.82 9.52 26.16 1.83 9.84 26.18 1.85 10.17 26.20 1.87 10.49 26.22 1.89 10.83 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.24 1.91 11.17 26.26 1.92 11.51 26.28 1.94 11.86 26.30 1.96 12.21 26.32 1.97 12.57 26.34 1.99 12.93 26.36 2.01 13.30 26.38 2.02 13.67 26.40 2.04 14.05 26.42 2.05 14.43 26.44 2.07 14.81 26.46 2.09 15.21 26.48 2.10 15.60 26.50 2.12 16.00 26.52 2.13 16.41 26.54 2.15 16.82 26.56 2.16 17.24 26.58 2.18 17.66 26.60 2.19 18.09 26.62 2.21 18.52 26.64 2.22 18.95 26.66 2.24 19.40 26.68 2.25 19.84 26.70 2.26 20.29 26.72 2.28 20.75 26.74 2.29 21.21 26.76 2.31 21.68 26.78 2.32 22.15 26.80 2.33 22.62 26.82 2.35 23.11 26.84 2.36 23.59 26.86 2.38 24.08 26.88 2.39 24.58 26.90 2.40 25.08 26.92 2.42 25.59 26.94 2.43 26.10 26.96 2.44 26.62 26.98 2.46 27.14 27.00 2.47 27.67 27.02 2.48 28.20 27.04 2.49 28.74 27.06 2.51 29.29 27.08 2.52 29.84 27.10 2.53 30.39 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 12Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach JD: Jurisdictional Ditch Inflow Area =8.700 ac, Inflow Depth > 2.59" for 2-YR, 24-HR event Inflow =6.99 cfs @ 12.22 hrs, Volume=1.875 af Outflow =6.65 cfs @ 12.35 hrs, Volume=1.875 af, Atten= 5%, Lag= 7.6 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 1.04 fps, Min. Travel Time= 4.2 min Avg. Velocity = 0.36 fps, Avg. Travel Time= 11.9 min Peak Storage= 1,676 cf @ 12.27 hrs, Average Depth at Peak Storage= 0.84' Bank-Full Depth= 2.00', Capacity at Bank-Full= 33.37 cfs 6.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 2.0 '/' Top Width= 14.00' Length= 260.0' Slope= 0.0008 '/' Inlet Invert= 25.40', Outlet Invert= 25.20' ‡ Reach JD: Jurisdictional Ditch InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 7 6 5 4 3 2 1 0 Inflow Area=8.700 ac Avg. Depth=0.84' Max Vel=1.04 fps n=0.030 L=260.0' S=0.0008 '/' Capacity=33.37 cfs 6.99 cfs 6.65 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 13Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach JD: Jurisdictional Ditch Primary Stage-Discharge Discharge (cfs)302520151050 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 14Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach JD: Jurisdictional Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.40 0.00 0.00 25.42 0.10 0.01 25.44 0.16 0.04 25.46 0.21 0.08 25.48 0.25 0.12 25.50 0.29 0.18 25.52 0.32 0.24 25.54 0.36 0.31 25.56 0.39 0.39 25.58 0.42 0.48 25.60 0.45 0.57 25.62 0.47 0.67 25.64 0.50 0.78 25.66 0.53 0.89 25.68 0.55 1.01 25.70 0.57 1.14 25.72 0.60 1.27 25.74 0.62 1.40 25.76 0.64 1.55 25.78 0.66 1.70 25.80 0.68 1.85 25.82 0.70 2.01 25.84 0.72 2.18 25.86 0.74 2.35 25.88 0.76 2.53 25.90 0.78 2.72 25.92 0.79 2.91 25.94 0.81 3.10 25.96 0.83 3.31 25.98 0.85 3.51 26.00 0.86 3.73 26.02 0.88 3.95 26.04 0.89 4.17 26.06 0.91 4.40 26.08 0.93 4.64 26.10 0.94 4.88 26.12 0.96 5.12 26.14 0.97 5.38 26.16 0.99 5.64 26.18 1.00 5.90 26.20 1.01 6.17 26.22 1.03 6.45 26.24 1.04 6.73 26.26 1.06 7.01 26.28 1.07 7.31 26.30 1.08 7.61 26.32 1.10 7.91 26.34 1.11 8.22 26.36 1.12 8.54 26.38 1.14 8.86 26.40 1.15 9.18 26.42 1.16 9.52 26.44 1.17 9.86 26.46 1.19 10.20 26.48 1.20 10.55 26.50 1.21 10.91 26.52 1.22 11.27 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.54 1.23 11.64 26.56 1.24 12.02 26.58 1.26 12.40 26.60 1.27 12.78 26.62 1.28 13.17 26.64 1.29 13.57 26.66 1.30 13.98 26.68 1.31 14.39 26.70 1.32 14.80 26.72 1.34 15.23 26.74 1.35 15.66 26.76 1.36 16.09 26.78 1.37 16.53 26.80 1.38 16.98 26.82 1.39 17.43 26.84 1.40 17.89 26.86 1.41 18.36 26.88 1.42 18.83 26.90 1.43 19.31 26.92 1.44 19.79 26.94 1.45 20.28 26.96 1.46 20.78 26.98 1.47 21.29 27.00 1.48 21.80 27.02 1.49 22.31 27.04 1.50 22.83 27.06 1.51 23.36 27.08 1.52 23.90 27.10 1.53 24.44 27.12 1.54 24.99 27.14 1.55 25.55 27.16 1.56 26.11 27.18 1.57 26.68 27.20 1.58 27.25 27.22 1.59 27.83 27.24 1.60 28.42 27.26 1.60 29.02 27.28 1.61 29.62 27.30 1.62 30.23 27.32 1.63 30.84 27.34 1.64 31.46 27.36 1.65 32.09 27.38 1.66 32.73 27.40 1.67 33.37 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 15Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch [91] Warning: Storage range exceeded by 0.32' [55] Hint: Peak inflow is 128% of Manning's capacity Inflow Area =43.700 ac, Inflow Depth > 2.42" for 2-YR, 24-HR event Inflow =15.20 cfs @ 16.06 hrs, Volume=8.814 af Outflow =15.15 cfs @ 16.29 hrs, Volume=8.814 af, Atten= 0%, Lag= 13.7 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 0.64 fps, Min. Travel Time= 6.8 min Avg. Velocity = 0.22 fps, Avg. Travel Time= 19.3 min Peak Storage= 6,198 cf @ 16.17 hrs, Average Depth at Peak Storage= 2.32' Bank-Full Depth= 2.00', Capacity at Bank-Full= 11.88 cfs 8.00' x 2.00' deep channel, n= 0.200 Side Slope Z-value= 1.0 '/' Top Width= 12.00' Length= 260.0' Slope= 0.0038 '/' Inlet Invert= 25.00', Outlet Invert= 24.00' Reach WDE: West Drainage Easement Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=43.700 ac Avg. Depth=2.32' Max Vel=0.64 fps n=0.200 L=260.0' S=0.0038 '/' Capacity=11.88 cfs 15.20 cfs 15.15 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 16Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch Primary Stage-Discharge Discharge (cfs)11109876543210 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 17Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach WDE: West Drainage Easement Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.00 0.00 0.00 25.02 0.03 0.01 25.04 0.05 0.02 25.06 0.07 0.03 25.08 0.08 0.05 25.10 0.10 0.08 25.12 0.11 0.11 25.14 0.12 0.14 25.16 0.13 0.17 25.18 0.14 0.21 25.20 0.15 0.25 25.22 0.16 0.29 25.24 0.17 0.34 25.26 0.18 0.39 25.28 0.19 0.44 25.30 0.20 0.49 25.32 0.21 0.55 25.34 0.21 0.61 25.36 0.22 0.67 25.38 0.23 0.73 25.40 0.24 0.80 25.42 0.24 0.86 25.44 0.25 0.93 25.46 0.26 1.00 25.48 0.26 1.08 25.50 0.27 1.15 25.52 0.28 1.23 25.54 0.28 1.31 25.56 0.29 1.39 25.58 0.30 1.48 25.60 0.30 1.56 25.62 0.31 1.65 25.64 0.31 1.74 25.66 0.32 1.83 25.68 0.33 1.92 25.70 0.33 2.02 25.72 0.34 2.12 25.74 0.34 2.22 25.76 0.35 2.32 25.78 0.35 2.42 25.80 0.36 2.52 25.82 0.36 2.63 25.84 0.37 2.74 25.86 0.37 2.85 25.88 0.38 2.96 25.90 0.38 3.07 25.92 0.39 3.19 25.94 0.39 3.30 25.96 0.40 3.42 25.98 0.40 3.54 26.00 0.41 3.67 26.02 0.41 3.79 26.04 0.42 3.92 26.06 0.42 4.04 26.08 0.43 4.17 26.10 0.43 4.30 26.12 0.43 4.43 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.14 0.44 4.57 26.16 0.44 4.70 26.18 0.45 4.84 26.20 0.45 4.98 26.22 0.46 5.12 26.24 0.46 5.26 26.26 0.46 5.41 26.28 0.47 5.55 26.30 0.47 5.70 26.32 0.48 5.85 26.34 0.48 6.00 26.36 0.48 6.15 26.38 0.49 6.31 26.40 0.49 6.46 26.42 0.49 6.62 26.44 0.50 6.78 26.46 0.50 6.94 26.48 0.51 7.10 26.50 0.51 7.27 26.52 0.51 7.43 26.54 0.52 7.60 26.56 0.52 7.77 26.58 0.52 7.94 26.60 0.53 8.11 26.62 0.53 8.28 26.64 0.53 8.46 26.66 0.54 8.63 26.68 0.54 8.81 26.70 0.55 8.99 26.72 0.55 9.17 26.74 0.55 9.36 26.76 0.56 9.54 26.78 0.56 9.73 26.80 0.56 9.92 26.82 0.57 10.11 26.84 0.57 10.30 26.86 0.57 10.49 26.88 0.58 10.68 26.90 0.58 10.88 26.92 0.58 11.08 26.94 0.58 11.28 26.96 0.59 11.48 26.98 0.59 11.68 27.00 0.59 11.88 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 18Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe [57] Hint: Peaked at 28.09' (Flood elevation advised) [63] Warning: Exceeded Reach DOT-1 inflow depth by 2.08' @ 14.55 hrs Inflow Area =13.200 ac, Inflow Depth = 2.83" for 2-YR, 24-HR event Inflow =7.58 cfs @ 14.55 hrs, Volume=3.116 af Outflow =7.58 cfs @ 14.55 hrs, Volume=3.116 af, Atten= 0%, Lag= 0.0 min Primary =7.58 cfs @ 14.55 hrs, Volume=3.116 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 28.09' @ 14.55 hrs Device Routing Invert Outlet Devices #1 Primary 25.01'15.0" x 84.0' long Culvert CPP, mitered to conform to fill, Ke= 0.700 Outlet Invert= 25.00' S= 0.0001 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean Primary OutFlow Max=7.58 cfs @ 14.55 hrs HW=28.09' (Free Discharge) 1=Culvert (Barrel Controls 7.58 cfs @ 6.18 fps) Pond C-1: Driveway Pipe InflowPrimary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Peak Elev=28.09' 15.0" x 84.0' Culvert 7.58 cfs 7.58 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 19Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe Primary Stage-Discharge Discharge (cfs)76543210 El e v a t i o n ( f e e t ) 28 27 26 Culvert DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 20Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond C-1: Driveway Pipe Elevation (feet) Primary (cfs) 25.01 0.00 25.03 0.00 25.05 0.00 25.07 0.00 25.09 0.01 25.11 0.01 25.13 0.02 25.15 0.02 25.17 0.03 25.19 0.04 25.21 0.06 25.23 0.07 25.25 0.09 25.27 0.10 25.29 0.12 25.31 0.14 25.33 0.17 25.35 0.19 25.37 0.22 25.39 0.25 25.41 0.28 25.43 0.31 25.45 0.34 25.47 0.38 25.49 0.42 25.51 0.45 25.53 0.50 25.55 0.54 25.57 0.58 25.59 0.63 25.61 0.67 25.63 0.72 25.65 0.77 25.67 0.82 25.69 0.87 25.71 0.92 25.73 0.98 25.75 1.03 25.77 1.09 25.79 1.15 25.81 1.21 25.83 1.27 25.85 1.33 25.87 1.39 25.89 1.45 25.91 1.51 25.93 1.58 25.95 1.64 25.97 1.71 25.99 1.77 26.01 1.84 26.03 1.91 26.05 1.98 26.07 2.04 26.09 2.11 26.11 2.18 26.13 2.25 Elevation (feet) Primary (cfs) 26.15 2.32 26.17 2.39 26.19 2.45 26.21 2.52 26.23 2.59 26.25 2.66 26.27 2.73 26.29 2.79 26.31 2.86 26.33 2.93 26.35 2.99 26.37 3.05 26.39 3.12 26.41 3.18 26.43 3.24 26.45 3.29 26.47 3.35 26.49 3.40 26.51 3.46 26.53 3.50 26.55 3.55 26.57 3.59 26.59 3.63 26.61 3.66 26.63 3.68 26.65 3.70 26.67 3.69 26.69 3.71 26.71 3.79 26.73 3.87 26.75 3.95 26.77 4.03 26.79 4.11 26.81 4.18 26.83 4.26 26.85 4.33 26.87 4.40 26.89 4.47 26.91 4.54 26.93 4.61 26.95 4.68 26.97 4.74 26.99 4.81 27.01 4.87 27.03 4.94 27.05 5.00 27.07 5.06 27.09 5.12 27.11 5.18 27.13 5.24 27.15 5.30 27.17 5.36 27.19 5.42 27.21 5.48 27.23 5.53 27.25 5.59 27.27 5.65 Elevation (feet) Primary (cfs) 27.29 5.70 27.31 5.76 27.33 5.81 27.35 5.86 27.37 5.92 27.39 5.97 27.41 6.02 27.43 6.07 27.45 6.12 27.47 6.18 27.49 6.23 27.51 6.28 27.53 6.33 27.55 6.37 27.57 6.42 27.59 6.47 27.61 6.52 27.63 6.57 27.65 6.62 27.67 6.66 27.69 6.71 27.71 6.76 27.73 6.80 27.75 6.85 27.77 6.89 27.79 6.94 27.81 6.98 27.83 7.03 27.85 7.07 27.87 7.12 27.89 7.16 27.91 7.20 27.93 7.25 27.95 7.29 27.97 7.33 27.99 7.38 28.01 7.42 28.03 7.46 28.05 7.50 28.07 7.54 28.09 7.58 28.11 7.63 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 21Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=13.200 ac Runoff Depth=5.19"Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Of Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 Runoff=13.91 cfs 5.707 af Runoff Area=42.500 ac Runoff Depth=4.63"Subcatchment Easement: Off-Site Drainage Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 Runoff=29.55 cfs 16.396 af Runoff Area=6.500 ac Runoff Depth=4.52"Subcatchment JD DA: Off-Site Drainage Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 Runoff=8.85 cfs 2.448 af Runoff Area=2.200 ac Runoff Depth>5.86"Subcatchment Lot: Crowatan Lot On Site Drainage Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=89 Runoff=10.65 cfs 1.075 af Runoff Area=1.200 ac Runoff Depth>5.86"Subcatchment WDE DA: On-Site Drainage Tc=5.0 min CN=89 Runoff=7.89 cfs 0.586 af Avg. Depth=1.29' Max Vel=2.03 fps Inflow=13.91 cfs 5.707 afReach DOT-1: NCDOT R/W Ditch n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs Outflow=13.90 cfs 5.707 af Avg. Depth=1.16' Max Vel=1.24 fps Inflow=12.34 cfs 3.522 afReach JD: Jurisdictional Ditch n=0.030 L=260.0' S=0.0008 '/' Capacity=33.37 cfs Outflow=11.93 cfs 3.522 af Avg. Depth=3.74' Max Vel=0.73 fps Inflow=29.77 cfs 16.981 afReach WDE: West Drainage Easement Ditc n=0.200 L=260.0' S=0.0038 '/' Capacity=11.88 cfs Outflow=29.69 cfs 16.981 af Peak Elev=32.74' Inflow=13.90 cfs 5.707 afPond C-1: Driveway Pipe 15.0" x 84.0' Culvert Outflow=13.90 cfs 5.707 af Total Runoff Area = 65.600 ac Runoff Volume = 26.211 af Average Runoff Depth = 4.79" 98.63% Pervious Area = 64.700 ac 1.37% Impervious Area = 0.900 ac DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 22Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Off-Site) Runoff =13.91 cfs @ 14.51 hrs, Volume=5.707 af, Depth= 5.19" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR, 24-HR Rainfall=7.17" Area (ac) CN Description 6.600 77 Woods, Good, HSG D 0.600 98 Paved parking & roofs 6.000 89 <50% Grass cover, Poor, HSG D 13.200 83 Weighted Average 12.600 Pervious Area 0.600 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, Dense woods n= 0.200 P2= 4.62" 31.6 150 0.0010 0.08 Shallow Concentrated Flow, Dense woods Forest w/Heavy Litter Kv= 2.5 fps 135.0 2,200 0.0010 0.27 3.26 Trap/Vee/Rect Channel Flow, Channel Bot.W=4.00' D=2.00' Z= 1.0 '/' Top.W=8.00' n= 0.200 200.6 2,450 Total Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Off-Site) Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 10-YR 24-HR Rainfall=7.17" Runoff Area=13.200 ac Runoff Volume=5.707 af Runoff Depth=5.19" Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 13.91 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 23Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Easement: Off-Site Drainage Runoff =29.55 cfs @ 16.05 hrs, Volume=16.396 af, Depth= 4.63" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR, 24-HR Rainfall=7.17" Area (ac) CN Description 34.500 77 Woods, Good, HSG D 0.900 89 Dirt roads, HSG D 6.900 80 >75% Grass cover, Good, HSG D 0.200 98 Paved parking & roofs 42.500 78 Weighted Average 42.300 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 42.2 200 0.0010 0.08 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 231.0 4,200 0.0010 0.30 6.06 Trap/Vee/Rect Channel Flow, Bot.W=8.00' D=2.00' Z= 1.0 '/' Top.W=12.00' n= 0.200 307.2 4,500 Total Subcatchment Easement: Off-Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type III 24-hr 10-YR 24-HR Rainfall=7.17" Runoff Area=42.500 ac Runoff Volume=16.396 af Runoff Depth=4.63" Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 29.55 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 24Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment JD DA: Off-Site Drainage Runoff =8.85 cfs @ 13.51 hrs, Volume=2.448 af, Depth= 4.52" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR, 24-HR Rainfall=7.17" Area (ac) CN Description 6.400 77 Woods, Good, HSG D 0.100 98 Paved parking & roofs 6.500 77 Weighted Average 6.400 Pervious Area 0.100 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 81.8 1,400 0.0010 0.29 5.71 Trap/Vee/Rect Channel Flow, Bot.W=6.00' D=2.00' Z= 2.0 '/' Top.W=14.00' n= 0.200 115.8 1,500 Total Subcatchment JD DA: Off-Site Drainage Runoff Hydrograph Time (hours)48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 10-YR 24-HR Rainfall=7.17" Runoff Area=6.500 ac Runoff Volume=2.448 af Runoff Depth=4.52" Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 8.85 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 25Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Lot: Crowatan Lot On Site Drainage Runoff =10.65 cfs @ 12.21 hrs, Volume=1.075 af, Depth> 5.86" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR, 24-HR Rainfall=7.17" Area (ac) CN Description 2.200 89 <50% Grass cover, Poor, HSG D 2.200 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.0 100 0.0033 0.24 Sheet Flow, Fallow n= 0.050 P2= 4.62" 9.0 500 0.0033 0.92 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 16.0 600 Total Subcatchment Lot: Crowatan Lot On Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 10-YR 24-HR Rainfall=7.17" Runoff Area=2.200 ac Runoff Volume=1.075 af Runoff Depth>5.86" Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=89 10.65 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 26Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment WDE DA: On-Site Drainage [49] Hint: Tc<2dt may require smaller dt Runoff =7.89 cfs @ 12.07 hrs, Volume=0.586 af, Depth> 5.86" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR, 24-HR Rainfall=7.17" Area (ac) CN Description 1.200 89 <50% Grass cover, Poor, HSG D 1.200 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 5.0 Direct Entry, Subcatchment WDE DA: On-Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Flo w ( c f s ) 8 7 6 5 4 3 2 1 0 Type III 24-hr 10-YR 24-HR Rainfall=7.17" Runoff Area=1.200 ac Runoff Volume=0.586 af Runoff Depth>5.86" Tc=5.0 min CN=89 7.89 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 27Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch Inflow Area =13.200 ac, Inflow Depth = 5.19" for 10-YR, 24-HR event Inflow =13.91 cfs @ 14.51 hrs, Volume=5.707 af Outflow =13.90 cfs @ 14.52 hrs, Volume=5.707 af, Atten= 0%, Lag= 0.7 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 2.03 fps, Min. Travel Time= 0.4 min Avg. Velocity = 0.82 fps, Avg. Travel Time= 0.9 min Peak Storage= 315 cf @ 14.52 hrs, Average Depth at Peak Storage= 1.29' Bank-Full Depth= 2.00', Capacity at Bank-Full= 30.39 cfs 4.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 1.0 '/' Top Width= 8.00' Length= 46.0' Slope= 0.0020 '/' Inlet Invert= 25.10', Outlet Invert= 25.01' Reach DOT-1: NCDOT R/W Ditch InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Avg. Depth=1.29' Max Vel=2.03 fps n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs 13.91 cfs13.90 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 28Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch Primary Stage-Discharge Discharge (cfs)302826242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 29Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DOT-1: NCDOT R/W Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.10 0.00 0.00 25.12 0.16 0.01 25.14 0.25 0.04 25.16 0.33 0.08 25.18 0.40 0.13 25.20 0.46 0.19 25.22 0.51 0.25 25.24 0.57 0.33 25.26 0.62 0.41 25.28 0.66 0.50 25.30 0.71 0.60 25.32 0.75 0.70 25.34 0.79 0.81 25.36 0.83 0.92 25.38 0.87 1.04 25.40 0.91 1.17 25.42 0.94 1.30 25.44 0.98 1.44 25.46 1.01 1.58 25.48 1.04 1.73 25.50 1.07 1.89 25.52 1.10 2.05 25.54 1.13 2.22 25.56 1.16 2.39 25.58 1.19 2.56 25.60 1.22 2.75 25.62 1.25 2.93 25.64 1.27 3.12 25.66 1.30 3.32 25.68 1.33 3.52 25.70 1.35 3.73 25.72 1.38 3.94 25.74 1.40 4.16 25.76 1.42 4.38 25.78 1.45 4.61 25.80 1.47 4.84 25.82 1.49 5.08 25.84 1.52 5.32 25.86 1.54 5.56 25.88 1.56 5.82 25.90 1.58 6.07 25.92 1.60 6.33 25.94 1.62 6.60 25.96 1.64 6.87 25.98 1.66 7.15 26.00 1.68 7.43 26.02 1.70 7.71 26.04 1.72 8.00 26.06 1.74 8.30 26.08 1.76 8.60 26.10 1.78 8.90 26.12 1.80 9.21 26.14 1.82 9.52 26.16 1.83 9.84 26.18 1.85 10.17 26.20 1.87 10.49 26.22 1.89 10.83 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.24 1.91 11.17 26.26 1.92 11.51 26.28 1.94 11.86 26.30 1.96 12.21 26.32 1.97 12.57 26.34 1.99 12.93 26.36 2.01 13.30 26.38 2.02 13.67 26.40 2.04 14.05 26.42 2.05 14.43 26.44 2.07 14.81 26.46 2.09 15.21 26.48 2.10 15.60 26.50 2.12 16.00 26.52 2.13 16.41 26.54 2.15 16.82 26.56 2.16 17.24 26.58 2.18 17.66 26.60 2.19 18.09 26.62 2.21 18.52 26.64 2.22 18.95 26.66 2.24 19.40 26.68 2.25 19.84 26.70 2.26 20.29 26.72 2.28 20.75 26.74 2.29 21.21 26.76 2.31 21.68 26.78 2.32 22.15 26.80 2.33 22.62 26.82 2.35 23.11 26.84 2.36 23.59 26.86 2.38 24.08 26.88 2.39 24.58 26.90 2.40 25.08 26.92 2.42 25.59 26.94 2.43 26.10 26.96 2.44 26.62 26.98 2.46 27.14 27.00 2.47 27.67 27.02 2.48 28.20 27.04 2.49 28.74 27.06 2.51 29.29 27.08 2.52 29.84 27.10 2.53 30.39 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 30Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach JD: Jurisdictional Ditch [82] Warning: Early inflow requires earlier time span Inflow Area =8.700 ac, Inflow Depth > 4.86" for 10-YR, 24-HR event Inflow =12.34 cfs @ 12.22 hrs, Volume=3.522 af Outflow =11.93 cfs @ 12.32 hrs, Volume=3.522 af, Atten= 3%, Lag= 6.2 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 1.24 fps, Min. Travel Time= 3.5 min Avg. Velocity = 0.45 fps, Avg. Travel Time= 9.6 min Peak Storage= 2,506 cf @ 12.27 hrs, Average Depth at Peak Storage= 1.16' Bank-Full Depth= 2.00', Capacity at Bank-Full= 33.37 cfs 6.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 2.0 '/' Top Width= 14.00' Length= 260.0' Slope= 0.0008 '/' Inlet Invert= 25.40', Outlet Invert= 25.20' ‡ Reach JD: Jurisdictional Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=8.700 ac Avg. Depth=1.16' Max Vel=1.24 fps n=0.030 L=260.0' S=0.0008 '/' Capacity=33.37 cfs 12.34 cfs 11.93 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 31Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach JD: Jurisdictional Ditch Primary Stage-Discharge Discharge (cfs)302520151050 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 32Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach JD: Jurisdictional Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.40 0.00 0.00 25.42 0.10 0.01 25.44 0.16 0.04 25.46 0.21 0.08 25.48 0.25 0.12 25.50 0.29 0.18 25.52 0.32 0.24 25.54 0.36 0.31 25.56 0.39 0.39 25.58 0.42 0.48 25.60 0.45 0.57 25.62 0.47 0.67 25.64 0.50 0.78 25.66 0.53 0.89 25.68 0.55 1.01 25.70 0.57 1.14 25.72 0.60 1.27 25.74 0.62 1.40 25.76 0.64 1.55 25.78 0.66 1.70 25.80 0.68 1.85 25.82 0.70 2.01 25.84 0.72 2.18 25.86 0.74 2.35 25.88 0.76 2.53 25.90 0.78 2.72 25.92 0.79 2.91 25.94 0.81 3.10 25.96 0.83 3.31 25.98 0.85 3.51 26.00 0.86 3.73 26.02 0.88 3.95 26.04 0.89 4.17 26.06 0.91 4.40 26.08 0.93 4.64 26.10 0.94 4.88 26.12 0.96 5.12 26.14 0.97 5.38 26.16 0.99 5.64 26.18 1.00 5.90 26.20 1.01 6.17 26.22 1.03 6.45 26.24 1.04 6.73 26.26 1.06 7.01 26.28 1.07 7.31 26.30 1.08 7.61 26.32 1.10 7.91 26.34 1.11 8.22 26.36 1.12 8.54 26.38 1.14 8.86 26.40 1.15 9.18 26.42 1.16 9.52 26.44 1.17 9.86 26.46 1.19 10.20 26.48 1.20 10.55 26.50 1.21 10.91 26.52 1.22 11.27 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.54 1.23 11.64 26.56 1.24 12.02 26.58 1.26 12.40 26.60 1.27 12.78 26.62 1.28 13.17 26.64 1.29 13.57 26.66 1.30 13.98 26.68 1.31 14.39 26.70 1.32 14.80 26.72 1.34 15.23 26.74 1.35 15.66 26.76 1.36 16.09 26.78 1.37 16.53 26.80 1.38 16.98 26.82 1.39 17.43 26.84 1.40 17.89 26.86 1.41 18.36 26.88 1.42 18.83 26.90 1.43 19.31 26.92 1.44 19.79 26.94 1.45 20.28 26.96 1.46 20.78 26.98 1.47 21.29 27.00 1.48 21.80 27.02 1.49 22.31 27.04 1.50 22.83 27.06 1.51 23.36 27.08 1.52 23.90 27.10 1.53 24.44 27.12 1.54 24.99 27.14 1.55 25.55 27.16 1.56 26.11 27.18 1.57 26.68 27.20 1.58 27.25 27.22 1.59 27.83 27.24 1.60 28.42 27.26 1.60 29.02 27.28 1.61 29.62 27.30 1.62 30.23 27.32 1.63 30.84 27.34 1.64 31.46 27.36 1.65 32.09 27.38 1.66 32.73 27.40 1.67 33.37 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 33Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch [91] Warning: Storage range exceeded by 1.74' [55] Hint: Peak inflow is 250% of Manning's capacity Inflow Area =43.700 ac, Inflow Depth > 4.66" for 10-YR, 24-HR event Inflow =29.77 cfs @ 16.05 hrs, Volume=16.981 af Outflow =29.69 cfs @ 16.21 hrs, Volume=16.981 af, Atten= 0%, Lag= 10.1 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 0.73 fps, Min. Travel Time= 6.0 min Avg. Velocity = 0.28 fps, Avg. Travel Time= 15.7 min Peak Storage= 10,635 cf @ 16.12 hrs, Average Depth at Peak Storage= 3.74' Bank-Full Depth= 2.00', Capacity at Bank-Full= 11.88 cfs 8.00' x 2.00' deep channel, n= 0.200 Side Slope Z-value= 1.0 '/' Top Width= 12.00' Length= 260.0' Slope= 0.0038 '/' Inlet Invert= 25.00', Outlet Invert= 24.00' Reach WDE: West Drainage Easement Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=43.700 ac Avg. Depth=3.74' Max Vel=0.73 fps n=0.200 L=260.0' S=0.0038 '/' Capacity=11.88 cfs 29.77 cfs 29.69 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 34Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch Primary Stage-Discharge Discharge (cfs)11109876543210 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 35Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach WDE: West Drainage Easement Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.00 0.00 0.00 25.02 0.03 0.01 25.04 0.05 0.02 25.06 0.07 0.03 25.08 0.08 0.05 25.10 0.10 0.08 25.12 0.11 0.11 25.14 0.12 0.14 25.16 0.13 0.17 25.18 0.14 0.21 25.20 0.15 0.25 25.22 0.16 0.29 25.24 0.17 0.34 25.26 0.18 0.39 25.28 0.19 0.44 25.30 0.20 0.49 25.32 0.21 0.55 25.34 0.21 0.61 25.36 0.22 0.67 25.38 0.23 0.73 25.40 0.24 0.80 25.42 0.24 0.86 25.44 0.25 0.93 25.46 0.26 1.00 25.48 0.26 1.08 25.50 0.27 1.15 25.52 0.28 1.23 25.54 0.28 1.31 25.56 0.29 1.39 25.58 0.30 1.48 25.60 0.30 1.56 25.62 0.31 1.65 25.64 0.31 1.74 25.66 0.32 1.83 25.68 0.33 1.92 25.70 0.33 2.02 25.72 0.34 2.12 25.74 0.34 2.22 25.76 0.35 2.32 25.78 0.35 2.42 25.80 0.36 2.52 25.82 0.36 2.63 25.84 0.37 2.74 25.86 0.37 2.85 25.88 0.38 2.96 25.90 0.38 3.07 25.92 0.39 3.19 25.94 0.39 3.30 25.96 0.40 3.42 25.98 0.40 3.54 26.00 0.41 3.67 26.02 0.41 3.79 26.04 0.42 3.92 26.06 0.42 4.04 26.08 0.43 4.17 26.10 0.43 4.30 26.12 0.43 4.43 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.14 0.44 4.57 26.16 0.44 4.70 26.18 0.45 4.84 26.20 0.45 4.98 26.22 0.46 5.12 26.24 0.46 5.26 26.26 0.46 5.41 26.28 0.47 5.55 26.30 0.47 5.70 26.32 0.48 5.85 26.34 0.48 6.00 26.36 0.48 6.15 26.38 0.49 6.31 26.40 0.49 6.46 26.42 0.49 6.62 26.44 0.50 6.78 26.46 0.50 6.94 26.48 0.51 7.10 26.50 0.51 7.27 26.52 0.51 7.43 26.54 0.52 7.60 26.56 0.52 7.77 26.58 0.52 7.94 26.60 0.53 8.11 26.62 0.53 8.28 26.64 0.53 8.46 26.66 0.54 8.63 26.68 0.54 8.81 26.70 0.55 8.99 26.72 0.55 9.17 26.74 0.55 9.36 26.76 0.56 9.54 26.78 0.56 9.73 26.80 0.56 9.92 26.82 0.57 10.11 26.84 0.57 10.30 26.86 0.57 10.49 26.88 0.58 10.68 26.90 0.58 10.88 26.92 0.58 11.08 26.94 0.58 11.28 26.96 0.59 11.48 26.98 0.59 11.68 27.00 0.59 11.88 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 36Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe [57] Hint: Peaked at 32.74' (Flood elevation advised) [63] Warning: Exceeded Reach DOT-1 inflow depth by 6.34' @ 14.55 hrs Inflow Area =13.200 ac, Inflow Depth = 5.19" for 10-YR, 24-HR event Inflow =13.90 cfs @ 14.52 hrs, Volume=5.707 af Outflow =13.90 cfs @ 14.52 hrs, Volume=5.707 af, Atten= 0%, Lag= 0.0 min Primary =13.90 cfs @ 14.52 hrs, Volume=5.707 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 32.74' @ 14.52 hrs Device Routing Invert Outlet Devices #1 Primary 25.01'15.0" x 84.0' long Culvert CPP, mitered to conform to fill, Ke= 0.700 Outlet Invert= 25.00' S= 0.0001 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean Primary OutFlow Max=13.89 cfs @ 14.52 hrs HW=32.74' (Free Discharge) 1=Culvert (Inlet Controls 13.89 cfs @ 11.32 fps) Pond C-1: Driveway Pipe InflowPrimary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Peak Elev=32.74' 15.0" x 84.0' Culvert 13.90 cfs 13.90 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 37Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe Primary Stage-Discharge Discharge (cfs)131211109876543210 El e v a t i o n ( f e e t ) 32 31 30 29 28 27 26 Culvert DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 38Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond C-1: Driveway Pipe Elevation (feet) Primary (cfs) 25.01 0.00 25.05 0.00 25.09 0.01 25.13 0.02 25.17 0.03 25.21 0.06 25.25 0.09 25.29 0.12 25.33 0.17 25.37 0.22 25.41 0.28 25.45 0.34 25.49 0.42 25.53 0.50 25.57 0.58 25.61 0.67 25.65 0.77 25.69 0.87 25.73 0.98 25.77 1.09 25.81 1.21 25.85 1.33 25.89 1.45 25.93 1.58 25.97 1.71 26.01 1.84 26.05 1.98 26.09 2.11 26.13 2.25 26.17 2.39 26.21 2.52 26.25 2.66 26.29 2.79 26.33 2.93 26.37 3.05 26.41 3.18 26.45 3.29 26.49 3.40 26.53 3.50 26.57 3.59 26.61 3.66 26.65 3.70 26.69 3.71 26.73 3.87 26.77 4.03 26.81 4.18 26.85 4.33 26.89 4.47 26.93 4.61 26.97 4.74 27.01 4.87 27.05 5.00 27.09 5.12 27.13 5.24 27.17 5.36 27.21 5.48 27.25 5.59 Elevation (feet) Primary (cfs) 27.29 5.70 27.33 5.81 27.37 5.92 27.41 6.02 27.45 6.12 27.49 6.23 27.53 6.33 27.57 6.42 27.61 6.52 27.65 6.62 27.69 6.71 27.73 6.80 27.77 6.89 27.81 6.98 27.85 7.07 27.89 7.16 27.93 7.25 27.97 7.33 28.01 7.42 28.05 7.50 28.09 7.58 28.13 7.67 28.17 7.75 28.21 7.83 28.25 7.91 28.29 7.99 28.33 8.06 28.37 8.14 28.41 8.22 28.45 8.29 28.49 8.37 28.53 8.44 28.57 8.52 28.61 8.59 28.65 8.66 28.69 8.73 28.73 8.80 28.77 8.88 28.81 8.95 28.85 9.02 28.89 9.08 28.93 9.15 28.97 9.22 29.01 9.29 29.05 9.36 29.09 9.42 29.13 9.49 29.17 9.55 29.21 9.62 29.25 9.68 29.29 9.75 29.33 9.81 29.37 9.88 29.41 9.94 29.45 10.00 29.49 10.06 29.53 10.13 Elevation (feet) Primary (cfs) 29.57 10.19 29.61 10.25 29.65 10.31 29.69 10.37 29.73 10.43 29.77 10.49 29.81 10.55 29.85 10.61 29.89 10.67 29.93 10.73 29.97 10.78 30.01 10.84 30.05 10.90 30.09 10.96 30.13 11.01 30.17 11.07 30.21 11.13 30.25 11.18 30.29 11.24 30.33 11.29 30.37 11.35 30.41 11.39 30.45 11.44 30.49 11.49 30.53 11.54 30.57 11.58 30.61 11.63 30.65 11.68 30.69 11.72 30.73 11.77 30.77 11.81 30.81 11.86 30.85 11.91 30.89 11.95 30.93 12.00 30.97 12.04 31.01 12.09 31.05 12.13 31.09 12.18 31.13 12.22 31.17 12.27 31.21 12.31 31.25 12.35 31.29 12.40 31.33 12.44 31.37 12.49 31.41 12.53 31.45 12.57 31.49 12.62 31.53 12.66 31.57 12.70 31.61 12.74 31.65 12.79 31.69 12.83 31.73 12.87 31.77 12.91 31.81 12.96 Elevation (feet) Primary (cfs) 31.85 13.00 31.89 13.04 31.93 13.08 31.97 13.12 32.01 13.16 32.05 13.21 32.09 13.25 32.13 13.29 32.17 13.33 32.21 13.37 32.25 13.41 32.29 13.45 32.33 13.49 32.37 13.53 32.41 13.57 32.45 13.61 32.49 13.65 32.53 13.69 32.57 13.73 32.61 13.77 32.65 13.81 32.69 13.85 32.73 13.89 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 39Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=13.200 ac Runoff Depth=6.95"Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Of Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 Runoff=18.53 cfs 7.641 af Runoff Area=42.500 ac Runoff Depth=6.33"Subcatchment Easement: Off-Site Drainage Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 Runoff=40.41 cfs 22.424 af Runoff Area=6.500 ac Runoff Depth=6.21"Subcatchment JD DA: Off-Site Drainage Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 Runoff=12.12 cfs 3.363 af Runoff Area=2.200 ac Runoff Depth>7.64"Subcatchment Lot: Crowatan Lot On Site Drainage Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=89 Runoff=13.72 cfs 1.401 af Runoff Area=1.200 ac Runoff Depth>7.64"Subcatchment WDE DA: On-Site Drainage Tc=5.0 min CN=89 Runoff=10.16 cfs 0.764 af Avg. Depth=1.52' Max Vel=2.21 fps Inflow=18.53 cfs 7.641 afReach DOT-1: NCDOT R/W Ditch n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs Outflow=18.52 cfs 7.641 af Avg. Depth=1.35' Max Vel=1.35 fps Inflow=16.26 cfs 4.764 afReach JD: Jurisdictional Ditch n=0.030 L=260.0' S=0.0008 '/' Capacity=33.37 cfs Outflow=15.83 cfs 4.764 af Avg. Depth=4.81' Max Vel=0.76 fps Inflow=40.70 cfs 23.188 afReach WDE: West Drainage Easement Ditc n=0.200 L=260.0' S=0.0038 '/' Capacity=11.88 cfs Outflow=40.60 cfs 23.188 af Peak Elev=38.26' Inflow=18.52 cfs 7.641 afPond C-1: Driveway Pipe 15.0" x 84.0' Culvert Outflow=18.52 cfs 7.641 af Total Runoff Area = 65.600 ac Runoff Volume = 35.593 af Average Runoff Depth = 6.51" 98.63% Pervious Area = 64.700 ac 1.37% Impervious Area = 0.900 ac DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 40Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Off-Site) Runoff =18.53 cfs @ 14.51 hrs, Volume=7.641 af, Depth= 6.95" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR, 24-HR Rainfall=9.01" Area (ac) CN Description 6.600 77 Woods, Good, HSG D 0.600 98 Paved parking & roofs 6.000 89 <50% Grass cover, Poor, HSG D 13.200 83 Weighted Average 12.600 Pervious Area 0.600 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, Dense woods n= 0.200 P2= 4.62" 31.6 150 0.0010 0.08 Shallow Concentrated Flow, Dense woods Forest w/Heavy Litter Kv= 2.5 fps 135.0 2,200 0.0010 0.27 3.26 Trap/Vee/Rect Channel Flow, Channel Bot.W=4.00' D=2.00' Z= 1.0 '/' Top.W=8.00' n= 0.200 200.6 2,450 Total Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Off-Site) Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25-YR 24-HR Rainfall=9.01" Runoff Area=13.200 ac Runoff Volume=7.641 af Runoff Depth=6.95" Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 18.53 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 41Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Easement: Off-Site Drainage Runoff =40.41 cfs @ 16.04 hrs, Volume=22.424 af, Depth= 6.33" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR, 24-HR Rainfall=9.01" Area (ac) CN Description 34.500 77 Woods, Good, HSG D 0.900 89 Dirt roads, HSG D 6.900 80 >75% Grass cover, Good, HSG D 0.200 98 Paved parking & roofs 42.500 78 Weighted Average 42.300 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 42.2 200 0.0010 0.08 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 231.0 4,200 0.0010 0.30 6.06 Trap/Vee/Rect Channel Flow, Bot.W=8.00' D=2.00' Z= 1.0 '/' Top.W=12.00' n= 0.200 307.2 4,500 Total Subcatchment Easement: Off-Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type III 24-hr 25-YR 24-HR Rainfall=9.01" Runoff Area=42.500 ac Runoff Volume=22.424 af Runoff Depth=6.33" Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 40.41 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 42Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment JD DA: Off-Site Drainage Runoff =12.12 cfs @ 13.50 hrs, Volume=3.363 af, Depth= 6.21" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR, 24-HR Rainfall=9.01" Area (ac) CN Description 6.400 77 Woods, Good, HSG D 0.100 98 Paved parking & roofs 6.500 77 Weighted Average 6.400 Pervious Area 0.100 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 81.8 1,400 0.0010 0.29 5.71 Trap/Vee/Rect Channel Flow, Bot.W=6.00' D=2.00' Z= 2.0 '/' Top.W=14.00' n= 0.200 115.8 1,500 Total Subcatchment JD DA: Off-Site Drainage Runoff Hydrograph Time (hours)48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25-YR 24-HR Rainfall=9.01" Runoff Area=6.500 ac Runoff Volume=3.363 af Runoff Depth=6.21" Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 12.12 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 43Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Lot: Crowatan Lot On Site Drainage Runoff =13.72 cfs @ 12.21 hrs, Volume=1.401 af, Depth> 7.64" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR, 24-HR Rainfall=9.01" Area (ac) CN Description 2.200 89 <50% Grass cover, Poor, HSG D 2.200 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.0 100 0.0033 0.24 Sheet Flow, Fallow n= 0.050 P2= 4.62" 9.0 500 0.0033 0.92 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 16.0 600 Total Subcatchment Lot: Crowatan Lot On Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25-YR 24-HR Rainfall=9.01" Runoff Area=2.200 ac Runoff Volume=1.401 af Runoff Depth>7.64" Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=89 13.72 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 44Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment WDE DA: On-Site Drainage [49] Hint: Tc<2dt may require smaller dt Runoff =10.16 cfs @ 12.07 hrs, Volume=0.764 af, Depth> 7.64" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR, 24-HR Rainfall=9.01" Area (ac) CN Description 1.200 89 <50% Grass cover, Poor, HSG D 1.200 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 5.0 Direct Entry, Subcatchment WDE DA: On-Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Flo w ( c f s ) 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25-YR 24-HR Rainfall=9.01" Runoff Area=1.200 ac Runoff Volume=0.764 af Runoff Depth>7.64" Tc=5.0 min CN=89 10.16 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 45Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch Inflow Area =13.200 ac, Inflow Depth = 6.95" for 25-YR, 24-HR event Inflow =18.53 cfs @ 14.51 hrs, Volume=7.641 af Outflow =18.52 cfs @ 14.52 hrs, Volume=7.641 af, Atten= 0%, Lag= 0.6 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 2.21 fps, Min. Travel Time= 0.3 min Avg. Velocity = 0.91 fps, Avg. Travel Time= 0.8 min Peak Storage= 386 cf @ 14.51 hrs, Average Depth at Peak Storage= 1.52' Bank-Full Depth= 2.00', Capacity at Bank-Full= 30.39 cfs 4.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 1.0 '/' Top Width= 8.00' Length= 46.0' Slope= 0.0020 '/' Inlet Invert= 25.10', Outlet Invert= 25.01' Reach DOT-1: NCDOT R/W Ditch InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Avg. Depth=1.52' Max Vel=2.21 fps n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs 18.53 cfs18.52 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 46Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch Primary Stage-Discharge Discharge (cfs)302826242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 47Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DOT-1: NCDOT R/W Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.10 0.00 0.00 25.12 0.16 0.01 25.14 0.25 0.04 25.16 0.33 0.08 25.18 0.40 0.13 25.20 0.46 0.19 25.22 0.51 0.25 25.24 0.57 0.33 25.26 0.62 0.41 25.28 0.66 0.50 25.30 0.71 0.60 25.32 0.75 0.70 25.34 0.79 0.81 25.36 0.83 0.92 25.38 0.87 1.04 25.40 0.91 1.17 25.42 0.94 1.30 25.44 0.98 1.44 25.46 1.01 1.58 25.48 1.04 1.73 25.50 1.07 1.89 25.52 1.10 2.05 25.54 1.13 2.22 25.56 1.16 2.39 25.58 1.19 2.56 25.60 1.22 2.75 25.62 1.25 2.93 25.64 1.27 3.12 25.66 1.30 3.32 25.68 1.33 3.52 25.70 1.35 3.73 25.72 1.38 3.94 25.74 1.40 4.16 25.76 1.42 4.38 25.78 1.45 4.61 25.80 1.47 4.84 25.82 1.49 5.08 25.84 1.52 5.32 25.86 1.54 5.56 25.88 1.56 5.82 25.90 1.58 6.07 25.92 1.60 6.33 25.94 1.62 6.60 25.96 1.64 6.87 25.98 1.66 7.15 26.00 1.68 7.43 26.02 1.70 7.71 26.04 1.72 8.00 26.06 1.74 8.30 26.08 1.76 8.60 26.10 1.78 8.90 26.12 1.80 9.21 26.14 1.82 9.52 26.16 1.83 9.84 26.18 1.85 10.17 26.20 1.87 10.49 26.22 1.89 10.83 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.24 1.91 11.17 26.26 1.92 11.51 26.28 1.94 11.86 26.30 1.96 12.21 26.32 1.97 12.57 26.34 1.99 12.93 26.36 2.01 13.30 26.38 2.02 13.67 26.40 2.04 14.05 26.42 2.05 14.43 26.44 2.07 14.81 26.46 2.09 15.21 26.48 2.10 15.60 26.50 2.12 16.00 26.52 2.13 16.41 26.54 2.15 16.82 26.56 2.16 17.24 26.58 2.18 17.66 26.60 2.19 18.09 26.62 2.21 18.52 26.64 2.22 18.95 26.66 2.24 19.40 26.68 2.25 19.84 26.70 2.26 20.29 26.72 2.28 20.75 26.74 2.29 21.21 26.76 2.31 21.68 26.78 2.32 22.15 26.80 2.33 22.62 26.82 2.35 23.11 26.84 2.36 23.59 26.86 2.38 24.08 26.88 2.39 24.58 26.90 2.40 25.08 26.92 2.42 25.59 26.94 2.43 26.10 26.96 2.44 26.62 26.98 2.46 27.14 27.00 2.47 27.67 27.02 2.48 28.20 27.04 2.49 28.74 27.06 2.51 29.29 27.08 2.52 29.84 27.10 2.53 30.39 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 48Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach JD: Jurisdictional Ditch [82] Warning: Early inflow requires earlier time span Inflow Area =8.700 ac, Inflow Depth > 6.57" for 25-YR, 24-HR event Inflow =16.26 cfs @ 12.22 hrs, Volume=4.764 af Outflow =15.83 cfs @ 12.32 hrs, Volume=4.764 af, Atten= 3%, Lag= 5.8 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 1.35 fps, Min. Travel Time= 3.2 min Avg. Velocity = 0.50 fps, Avg. Travel Time= 8.7 min Peak Storage= 3,053 cf @ 12.26 hrs, Average Depth at Peak Storage= 1.35' Bank-Full Depth= 2.00', Capacity at Bank-Full= 33.37 cfs 6.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 2.0 '/' Top Width= 14.00' Length= 260.0' Slope= 0.0008 '/' Inlet Invert= 25.40', Outlet Invert= 25.20' ‡ Reach JD: Jurisdictional Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=8.700 ac Avg. Depth=1.35' Max Vel=1.35 fps n=0.030 L=260.0' S=0.0008 '/' Capacity=33.37 cfs 16.26 cfs 15.83 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 49Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach JD: Jurisdictional Ditch Primary Stage-Discharge Discharge (cfs)302520151050 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 50Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach JD: Jurisdictional Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.40 0.00 0.00 25.42 0.10 0.01 25.44 0.16 0.04 25.46 0.21 0.08 25.48 0.25 0.12 25.50 0.29 0.18 25.52 0.32 0.24 25.54 0.36 0.31 25.56 0.39 0.39 25.58 0.42 0.48 25.60 0.45 0.57 25.62 0.47 0.67 25.64 0.50 0.78 25.66 0.53 0.89 25.68 0.55 1.01 25.70 0.57 1.14 25.72 0.60 1.27 25.74 0.62 1.40 25.76 0.64 1.55 25.78 0.66 1.70 25.80 0.68 1.85 25.82 0.70 2.01 25.84 0.72 2.18 25.86 0.74 2.35 25.88 0.76 2.53 25.90 0.78 2.72 25.92 0.79 2.91 25.94 0.81 3.10 25.96 0.83 3.31 25.98 0.85 3.51 26.00 0.86 3.73 26.02 0.88 3.95 26.04 0.89 4.17 26.06 0.91 4.40 26.08 0.93 4.64 26.10 0.94 4.88 26.12 0.96 5.12 26.14 0.97 5.38 26.16 0.99 5.64 26.18 1.00 5.90 26.20 1.01 6.17 26.22 1.03 6.45 26.24 1.04 6.73 26.26 1.06 7.01 26.28 1.07 7.31 26.30 1.08 7.61 26.32 1.10 7.91 26.34 1.11 8.22 26.36 1.12 8.54 26.38 1.14 8.86 26.40 1.15 9.18 26.42 1.16 9.52 26.44 1.17 9.86 26.46 1.19 10.20 26.48 1.20 10.55 26.50 1.21 10.91 26.52 1.22 11.27 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.54 1.23 11.64 26.56 1.24 12.02 26.58 1.26 12.40 26.60 1.27 12.78 26.62 1.28 13.17 26.64 1.29 13.57 26.66 1.30 13.98 26.68 1.31 14.39 26.70 1.32 14.80 26.72 1.34 15.23 26.74 1.35 15.66 26.76 1.36 16.09 26.78 1.37 16.53 26.80 1.38 16.98 26.82 1.39 17.43 26.84 1.40 17.89 26.86 1.41 18.36 26.88 1.42 18.83 26.90 1.43 19.31 26.92 1.44 19.79 26.94 1.45 20.28 26.96 1.46 20.78 26.98 1.47 21.29 27.00 1.48 21.80 27.02 1.49 22.31 27.04 1.50 22.83 27.06 1.51 23.36 27.08 1.52 23.90 27.10 1.53 24.44 27.12 1.54 24.99 27.14 1.55 25.55 27.16 1.56 26.11 27.18 1.57 26.68 27.20 1.58 27.25 27.22 1.59 27.83 27.24 1.60 28.42 27.26 1.60 29.02 27.28 1.61 29.62 27.30 1.62 30.23 27.32 1.63 30.84 27.34 1.64 31.46 27.36 1.65 32.09 27.38 1.66 32.73 27.40 1.67 33.37 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 51Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch [82] Warning: Early inflow requires earlier time span [91] Warning: Storage range exceeded by 2.81' [55] Hint: Peak inflow is 342% of Manning's capacity Inflow Area =43.700 ac, Inflow Depth > 6.37" for 25-YR, 24-HR event Inflow =40.70 cfs @ 16.04 hrs, Volume=23.188 af Outflow =40.60 cfs @ 16.20 hrs, Volume=23.188 af, Atten= 0%, Lag= 9.3 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 0.76 fps, Min. Travel Time= 5.7 min Avg. Velocity = 0.30 fps, Avg. Travel Time= 14.4 min Peak Storage= 13,966 cf @ 16.10 hrs, Average Depth at Peak Storage= 4.81' Bank-Full Depth= 2.00', Capacity at Bank-Full= 11.88 cfs 8.00' x 2.00' deep channel, n= 0.200 Side Slope Z-value= 1.0 '/' Top Width= 12.00' Length= 260.0' Slope= 0.0038 '/' Inlet Invert= 25.00', Outlet Invert= 24.00' Reach WDE: West Drainage Easement Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=43.700 ac Avg. Depth=4.81' Max Vel=0.76 fps n=0.200 L=260.0' S=0.0038 '/' Capacity=11.88 cfs 40.70 cfs 40.60 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 52Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch Primary Stage-Discharge Discharge (cfs)11109876543210 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 53Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach WDE: West Drainage Easement Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.00 0.00 0.00 25.02 0.03 0.01 25.04 0.05 0.02 25.06 0.07 0.03 25.08 0.08 0.05 25.10 0.10 0.08 25.12 0.11 0.11 25.14 0.12 0.14 25.16 0.13 0.17 25.18 0.14 0.21 25.20 0.15 0.25 25.22 0.16 0.29 25.24 0.17 0.34 25.26 0.18 0.39 25.28 0.19 0.44 25.30 0.20 0.49 25.32 0.21 0.55 25.34 0.21 0.61 25.36 0.22 0.67 25.38 0.23 0.73 25.40 0.24 0.80 25.42 0.24 0.86 25.44 0.25 0.93 25.46 0.26 1.00 25.48 0.26 1.08 25.50 0.27 1.15 25.52 0.28 1.23 25.54 0.28 1.31 25.56 0.29 1.39 25.58 0.30 1.48 25.60 0.30 1.56 25.62 0.31 1.65 25.64 0.31 1.74 25.66 0.32 1.83 25.68 0.33 1.92 25.70 0.33 2.02 25.72 0.34 2.12 25.74 0.34 2.22 25.76 0.35 2.32 25.78 0.35 2.42 25.80 0.36 2.52 25.82 0.36 2.63 25.84 0.37 2.74 25.86 0.37 2.85 25.88 0.38 2.96 25.90 0.38 3.07 25.92 0.39 3.19 25.94 0.39 3.30 25.96 0.40 3.42 25.98 0.40 3.54 26.00 0.41 3.67 26.02 0.41 3.79 26.04 0.42 3.92 26.06 0.42 4.04 26.08 0.43 4.17 26.10 0.43 4.30 26.12 0.43 4.43 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.14 0.44 4.57 26.16 0.44 4.70 26.18 0.45 4.84 26.20 0.45 4.98 26.22 0.46 5.12 26.24 0.46 5.26 26.26 0.46 5.41 26.28 0.47 5.55 26.30 0.47 5.70 26.32 0.48 5.85 26.34 0.48 6.00 26.36 0.48 6.15 26.38 0.49 6.31 26.40 0.49 6.46 26.42 0.49 6.62 26.44 0.50 6.78 26.46 0.50 6.94 26.48 0.51 7.10 26.50 0.51 7.27 26.52 0.51 7.43 26.54 0.52 7.60 26.56 0.52 7.77 26.58 0.52 7.94 26.60 0.53 8.11 26.62 0.53 8.28 26.64 0.53 8.46 26.66 0.54 8.63 26.68 0.54 8.81 26.70 0.55 8.99 26.72 0.55 9.17 26.74 0.55 9.36 26.76 0.56 9.54 26.78 0.56 9.73 26.80 0.56 9.92 26.82 0.57 10.11 26.84 0.57 10.30 26.86 0.57 10.49 26.88 0.58 10.68 26.90 0.58 10.88 26.92 0.58 11.08 26.94 0.58 11.28 26.96 0.59 11.48 26.98 0.59 11.68 27.00 0.59 11.88 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 54Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe [57] Hint: Peaked at 38.26' (Flood elevation advised) [63] Warning: Exceeded Reach DOT-1 inflow depth by 11.63' @ 14.50 hrs Inflow Area =13.200 ac, Inflow Depth = 6.95" for 25-YR, 24-HR event Inflow =18.52 cfs @ 14.52 hrs, Volume=7.641 af Outflow =18.52 cfs @ 14.52 hrs, Volume=7.641 af, Atten= 0%, Lag= 0.0 min Primary =18.52 cfs @ 14.52 hrs, Volume=7.641 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 38.26' @ 14.52 hrs Device Routing Invert Outlet Devices #1 Primary 25.01'15.0" x 84.0' long Culvert CPP, mitered to conform to fill, Ke= 0.700 Outlet Invert= 25.00' S= 0.0001 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean Primary OutFlow Max=18.51 cfs @ 14.52 hrs HW=38.24' (Free Discharge) 1=Culvert (Inlet Controls 18.51 cfs @ 15.09 fps) Pond C-1: Driveway Pipe InflowPrimary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Peak Elev=38.26' 15.0" x 84.0' Culvert 18.52 cfs 18.52 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 55Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe Primary Stage-Discharge Discharge (cfs)181614121086420 El e v a t i o n ( f e e t ) 38 37 36 35 34 33 32 31 30 29 28 27 26 Culvert DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 56Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond C-1: Driveway Pipe Elevation (feet) Primary (cfs) 25.01 0.00 25.07 0.00 25.13 0.02 25.19 0.04 25.25 0.09 25.31 0.14 25.37 0.22 25.43 0.31 25.49 0.42 25.55 0.54 25.61 0.67 25.67 0.82 25.73 0.98 25.79 1.15 25.85 1.33 25.91 1.51 25.97 1.71 26.03 1.91 26.09 2.11 26.15 2.32 26.21 2.52 26.27 2.73 26.33 2.93 26.39 3.12 26.45 3.29 26.51 3.46 26.57 3.59 26.63 3.68 26.69 3.71 26.75 3.95 26.81 4.18 26.87 4.40 26.93 4.61 26.99 4.81 27.05 5.00 27.11 5.18 27.17 5.36 27.23 5.53 27.29 5.70 27.35 5.86 27.41 6.02 27.47 6.18 27.53 6.33 27.59 6.47 27.65 6.62 27.71 6.76 27.77 6.89 27.83 7.03 27.89 7.16 27.95 7.29 28.01 7.42 28.07 7.54 28.13 7.67 28.19 7.79 28.25 7.91 28.31 8.02 28.37 8.14 Elevation (feet) Primary (cfs) 28.43 8.26 28.49 8.37 28.55 8.48 28.61 8.59 28.67 8.70 28.73 8.80 28.79 8.91 28.85 9.02 28.91 9.12 28.97 9.22 29.03 9.32 29.09 9.42 29.15 9.52 29.21 9.62 29.27 9.72 29.33 9.81 29.39 9.91 29.45 10.00 29.51 10.10 29.57 10.19 29.63 10.28 29.69 10.37 29.75 10.46 29.81 10.55 29.87 10.64 29.93 10.73 29.99 10.81 30.05 10.90 30.11 10.98 30.17 11.07 30.23 11.15 30.29 11.24 30.35 11.32 30.41 11.39 30.47 11.46 30.53 11.54 30.59 11.61 30.65 11.68 30.71 11.75 30.77 11.81 30.83 11.88 30.89 11.95 30.95 12.02 31.01 12.09 31.07 12.15 31.13 12.22 31.19 12.29 31.25 12.35 31.31 12.42 31.37 12.49 31.43 12.55 31.49 12.62 31.55 12.68 31.61 12.74 31.67 12.81 31.73 12.87 31.79 12.93 Elevation (feet) Primary (cfs) 31.85 13.00 31.91 13.06 31.97 13.12 32.03 13.18 32.09 13.25 32.15 13.31 32.21 13.37 32.27 13.43 32.33 13.49 32.39 13.55 32.45 13.61 32.51 13.67 32.57 13.73 32.63 13.79 32.69 13.85 32.75 13.91 32.81 13.97 32.87 14.02 32.93 14.08 32.99 14.14 33.05 14.20 33.11 14.25 33.17 14.31 33.23 14.37 33.29 14.43 33.35 14.48 33.41 14.54 33.47 14.59 33.53 14.65 33.59 14.71 33.65 14.76 33.71 14.82 33.77 14.87 33.83 14.93 33.89 14.98 33.95 15.03 34.01 15.09 34.07 15.14 34.13 15.20 34.19 15.25 34.25 15.30 34.31 15.36 34.37 15.41 34.43 15.46 34.49 15.51 34.55 15.57 34.61 15.62 34.67 15.67 34.73 15.72 34.79 15.78 34.85 15.83 34.91 15.88 34.97 15.93 35.03 15.98 35.09 16.03 35.15 16.08 35.21 16.13 Elevation (feet) Primary (cfs) 35.27 16.18 35.33 16.23 35.39 16.28 35.45 16.33 35.51 16.38 35.57 16.43 35.63 16.48 35.69 16.53 35.75 16.58 35.81 16.63 35.87 16.68 35.93 16.73 35.99 16.78 36.05 16.83 36.11 16.87 36.17 16.92 36.23 16.97 36.29 17.02 36.35 17.07 36.41 17.11 36.47 17.16 36.53 17.21 36.59 17.26 36.65 17.30 36.71 17.35 36.77 17.40 36.83 17.44 36.89 17.49 36.95 17.54 37.01 17.58 37.07 17.63 37.13 17.68 37.19 17.72 37.25 17.77 37.31 17.81 37.37 17.86 37.43 17.91 37.49 17.95 37.55 18.00 37.61 18.04 37.67 18.09 37.73 18.13 37.79 18.18 37.85 18.22 37.91 18.27 37.97 18.31 38.03 18.36 38.09 18.40 38.15 18.44 38.21 18.49 38.27 18.53 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 57Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=13.200 ac Runoff Depth>8.58"Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Of Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 Runoff=22.78 cfs 9.440 af Runoff Area=42.500 ac Runoff Depth=7.93"Subcatchment Easement: Off-Site Drainage Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 Runoff=50.51 cfs 28.083 af Runoff Area=6.500 ac Runoff Depth=7.80"Subcatchment JD DA: Off-Site Drainage Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 Runoff=15.16 cfs 4.223 af Runoff Area=2.200 ac Runoff Depth>9.28"Subcatchment Lot: Crowatan Lot On Site Drainage Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=89 Runoff=16.53 cfs 1.702 af Runoff Area=1.200 ac Runoff Depth>9.27"Subcatchment WDE DA: On-Site Drainage Tc=5.0 min CN=89 Runoff=12.22 cfs 0.927 af Avg. Depth=1.71' Max Vel=2.34 fps Inflow=22.78 cfs 9.440 afReach DOT-1: NCDOT R/W Ditch n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs Outflow=22.77 cfs 9.440 af Avg. Depth=1.51' Max Vel=1.43 fps Inflow=19.89 cfs 5.925 afReach JD: Jurisdictional Ditch n=0.030 L=260.0' S=0.0008 '/' Capacity=33.37 cfs Outflow=19.45 cfs 5.925 af Avg. Depth=5.81' Max Vel=0.77 fps Inflow=50.85 cfs 29.011 afReach WDE: West Drainage Easement Ditc n=0.200 L=260.0' S=0.0038 '/' Capacity=11.88 cfs Outflow=50.73 cfs 29.010 af Peak Elev=44.71' Inflow=22.77 cfs 9.440 afPond C-1: Driveway Pipe 15.0" x 84.0' Culvert Outflow=22.77 cfs 9.440 af Total Runoff Area = 65.600 ac Runoff Volume = 44.376 af Average Runoff Depth = 8.12" 98.63% Pervious Area = 64.700 ac 1.37% Impervious Area = 0.900 ac DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 58Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Off-Site) Runoff =22.78 cfs @ 14.51 hrs, Volume=9.440 af, Depth> 8.58" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 50-YR, 24-HR Rainfall=10.70" Area (ac) CN Description 6.600 77 Woods, Good, HSG D 0.600 98 Paved parking & roofs 6.000 89 <50% Grass cover, Poor, HSG D 13.200 83 Weighted Average 12.600 Pervious Area 0.600 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, Dense woods n= 0.200 P2= 4.62" 31.6 150 0.0010 0.08 Shallow Concentrated Flow, Dense woods Forest w/Heavy Litter Kv= 2.5 fps 135.0 2,200 0.0010 0.27 3.26 Trap/Vee/Rect Channel Flow, Channel Bot.W=4.00' D=2.00' Z= 1.0 '/' Top.W=8.00' n= 0.200 200.6 2,450 Total Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Off-Site) Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 25 24 2322 21 20 19 18 17 16 1514 13 12 11 10 9 87 6 5 4 3 2 1 0 Type III 24-hr 50-YR 24-HR Rainfall=10.70" Runoff Area=13.200 ac Runoff Volume=9.440 af Runoff Depth>8.58" Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 22.78 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 59Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Easement: Off-Site Drainage Runoff =50.51 cfs @ 16.04 hrs, Volume=28.083 af, Depth= 7.93" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 50-YR, 24-HR Rainfall=10.70" Area (ac) CN Description 34.500 77 Woods, Good, HSG D 0.900 89 Dirt roads, HSG D 6.900 80 >75% Grass cover, Good, HSG D 0.200 98 Paved parking & roofs 42.500 78 Weighted Average 42.300 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 42.2 200 0.0010 0.08 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 231.0 4,200 0.0010 0.30 6.06 Trap/Vee/Rect Channel Flow, Bot.W=8.00' D=2.00' Z= 1.0 '/' Top.W=12.00' n= 0.200 307.2 4,500 Total Subcatchment Easement: Off-Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 55 50 45 40 35 30 25 20 15 10 5 0 Type III 24-hr 50-YR 24-HR Rainfall=10.70" Runoff Area=42.500 ac Runoff Volume=28.083 af Runoff Depth=7.93" Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 50.51 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 60Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment JD DA: Off-Site Drainage Runoff =15.16 cfs @ 13.50 hrs, Volume=4.223 af, Depth= 7.80" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 50-YR, 24-HR Rainfall=10.70" Area (ac) CN Description 6.400 77 Woods, Good, HSG D 0.100 98 Paved parking & roofs 6.500 77 Weighted Average 6.400 Pervious Area 0.100 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 81.8 1,400 0.0010 0.29 5.71 Trap/Vee/Rect Channel Flow, Bot.W=6.00' D=2.00' Z= 2.0 '/' Top.W=14.00' n= 0.200 115.8 1,500 Total Subcatchment JD DA: Off-Site Drainage Runoff Hydrograph Time (hours)48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 50-YR 24-HR Rainfall=10.70" Runoff Area=6.500 ac Runoff Volume=4.223 af Runoff Depth=7.80" Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 15.16 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 61Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Lot: Crowatan Lot On Site Drainage Runoff =16.53 cfs @ 12.21 hrs, Volume=1.702 af, Depth> 9.28" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 50-YR, 24-HR Rainfall=10.70" Area (ac) CN Description 2.200 89 <50% Grass cover, Poor, HSG D 2.200 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.0 100 0.0033 0.24 Sheet Flow, Fallow n= 0.050 P2= 4.62" 9.0 500 0.0033 0.92 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 16.0 600 Total Subcatchment Lot: Crowatan Lot On Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 50-YR 24-HR Rainfall=10.70" Runoff Area=2.200 ac Runoff Volume=1.702 af Runoff Depth>9.28" Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=89 16.53 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 62Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment WDE DA: On-Site Drainage [49] Hint: Tc<2dt may require smaller dt Runoff =12.22 cfs @ 12.07 hrs, Volume=0.927 af, Depth> 9.27" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 50-YR, 24-HR Rainfall=10.70" Area (ac) CN Description 1.200 89 <50% Grass cover, Poor, HSG D 1.200 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 5.0 Direct Entry, Subcatchment WDE DA: On-Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Flo w ( c f s ) 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 50-YR 24-HR Rainfall=10.70" Runoff Area=1.200 ac Runoff Volume=0.927 af Runoff Depth>9.27" Tc=5.0 min CN=89 12.22 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 63Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch Inflow Area =13.200 ac, Inflow Depth > 8.58" for 50-YR, 24-HR event Inflow =22.78 cfs @ 14.51 hrs, Volume=9.440 af Outflow =22.77 cfs @ 14.51 hrs, Volume=9.440 af, Atten= 0%, Lag= 0.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 2.34 fps, Min. Travel Time= 0.3 min Avg. Velocity = 0.98 fps, Avg. Travel Time= 0.8 min Peak Storage= 448 cf @ 14.51 hrs, Average Depth at Peak Storage= 1.71' Bank-Full Depth= 2.00', Capacity at Bank-Full= 30.39 cfs 4.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 1.0 '/' Top Width= 8.00' Length= 46.0' Slope= 0.0020 '/' Inlet Invert= 25.10', Outlet Invert= 25.01' Reach DOT-1: NCDOT R/W Ditch InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=13.200 ac Avg. Depth=1.71' Max Vel=2.34 fps n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs 22.78 cfs22.77 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 64Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch Primary Stage-Discharge Discharge (cfs)302826242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 65Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DOT-1: NCDOT R/W Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.10 0.00 0.00 25.12 0.16 0.01 25.14 0.25 0.04 25.16 0.33 0.08 25.18 0.40 0.13 25.20 0.46 0.19 25.22 0.51 0.25 25.24 0.57 0.33 25.26 0.62 0.41 25.28 0.66 0.50 25.30 0.71 0.60 25.32 0.75 0.70 25.34 0.79 0.81 25.36 0.83 0.92 25.38 0.87 1.04 25.40 0.91 1.17 25.42 0.94 1.30 25.44 0.98 1.44 25.46 1.01 1.58 25.48 1.04 1.73 25.50 1.07 1.89 25.52 1.10 2.05 25.54 1.13 2.22 25.56 1.16 2.39 25.58 1.19 2.56 25.60 1.22 2.75 25.62 1.25 2.93 25.64 1.27 3.12 25.66 1.30 3.32 25.68 1.33 3.52 25.70 1.35 3.73 25.72 1.38 3.94 25.74 1.40 4.16 25.76 1.42 4.38 25.78 1.45 4.61 25.80 1.47 4.84 25.82 1.49 5.08 25.84 1.52 5.32 25.86 1.54 5.56 25.88 1.56 5.82 25.90 1.58 6.07 25.92 1.60 6.33 25.94 1.62 6.60 25.96 1.64 6.87 25.98 1.66 7.15 26.00 1.68 7.43 26.02 1.70 7.71 26.04 1.72 8.00 26.06 1.74 8.30 26.08 1.76 8.60 26.10 1.78 8.90 26.12 1.80 9.21 26.14 1.82 9.52 26.16 1.83 9.84 26.18 1.85 10.17 26.20 1.87 10.49 26.22 1.89 10.83 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.24 1.91 11.17 26.26 1.92 11.51 26.28 1.94 11.86 26.30 1.96 12.21 26.32 1.97 12.57 26.34 1.99 12.93 26.36 2.01 13.30 26.38 2.02 13.67 26.40 2.04 14.05 26.42 2.05 14.43 26.44 2.07 14.81 26.46 2.09 15.21 26.48 2.10 15.60 26.50 2.12 16.00 26.52 2.13 16.41 26.54 2.15 16.82 26.56 2.16 17.24 26.58 2.18 17.66 26.60 2.19 18.09 26.62 2.21 18.52 26.64 2.22 18.95 26.66 2.24 19.40 26.68 2.25 19.84 26.70 2.26 20.29 26.72 2.28 20.75 26.74 2.29 21.21 26.76 2.31 21.68 26.78 2.32 22.15 26.80 2.33 22.62 26.82 2.35 23.11 26.84 2.36 23.59 26.86 2.38 24.08 26.88 2.39 24.58 26.90 2.40 25.08 26.92 2.42 25.59 26.94 2.43 26.10 26.96 2.44 26.62 26.98 2.46 27.14 27.00 2.47 27.67 27.02 2.48 28.20 27.04 2.49 28.74 27.06 2.51 29.29 27.08 2.52 29.84 27.10 2.53 30.39 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 66Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach JD: Jurisdictional Ditch [82] Warning: Early inflow requires earlier time span Inflow Area =8.700 ac, Inflow Depth > 8.17" for 50-YR, 24-HR event Inflow =19.89 cfs @ 12.22 hrs, Volume=5.925 af Outflow =19.45 cfs @ 12.31 hrs, Volume=5.925 af, Atten= 2%, Lag= 5.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 1.43 fps, Min. Travel Time= 3.0 min Avg. Velocity = 0.54 fps, Avg. Travel Time= 8.1 min Peak Storage= 3,529 cf @ 12.26 hrs, Average Depth at Peak Storage= 1.51' Bank-Full Depth= 2.00', Capacity at Bank-Full= 33.37 cfs 6.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 2.0 '/' Top Width= 14.00' Length= 260.0' Slope= 0.0008 '/' Inlet Invert= 25.40', Outlet Invert= 25.20' ‡ Reach JD: Jurisdictional Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=8.700 ac Avg. Depth=1.51' Max Vel=1.43 fps n=0.030 L=260.0' S=0.0008 '/' Capacity=33.37 cfs 19.89 cfs 19.45 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 67Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach JD: Jurisdictional Ditch Primary Stage-Discharge Discharge (cfs)302520151050 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 68Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach JD: Jurisdictional Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.40 0.00 0.00 25.42 0.10 0.01 25.44 0.16 0.04 25.46 0.21 0.08 25.48 0.25 0.12 25.50 0.29 0.18 25.52 0.32 0.24 25.54 0.36 0.31 25.56 0.39 0.39 25.58 0.42 0.48 25.60 0.45 0.57 25.62 0.47 0.67 25.64 0.50 0.78 25.66 0.53 0.89 25.68 0.55 1.01 25.70 0.57 1.14 25.72 0.60 1.27 25.74 0.62 1.40 25.76 0.64 1.55 25.78 0.66 1.70 25.80 0.68 1.85 25.82 0.70 2.01 25.84 0.72 2.18 25.86 0.74 2.35 25.88 0.76 2.53 25.90 0.78 2.72 25.92 0.79 2.91 25.94 0.81 3.10 25.96 0.83 3.31 25.98 0.85 3.51 26.00 0.86 3.73 26.02 0.88 3.95 26.04 0.89 4.17 26.06 0.91 4.40 26.08 0.93 4.64 26.10 0.94 4.88 26.12 0.96 5.12 26.14 0.97 5.38 26.16 0.99 5.64 26.18 1.00 5.90 26.20 1.01 6.17 26.22 1.03 6.45 26.24 1.04 6.73 26.26 1.06 7.01 26.28 1.07 7.31 26.30 1.08 7.61 26.32 1.10 7.91 26.34 1.11 8.22 26.36 1.12 8.54 26.38 1.14 8.86 26.40 1.15 9.18 26.42 1.16 9.52 26.44 1.17 9.86 26.46 1.19 10.20 26.48 1.20 10.55 26.50 1.21 10.91 26.52 1.22 11.27 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.54 1.23 11.64 26.56 1.24 12.02 26.58 1.26 12.40 26.60 1.27 12.78 26.62 1.28 13.17 26.64 1.29 13.57 26.66 1.30 13.98 26.68 1.31 14.39 26.70 1.32 14.80 26.72 1.34 15.23 26.74 1.35 15.66 26.76 1.36 16.09 26.78 1.37 16.53 26.80 1.38 16.98 26.82 1.39 17.43 26.84 1.40 17.89 26.86 1.41 18.36 26.88 1.42 18.83 26.90 1.43 19.31 26.92 1.44 19.79 26.94 1.45 20.28 26.96 1.46 20.78 26.98 1.47 21.29 27.00 1.48 21.80 27.02 1.49 22.31 27.04 1.50 22.83 27.06 1.51 23.36 27.08 1.52 23.90 27.10 1.53 24.44 27.12 1.54 24.99 27.14 1.55 25.55 27.16 1.56 26.11 27.18 1.57 26.68 27.20 1.58 27.25 27.22 1.59 27.83 27.24 1.60 28.42 27.26 1.60 29.02 27.28 1.61 29.62 27.30 1.62 30.23 27.32 1.63 30.84 27.34 1.64 31.46 27.36 1.65 32.09 27.38 1.66 32.73 27.40 1.67 33.37 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 69Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch [82] Warning: Early inflow requires earlier time span [91] Warning: Storage range exceeded by 3.81' [55] Hint: Peak inflow is 428% of Manning's capacity Inflow Area =43.700 ac, Inflow Depth > 7.97" for 50-YR, 24-HR event Inflow =50.85 cfs @ 16.04 hrs, Volume=29.011 af Outflow =50.73 cfs @ 16.18 hrs, Volume=29.010 af, Atten= 0%, Lag= 8.9 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 0.77 fps, Min. Travel Time= 5.6 min Avg. Velocity = 0.32 fps, Avg. Travel Time= 13.5 min Peak Storage= 17,060 cf @ 16.09 hrs, Average Depth at Peak Storage= 5.81' Bank-Full Depth= 2.00', Capacity at Bank-Full= 11.88 cfs 8.00' x 2.00' deep channel, n= 0.200 Side Slope Z-value= 1.0 '/' Top Width= 12.00' Length= 260.0' Slope= 0.0038 '/' Inlet Invert= 25.00', Outlet Invert= 24.00' Reach WDE: West Drainage Easement Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 55 50 45 40 35 30 25 20 15 10 5 0 Inflow Area=43.700 ac Avg. Depth=5.81' Max Vel=0.77 fps n=0.200 L=260.0' S=0.0038 '/' Capacity=11.88 cfs 50.85 cfs 50.73 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 70Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch Primary Stage-Discharge Discharge (cfs)11109876543210 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 71Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach WDE: West Drainage Easement Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.00 0.00 0.00 25.02 0.03 0.01 25.04 0.05 0.02 25.06 0.07 0.03 25.08 0.08 0.05 25.10 0.10 0.08 25.12 0.11 0.11 25.14 0.12 0.14 25.16 0.13 0.17 25.18 0.14 0.21 25.20 0.15 0.25 25.22 0.16 0.29 25.24 0.17 0.34 25.26 0.18 0.39 25.28 0.19 0.44 25.30 0.20 0.49 25.32 0.21 0.55 25.34 0.21 0.61 25.36 0.22 0.67 25.38 0.23 0.73 25.40 0.24 0.80 25.42 0.24 0.86 25.44 0.25 0.93 25.46 0.26 1.00 25.48 0.26 1.08 25.50 0.27 1.15 25.52 0.28 1.23 25.54 0.28 1.31 25.56 0.29 1.39 25.58 0.30 1.48 25.60 0.30 1.56 25.62 0.31 1.65 25.64 0.31 1.74 25.66 0.32 1.83 25.68 0.33 1.92 25.70 0.33 2.02 25.72 0.34 2.12 25.74 0.34 2.22 25.76 0.35 2.32 25.78 0.35 2.42 25.80 0.36 2.52 25.82 0.36 2.63 25.84 0.37 2.74 25.86 0.37 2.85 25.88 0.38 2.96 25.90 0.38 3.07 25.92 0.39 3.19 25.94 0.39 3.30 25.96 0.40 3.42 25.98 0.40 3.54 26.00 0.41 3.67 26.02 0.41 3.79 26.04 0.42 3.92 26.06 0.42 4.04 26.08 0.43 4.17 26.10 0.43 4.30 26.12 0.43 4.43 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.14 0.44 4.57 26.16 0.44 4.70 26.18 0.45 4.84 26.20 0.45 4.98 26.22 0.46 5.12 26.24 0.46 5.26 26.26 0.46 5.41 26.28 0.47 5.55 26.30 0.47 5.70 26.32 0.48 5.85 26.34 0.48 6.00 26.36 0.48 6.15 26.38 0.49 6.31 26.40 0.49 6.46 26.42 0.49 6.62 26.44 0.50 6.78 26.46 0.50 6.94 26.48 0.51 7.10 26.50 0.51 7.27 26.52 0.51 7.43 26.54 0.52 7.60 26.56 0.52 7.77 26.58 0.52 7.94 26.60 0.53 8.11 26.62 0.53 8.28 26.64 0.53 8.46 26.66 0.54 8.63 26.68 0.54 8.81 26.70 0.55 8.99 26.72 0.55 9.17 26.74 0.55 9.36 26.76 0.56 9.54 26.78 0.56 9.73 26.80 0.56 9.92 26.82 0.57 10.11 26.84 0.57 10.30 26.86 0.57 10.49 26.88 0.58 10.68 26.90 0.58 10.88 26.92 0.58 11.08 26.94 0.58 11.28 26.96 0.59 11.48 26.98 0.59 11.68 27.00 0.59 11.88 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 72Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe [57] Hint: Peaked at 44.71' (Flood elevation advised) [63] Warning: Exceeded Reach DOT-1 inflow depth by 17.90' @ 14.50 hrs Inflow Area =13.200 ac, Inflow Depth > 8.58" for 50-YR, 24-HR event Inflow =22.77 cfs @ 14.51 hrs, Volume=9.440 af Outflow =22.77 cfs @ 14.51 hrs, Volume=9.440 af, Atten= 0%, Lag= 0.0 min Primary =22.77 cfs @ 14.51 hrs, Volume=9.440 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 44.71' @ 14.51 hrs Device Routing Invert Outlet Devices #1 Primary 25.01'15.0" x 84.0' long Culvert CPP, mitered to conform to fill, Ke= 0.700 Outlet Invert= 25.00' S= 0.0001 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean Primary OutFlow Max=22.76 cfs @ 14.51 hrs HW=44.69' (Free Discharge) 1=Culvert (Inlet Controls 22.76 cfs @ 18.55 fps) Pond C-1: Driveway Pipe InflowPrimary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=13.200 ac Peak Elev=44.71' 15.0" x 84.0' Culvert 22.77 cfs 22.77 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 73Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe Primary Stage-Discharge Discharge (cfs)2220181614121086420 El e v a t i o n ( f e e t ) 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 Culvert DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 74Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond C-1: Driveway Pipe Elevation (feet) Primary (cfs) 25.01 0.00 25.21 0.06 25.41 0.28 25.61 0.67 25.81 1.21 26.01 1.84 26.21 2.52 26.41 3.18 26.61 3.66 26.81 4.18 27.01 4.87 27.21 5.48 27.41 6.02 27.61 6.52 27.81 6.98 28.01 7.42 28.21 7.83 28.41 8.22 28.61 8.59 28.81 8.95 29.01 9.29 29.21 9.62 29.41 9.94 29.61 10.25 29.81 10.55 30.01 10.84 30.21 11.13 30.41 11.39 30.61 11.63 30.81 11.86 31.01 12.09 31.21 12.31 31.41 12.53 31.61 12.74 31.81 12.96 32.01 13.16 32.21 13.37 32.41 13.57 32.61 13.77 32.81 13.97 33.01 14.16 33.21 14.35 33.41 14.54 33.61 14.72 33.81 14.91 34.01 15.09 34.21 15.27 34.41 15.44 34.61 15.62 34.81 15.79 35.01 15.96 35.21 16.13 35.41 16.30 35.61 16.47 35.81 16.63 36.01 16.79 36.21 16.95 Elevation (feet) Primary (cfs) 36.41 17.11 36.61 17.27 36.81 17.43 37.01 17.58 37.21 17.74 37.41 17.89 37.61 18.04 37.81 18.19 38.01 18.34 38.21 18.49 38.41 18.63 38.61 18.78 38.81 18.92 39.01 19.07 39.21 19.21 39.41 19.35 39.61 19.49 39.81 19.63 40.01 19.77 40.21 19.90 40.41 20.04 40.61 20.18 40.81 20.31 41.01 20.44 41.21 20.58 41.41 20.71 41.61 20.84 41.81 20.97 42.01 21.10 42.21 21.23 42.41 21.35 42.61 21.48 42.81 21.61 43.01 21.73 43.21 21.86 43.41 21.98 43.61 22.10 43.81 22.23 44.01 22.35 44.21 22.47 44.41 22.59 44.61 22.71 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 75Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=13.200 ac Runoff Depth>10.34"Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (O Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 Runoff=27.29 cfs 11.372 af Runoff Area=42.500 ac Runoff Depth=9.65"Subcatchment Easement: Off-Site Drainage Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 Runoff=61.31 cfs 34.193 af Runoff Area=6.500 ac Runoff Depth=9.51"Subcatchment JD DA: Off-Site Drainage Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 Runoff=18.39 cfs 5.154 af Runoff Area=2.200 ac Runoff Depth>11.03"Subcatchment Lot: Crowatan Lot On Site Drainage Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=89 Runoff=19.49 cfs 2.021 af Runoff Area=1.200 ac Runoff Depth>11.01"Subcatchment WDE DA: On-Site Drainage Tc=5.0 min CN=89 Runoff=14.41 cfs 1.101 af Avg. Depth=1.89' Max Vel=2.46 fps Inflow=27.29 cfs 11.372 afReach DOT-1: NCDOT R/W Ditch n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs Outflow=27.28 cfs 11.372 af Avg. Depth=1.66' Max Vel=1.51 fps Inflow=23.75 cfs 7.175 afReach JD: Jurisdictional Ditch n=0.030 L=260.0' S=0.0008 '/' Capacity=33.37 cfs Outflow=23.25 cfs 7.175 af Avg. Depth=6.87' Max Vel=0.79 fps Inflow=61.70 cfs 35.294 afReach WDE: West Drainage Easement Ditc n=0.200 L=260.0' S=0.0038 '/' Capacity=11.88 cfs Outflow=61.57 cfs 35.294 af Peak Elev=53.02' Inflow=27.28 cfs 11.372 afPond C-1: Driveway Pipe 15.0" x 84.0' Culvert Outflow=27.28 cfs 11.372 af Total Runoff Area = 65.600 ac Runoff Volume = 53.842 af Average Runoff Depth = 9.85" 98.63% Pervious Area = 64.700 ac 1.37% Impervious Area = 0.900 ac DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 76Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Off-Site) Runoff =27.29 cfs @ 14.50 hrs, Volume=11.372 af, Depth>10.34" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR, 24-HR Rainfall=12.50" Area (ac) CN Description 6.600 77 Woods, Good, HSG D 0.600 98 Paved parking & roofs 6.000 89 <50% Grass cover, Poor, HSG D 13.200 83 Weighted Average 12.600 Pervious Area 0.600 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, Dense woods n= 0.200 P2= 4.62" 31.6 150 0.0010 0.08 Shallow Concentrated Flow, Dense woods Forest w/Heavy Litter Kv= 2.5 fps 135.0 2,200 0.0010 0.27 3.26 Trap/Vee/Rect Channel Flow, Channel Bot.W=4.00' D=2.00' Z= 1.0 '/' Top.W=8.00' n= 0.200 200.6 2,450 Total Subcatchment DOT DA: NCDOT R/W Ditch Drainage Area (Off-Site) Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type III 24-hr 100-YR 24-HR Rainfall=12.50" Runoff Area=13.200 ac Runoff Volume=11.372 af Runoff Depth>10.34" Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 27.29 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 77Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Easement: Off-Site Drainage Runoff =61.31 cfs @ 16.03 hrs, Volume=34.193 af, Depth= 9.65" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR, 24-HR Rainfall=12.50" Area (ac) CN Description 34.500 77 Woods, Good, HSG D 0.900 89 Dirt roads, HSG D 6.900 80 >75% Grass cover, Good, HSG D 0.200 98 Paved parking & roofs 42.500 78 Weighted Average 42.300 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 42.2 200 0.0010 0.08 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 231.0 4,200 0.0010 0.30 6.06 Trap/Vee/Rect Channel Flow, Bot.W=8.00' D=2.00' Z= 1.0 '/' Top.W=12.00' n= 0.200 307.2 4,500 Total Subcatchment Easement: Off-Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Type III 24-hr 100-YR 24-HR Rainfall=12.50" Runoff Area=42.500 ac Runoff Volume=34.193 af Runoff Depth=9.65" Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 61.31 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 78Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment JD DA: Off-Site Drainage Runoff =18.39 cfs @ 13.50 hrs, Volume=5.154 af, Depth= 9.51" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR, 24-HR Rainfall=12.50" Area (ac) CN Description 6.400 77 Woods, Good, HSG D 0.100 98 Paved parking & roofs 6.500 77 Weighted Average 6.400 Pervious Area 0.100 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 81.8 1,400 0.0010 0.29 5.71 Trap/Vee/Rect Channel Flow, Bot.W=6.00' D=2.00' Z= 2.0 '/' Top.W=14.00' n= 0.200 115.8 1,500 Total Subcatchment JD DA: Off-Site Drainage Runoff Hydrograph Time (hours)48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 100-YR 24-HR Rainfall=12.50" Runoff Area=6.500 ac Runoff Volume=5.154 af Runoff Depth=9.51" Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 18.39 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 79Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Lot: Crowatan Lot On Site Drainage Runoff =19.49 cfs @ 12.21 hrs, Volume=2.021 af, Depth>11.03" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR, 24-HR Rainfall=12.50" Area (ac) CN Description 2.200 89 <50% Grass cover, Poor, HSG D 2.200 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.0 100 0.0033 0.24 Sheet Flow, Fallow n= 0.050 P2= 4.62" 9.0 500 0.0033 0.92 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 16.0 600 Total Subcatchment Lot: Crowatan Lot On Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 100-YR 24-HR Rainfall=12.50" Runoff Area=2.200 ac Runoff Volume=2.021 af Runoff Depth>11.03" Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=89 19.49 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 80Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment WDE DA: On-Site Drainage [49] Hint: Tc<2dt may require smaller dt Runoff =14.41 cfs @ 12.07 hrs, Volume=1.101 af, Depth>11.01" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR, 24-HR Rainfall=12.50" Area (ac) CN Description 1.200 89 <50% Grass cover, Poor, HSG D 1.200 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 5.0 Direct Entry, Subcatchment WDE DA: On-Site Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Flo w ( c f s ) 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 100-YR 24-HR Rainfall=12.50" Runoff Area=1.200 ac Runoff Volume=1.101 af Runoff Depth>11.01" Tc=5.0 min CN=89 14.41 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 81Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch Inflow Area =13.200 ac, Inflow Depth > 10.34" for 100-YR, 24-HR event Inflow =27.29 cfs @ 14.50 hrs, Volume=11.372 af Outflow =27.28 cfs @ 14.51 hrs, Volume=11.372 af, Atten= 0%, Lag= 0.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 2.46 fps, Min. Travel Time= 0.3 min Avg. Velocity = 1.05 fps, Avg. Travel Time= 0.7 min Peak Storage= 511 cf @ 14.51 hrs, Average Depth at Peak Storage= 1.89' Bank-Full Depth= 2.00', Capacity at Bank-Full= 30.39 cfs 4.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 1.0 '/' Top Width= 8.00' Length= 46.0' Slope= 0.0020 '/' Inlet Invert= 25.10', Outlet Invert= 25.01' Reach DOT-1: NCDOT R/W Ditch InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=13.200 ac Avg. Depth=1.89' Max Vel=2.46 fps n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs 27.29 cfs27.28 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 82Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch Primary Stage-Discharge Discharge (cfs)302826242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 83Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DOT-1: NCDOT R/W Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.10 0.00 0.00 25.12 0.16 0.01 25.14 0.25 0.04 25.16 0.33 0.08 25.18 0.40 0.13 25.20 0.46 0.19 25.22 0.51 0.25 25.24 0.57 0.33 25.26 0.62 0.41 25.28 0.66 0.50 25.30 0.71 0.60 25.32 0.75 0.70 25.34 0.79 0.81 25.36 0.83 0.92 25.38 0.87 1.04 25.40 0.91 1.17 25.42 0.94 1.30 25.44 0.98 1.44 25.46 1.01 1.58 25.48 1.04 1.73 25.50 1.07 1.89 25.52 1.10 2.05 25.54 1.13 2.22 25.56 1.16 2.39 25.58 1.19 2.56 25.60 1.22 2.75 25.62 1.25 2.93 25.64 1.27 3.12 25.66 1.30 3.32 25.68 1.33 3.52 25.70 1.35 3.73 25.72 1.38 3.94 25.74 1.40 4.16 25.76 1.42 4.38 25.78 1.45 4.61 25.80 1.47 4.84 25.82 1.49 5.08 25.84 1.52 5.32 25.86 1.54 5.56 25.88 1.56 5.82 25.90 1.58 6.07 25.92 1.60 6.33 25.94 1.62 6.60 25.96 1.64 6.87 25.98 1.66 7.15 26.00 1.68 7.43 26.02 1.70 7.71 26.04 1.72 8.00 26.06 1.74 8.30 26.08 1.76 8.60 26.10 1.78 8.90 26.12 1.80 9.21 26.14 1.82 9.52 26.16 1.83 9.84 26.18 1.85 10.17 26.20 1.87 10.49 26.22 1.89 10.83 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.24 1.91 11.17 26.26 1.92 11.51 26.28 1.94 11.86 26.30 1.96 12.21 26.32 1.97 12.57 26.34 1.99 12.93 26.36 2.01 13.30 26.38 2.02 13.67 26.40 2.04 14.05 26.42 2.05 14.43 26.44 2.07 14.81 26.46 2.09 15.21 26.48 2.10 15.60 26.50 2.12 16.00 26.52 2.13 16.41 26.54 2.15 16.82 26.56 2.16 17.24 26.58 2.18 17.66 26.60 2.19 18.09 26.62 2.21 18.52 26.64 2.22 18.95 26.66 2.24 19.40 26.68 2.25 19.84 26.70 2.26 20.29 26.72 2.28 20.75 26.74 2.29 21.21 26.76 2.31 21.68 26.78 2.32 22.15 26.80 2.33 22.62 26.82 2.35 23.11 26.84 2.36 23.59 26.86 2.38 24.08 26.88 2.39 24.58 26.90 2.40 25.08 26.92 2.42 25.59 26.94 2.43 26.10 26.96 2.44 26.62 26.98 2.46 27.14 27.00 2.47 27.67 27.02 2.48 28.20 27.04 2.49 28.74 27.06 2.51 29.29 27.08 2.52 29.84 27.10 2.53 30.39 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 84Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach JD: Jurisdictional Ditch [82] Warning: Early inflow requires earlier time span Inflow Area =8.700 ac, Inflow Depth > 9.90" for 100-YR, 24-HR event Inflow =23.75 cfs @ 12.22 hrs, Volume=7.175 af Outflow =23.25 cfs @ 12.31 hrs, Volume=7.175 af, Atten= 2%, Lag= 5.3 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 1.51 fps, Min. Travel Time= 2.9 min Avg. Velocity = 0.57 fps, Avg. Travel Time= 7.6 min Peak Storage= 4,012 cf @ 12.26 hrs, Average Depth at Peak Storage= 1.66' Bank-Full Depth= 2.00', Capacity at Bank-Full= 33.37 cfs 6.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 2.0 '/' Top Width= 14.00' Length= 260.0' Slope= 0.0008 '/' Inlet Invert= 25.40', Outlet Invert= 25.20' ‡ Reach JD: Jurisdictional Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=8.700 ac Avg. Depth=1.66' Max Vel=1.51 fps n=0.030 L=260.0' S=0.0008 '/' Capacity=33.37 cfs 23.75 cfs 23.25 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 85Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach JD: Jurisdictional Ditch Primary Stage-Discharge Discharge (cfs)302520151050 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 86Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach JD: Jurisdictional Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.40 0.00 0.00 25.42 0.10 0.01 25.44 0.16 0.04 25.46 0.21 0.08 25.48 0.25 0.12 25.50 0.29 0.18 25.52 0.32 0.24 25.54 0.36 0.31 25.56 0.39 0.39 25.58 0.42 0.48 25.60 0.45 0.57 25.62 0.47 0.67 25.64 0.50 0.78 25.66 0.53 0.89 25.68 0.55 1.01 25.70 0.57 1.14 25.72 0.60 1.27 25.74 0.62 1.40 25.76 0.64 1.55 25.78 0.66 1.70 25.80 0.68 1.85 25.82 0.70 2.01 25.84 0.72 2.18 25.86 0.74 2.35 25.88 0.76 2.53 25.90 0.78 2.72 25.92 0.79 2.91 25.94 0.81 3.10 25.96 0.83 3.31 25.98 0.85 3.51 26.00 0.86 3.73 26.02 0.88 3.95 26.04 0.89 4.17 26.06 0.91 4.40 26.08 0.93 4.64 26.10 0.94 4.88 26.12 0.96 5.12 26.14 0.97 5.38 26.16 0.99 5.64 26.18 1.00 5.90 26.20 1.01 6.17 26.22 1.03 6.45 26.24 1.04 6.73 26.26 1.06 7.01 26.28 1.07 7.31 26.30 1.08 7.61 26.32 1.10 7.91 26.34 1.11 8.22 26.36 1.12 8.54 26.38 1.14 8.86 26.40 1.15 9.18 26.42 1.16 9.52 26.44 1.17 9.86 26.46 1.19 10.20 26.48 1.20 10.55 26.50 1.21 10.91 26.52 1.22 11.27 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.54 1.23 11.64 26.56 1.24 12.02 26.58 1.26 12.40 26.60 1.27 12.78 26.62 1.28 13.17 26.64 1.29 13.57 26.66 1.30 13.98 26.68 1.31 14.39 26.70 1.32 14.80 26.72 1.34 15.23 26.74 1.35 15.66 26.76 1.36 16.09 26.78 1.37 16.53 26.80 1.38 16.98 26.82 1.39 17.43 26.84 1.40 17.89 26.86 1.41 18.36 26.88 1.42 18.83 26.90 1.43 19.31 26.92 1.44 19.79 26.94 1.45 20.28 26.96 1.46 20.78 26.98 1.47 21.29 27.00 1.48 21.80 27.02 1.49 22.31 27.04 1.50 22.83 27.06 1.51 23.36 27.08 1.52 23.90 27.10 1.53 24.44 27.12 1.54 24.99 27.14 1.55 25.55 27.16 1.56 26.11 27.18 1.57 26.68 27.20 1.58 27.25 27.22 1.59 27.83 27.24 1.60 28.42 27.26 1.60 29.02 27.28 1.61 29.62 27.30 1.62 30.23 27.32 1.63 30.84 27.34 1.64 31.46 27.36 1.65 32.09 27.38 1.66 32.73 27.40 1.67 33.37 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 87Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch [82] Warning: Early inflow requires earlier time span [91] Warning: Storage range exceeded by 4.87' [55] Hint: Peak inflow is 519% of Manning's capacity Inflow Area =43.700 ac, Inflow Depth > 9.69" for 100-YR, 24-HR event Inflow =61.70 cfs @ 16.03 hrs, Volume=35.294 af Outflow =61.57 cfs @ 16.17 hrs, Volume=35.294 af, Atten= 0%, Lag= 8.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 0.79 fps, Min. Travel Time= 5.5 min Avg. Velocity = 0.34 fps, Avg. Travel Time= 12.8 min Peak Storage= 20,370 cf @ 16.08 hrs, Average Depth at Peak Storage= 6.87' Bank-Full Depth= 2.00', Capacity at Bank-Full= 11.88 cfs 8.00' x 2.00' deep channel, n= 0.200 Side Slope Z-value= 1.0 '/' Top Width= 12.00' Length= 260.0' Slope= 0.0038 '/' Inlet Invert= 25.00', Outlet Invert= 24.00' Reach WDE: West Drainage Easement Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Inflow Area=43.700 ac Avg. Depth=6.87' Max Vel=0.79 fps n=0.200 L=260.0' S=0.0038 '/' Capacity=11.88 cfs 61.70 cfs 61.57 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 88Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch Primary Stage-Discharge Discharge (cfs)11109876543210 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 89Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach WDE: West Drainage Easement Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.00 0.00 0.00 25.02 0.03 0.01 25.04 0.05 0.02 25.06 0.07 0.03 25.08 0.08 0.05 25.10 0.10 0.08 25.12 0.11 0.11 25.14 0.12 0.14 25.16 0.13 0.17 25.18 0.14 0.21 25.20 0.15 0.25 25.22 0.16 0.29 25.24 0.17 0.34 25.26 0.18 0.39 25.28 0.19 0.44 25.30 0.20 0.49 25.32 0.21 0.55 25.34 0.21 0.61 25.36 0.22 0.67 25.38 0.23 0.73 25.40 0.24 0.80 25.42 0.24 0.86 25.44 0.25 0.93 25.46 0.26 1.00 25.48 0.26 1.08 25.50 0.27 1.15 25.52 0.28 1.23 25.54 0.28 1.31 25.56 0.29 1.39 25.58 0.30 1.48 25.60 0.30 1.56 25.62 0.31 1.65 25.64 0.31 1.74 25.66 0.32 1.83 25.68 0.33 1.92 25.70 0.33 2.02 25.72 0.34 2.12 25.74 0.34 2.22 25.76 0.35 2.32 25.78 0.35 2.42 25.80 0.36 2.52 25.82 0.36 2.63 25.84 0.37 2.74 25.86 0.37 2.85 25.88 0.38 2.96 25.90 0.38 3.07 25.92 0.39 3.19 25.94 0.39 3.30 25.96 0.40 3.42 25.98 0.40 3.54 26.00 0.41 3.67 26.02 0.41 3.79 26.04 0.42 3.92 26.06 0.42 4.04 26.08 0.43 4.17 26.10 0.43 4.30 26.12 0.43 4.43 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.14 0.44 4.57 26.16 0.44 4.70 26.18 0.45 4.84 26.20 0.45 4.98 26.22 0.46 5.12 26.24 0.46 5.26 26.26 0.46 5.41 26.28 0.47 5.55 26.30 0.47 5.70 26.32 0.48 5.85 26.34 0.48 6.00 26.36 0.48 6.15 26.38 0.49 6.31 26.40 0.49 6.46 26.42 0.49 6.62 26.44 0.50 6.78 26.46 0.50 6.94 26.48 0.51 7.10 26.50 0.51 7.27 26.52 0.51 7.43 26.54 0.52 7.60 26.56 0.52 7.77 26.58 0.52 7.94 26.60 0.53 8.11 26.62 0.53 8.28 26.64 0.53 8.46 26.66 0.54 8.63 26.68 0.54 8.81 26.70 0.55 8.99 26.72 0.55 9.17 26.74 0.55 9.36 26.76 0.56 9.54 26.78 0.56 9.73 26.80 0.56 9.92 26.82 0.57 10.11 26.84 0.57 10.30 26.86 0.57 10.49 26.88 0.58 10.68 26.90 0.58 10.88 26.92 0.58 11.08 26.94 0.58 11.28 26.96 0.59 11.48 26.98 0.59 11.68 27.00 0.59 11.88 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 90Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe [57] Hint: Peaked at 53.02' (Flood elevation advised) [63] Warning: Exceeded Reach DOT-1 inflow depth by 26.03' @ 14.50 hrs Inflow Area =13.200 ac, Inflow Depth > 10.34" for 100-YR, 24-HR event Inflow =27.28 cfs @ 14.51 hrs, Volume=11.372 af Outflow =27.28 cfs @ 14.51 hrs, Volume=11.372 af, Atten= 0%, Lag= 0.0 min Primary =27.28 cfs @ 14.51 hrs, Volume=11.372 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 53.02' @ 14.51 hrs Device Routing Invert Outlet Devices #1 Primary 25.01'15.0" x 84.0' long Culvert CPP, mitered to conform to fill, Ke= 0.700 Outlet Invert= 25.00' S= 0.0001 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean Primary OutFlow Max=27.27 cfs @ 14.51 hrs HW=53.00' (Free Discharge) 1=Culvert (Inlet Controls 27.27 cfs @ 22.22 fps) Pond C-1: Driveway Pipe InflowPrimary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=13.200 ac Peak Elev=53.02' 15.0" x 84.0' Culvert 27.28 cfs 27.28 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 91Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe Primary Stage-Discharge Discharge (cfs)26242220181614121086420 El e v a t i o n ( f e e t ) 52 50 48 46 44 42 40 38 36 34 32 30 28 26 Culvert DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Pre-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Pre-Con_SRR-23-1_RTC2 Page 92Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond C-1: Driveway Pipe Elevation (feet) Primary (cfs) 25.01 0.00 25.31 0.14 25.61 0.67 25.91 1.51 26.21 2.52 26.51 3.46 26.81 4.18 27.11 5.18 27.41 6.02 27.71 6.76 28.01 7.42 28.31 8.02 28.61 8.59 28.91 9.12 29.21 9.62 29.51 10.10 29.81 10.55 30.11 10.98 30.41 11.39 30.71 11.75 31.01 12.09 31.31 12.42 31.61 12.74 31.91 13.06 32.21 13.37 32.51 13.67 32.81 13.97 33.11 14.25 33.41 14.54 33.71 14.82 34.01 15.09 34.31 15.36 34.61 15.62 34.91 15.88 35.21 16.13 35.51 16.38 35.81 16.63 36.11 16.87 36.41 17.11 36.71 17.35 37.01 17.58 37.31 17.81 37.61 18.04 37.91 18.27 38.21 18.49 38.51 18.71 38.81 18.92 39.11 19.14 39.41 19.35 39.71 19.56 40.01 19.77 40.31 19.97 40.61 20.18 40.91 20.38 41.21 20.58 41.51 20.77 41.81 20.97 Elevation (feet) Primary (cfs) 42.11 21.16 42.41 21.35 42.71 21.54 43.01 21.73 43.31 21.92 43.61 22.10 43.91 22.29 44.21 22.47 44.51 22.65 44.81 22.83 45.11 23.01 45.41 23.18 45.71 23.36 46.01 23.53 46.31 23.71 46.61 23.88 46.91 24.05 47.21 24.22 47.51 24.38 47.81 24.55 48.11 24.72 48.41 24.88 48.71 25.04 49.01 25.21 49.31 25.37 49.61 25.53 49.91 25.69 50.21 25.85 50.51 26.00 50.81 26.16 51.11 26.32 51.41 26.47 51.71 26.62 52.01 26.78 52.31 26.93 52.61 27.08 52.91 27.23 53.21 27.38 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DA-1 Proposed Drainage Channel Drainage Area DOT DA Existing DOT R/W Ditch Drainage Area (Off-Site) Easement West Drainage Easement Drainage Lot Crowatan Lot DC-1 Drainage Channel DOT-1 NCDOT R/W Ditch (Existing) WDE West Drainage Easement Ditch C-1CB Driveway Pipe SB-1 Basin 1 Drainage Diagram for SRR Crowatan Rd Post Con._JCL_Apr_RTC Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcat Reach Pond Link Post-Construction Conditions DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 2Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres)CN Description (subcats) 49.100 77 Woods, Good, HSG D (DA-1,DOT DA,Easement) 6.900 80 >75% Grass cover, Good, HSG D (Easement) 6.000 89 <50% Grass cover, Poor, HSG D (DOT DA) 0.900 89 Dirt roads, HSG D (Easement) 2.800 90 Gravel roads, HSG D (Lot) 0.800 98 Paved parking & roofs (DOT DA,Easement) 66.500 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 3Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=6.800 ac Runoff Depth=2.31"Subcatchment DA-1: Proposed Drainage Channel Drainage Ar Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 Runoff=4.67 cfs 1.308 af Runoff Area=13.200 ac Runoff Depth=2.83"Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Ar Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 Runoff=7.58 cfs 3.116 af Runoff Area=43.700 ac Runoff Depth=2.39"Subcatchment Easement: West Drainage Easement Drainage Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 Runoff=15.48 cfs 8.712 af Runoff Area=2.800 ac Runoff Depth>3.51"Subcatchment Lot: Crowatan Lot Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=90 Runoff=8.27 cfs 0.819 af Avg. Depth=0.90' Max Vel=0.91 fps Inflow=4.67 cfs 1.308 afReach DC-1: Drainage Channel n=0.030 L=440.0' S=0.0007 '/' Capacity=25.56 cfs Outflow=4.63 cfs 1.308 af Avg. Depth=0.91' Max Vel=1.69 fps Inflow=7.58 cfs 3.116 afReach DOT-1: NCDOT R/W Ditch (Existing) n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs Outflow=7.58 cfs 3.116 af Avg. Depth=7.58' Max Vel=0.20 fps Inflow=17.43 cfs 10.757 afReach WDE: West Drainage Easement Ditc n=0.800 L=260.0' S=0.0038 '/' Capacity=2.97 cfs Outflow=17.20 cfs 10.747 af Peak Elev=26.74' Inflow=7.58 cfs 3.116 afPond C-1: Driveway Pipe 24.0" x 84.0' Culvert Outflow=7.58 cfs 3.116 af Peak Elev=26.72' Storage=16,945 cf Inflow=8.27 cfs 0.819 afPond SB-1: Basin 1 Primary=3.48 cfs 0.737 af Secondary=0.00 cfs 0.000 af Outflow=3.48 cfs 0.737 af Total Runoff Area = 66.500 ac Runoff Volume = 13.955 af Average Runoff Depth = 2.52" 98.80% Pervious Area = 65.700 ac 1.20% Impervious Area = 0.800 ac DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 4Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DA-1: Proposed Drainage Channel Drainage Area Runoff =4.67 cfs @ 13.53 hrs, Volume=1.308 af, Depth= 2.31" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR, 24-HR Rainfall=4.62" Area (ac) CN Description 6.800 77 Woods, Good, HSG D 6.800 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 81.8 1,400 0.0010 0.29 5.71 Trap/Vee/Rect Channel Flow, Bot.W=6.00' D=2.00' Z= 2.0 '/' Top.W=14.00' n= 0.200 115.8 1,500 Total Subcatchment DA-1: Proposed Drainage Channel Drainage Area Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 5 4 3 2 1 0 Type III 24-hr 2-YR 24-HR Rainfall=4.62" Runoff Area=6.800 ac Runoff Volume=1.308 af Runoff Depth=2.31" Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 4.67 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 5Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Area (Off-Site) Runoff =7.58 cfs @ 14.55 hrs, Volume=3.116 af, Depth= 2.83" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR, 24-HR Rainfall=4.62" Area (ac) CN Description 6.600 77 Woods, Good, HSG D 0.600 98 Paved parking & roofs 6.000 89 <50% Grass cover, Poor, HSG D 13.200 83 Weighted Average 12.600 Pervious Area 0.600 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, Dense woods n= 0.200 P2= 4.62" 31.6 150 0.0010 0.08 Shallow Concentrated Flow, Dense woods Forest w/Heavy Litter Kv= 2.5 fps 135.0 2,200 0.0010 0.27 3.26 Trap/Vee/Rect Channel Flow, Bot.W=4.00' D=2.00' Z= 1.0 '/' Top.W=8.00' n= 0.200 200.6 2,450 Total Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Area (Off-Site) Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 8 7 6 5 4 3 2 1 0 Type III 24-hr 2-YR 24-HR Rainfall=4.62" Runoff Area=13.200 ac Runoff Volume=3.116 af Runoff Depth=2.83" Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 7.58 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 6Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Easement: West Drainage Easement Drainage Runoff =15.48 cfs @ 16.07 hrs, Volume=8.712 af, Depth= 2.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR, 24-HR Rainfall=4.62" Area (ac) CN Description 35.700 77 Woods, Good, HSG D 0.900 89 Dirt roads, HSG D 6.900 80 >75% Grass cover, Good, HSG D 0.200 98 Paved parking & roofs 43.700 78 Weighted Average 43.500 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 42.2 200 0.0010 0.08 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 231.0 4,200 0.0010 0.30 6.06 Trap/Vee/Rect Channel Flow, Bot.W=8.00' D=2.00' Z= 1.0 '/' Top.W=12.00' n= 0.200 307.2 4,500 Total Subcatchment Easement: West Drainage Easement Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 2-YR 24-HR Rainfall=4.62" Runoff Area=43.700 ac Runoff Volume=8.712 af Runoff Depth=2.39" Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 15.48 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 7Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Lot: Crowatan Lot Runoff =8.27 cfs @ 12.21 hrs, Volume=0.819 af, Depth> 3.51" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 2-YR, 24-HR Rainfall=4.62" Area (ac) CN Description 2.800 90 Gravel roads, HSG D 2.800 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.0 100 0.0033 0.24 Sheet Flow, Fallow n= 0.050 P2= 4.62" 9.0 500 0.0033 0.92 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 16.0 600 Total Subcatchment Lot: Crowatan Lot Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 2-YR 24-HR Rainfall=4.62" Runoff Area=2.800 ac Runoff Volume=0.819 af Runoff Depth>3.51" Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=90 8.27 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 8Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DC-1: Drainage Channel Inflow Area =6.800 ac, Inflow Depth = 2.31" for 2-YR, 24-HR event Inflow =4.67 cfs @ 13.53 hrs, Volume=1.308 af Outflow =4.63 cfs @ 13.79 hrs, Volume=1.308 af, Atten= 1%, Lag= 15.8 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 0.91 fps, Min. Travel Time= 8.1 min Avg. Velocity = 0.33 fps, Avg. Travel Time= 22.1 min Peak Storage= 2,242 cf @ 13.65 hrs, Average Depth at Peak Storage= 0.90' Bank-Full Depth= 2.00', Capacity at Bank-Full= 25.56 cfs 3.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 3.0 '/' Top Width= 15.00' Length= 440.0' Slope= 0.0007 '/' Inlet Invert= 25.40', Outlet Invert= 25.10' ‡ Reach DC-1: Drainage Channel InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 5 4 3 2 1 0 Inflow Area=6.800 ac Avg. Depth=0.90' Max Vel=0.91 fps n=0.030 L=440.0' S=0.0007 '/' Capacity=25.56 cfs 4.67 cfs 4.63 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 9Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DC-1: Drainage Channel Primary Stage-Discharge Discharge (cfs)242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 10Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DC-1: Drainage Channel Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.40 0.00 0.00 25.42 0.09 0.01 25.44 0.15 0.02 25.46 0.19 0.04 25.48 0.23 0.06 25.50 0.26 0.09 25.52 0.29 0.12 25.54 0.32 0.15 25.56 0.35 0.19 25.58 0.37 0.24 25.60 0.40 0.28 25.62 0.42 0.34 25.64 0.44 0.39 25.66 0.46 0.45 25.68 0.48 0.52 25.70 0.50 0.58 25.72 0.52 0.65 25.74 0.53 0.73 25.76 0.55 0.81 25.78 0.57 0.89 25.80 0.58 0.98 25.82 0.60 1.07 25.84 0.62 1.17 25.86 0.63 1.27 25.88 0.65 1.38 25.90 0.66 1.49 25.92 0.68 1.60 25.94 0.69 1.72 25.96 0.70 1.84 25.98 0.72 1.97 26.00 0.73 2.10 26.02 0.74 2.24 26.04 0.76 2.38 26.06 0.77 2.53 26.08 0.78 2.68 26.10 0.79 2.83 26.12 0.81 2.99 26.14 0.82 3.16 26.16 0.83 3.33 26.18 0.84 3.51 26.20 0.85 3.69 26.22 0.87 3.87 26.24 0.88 4.06 26.26 0.89 4.26 26.28 0.90 4.46 26.30 0.91 4.67 26.32 0.92 4.88 26.34 0.93 5.10 26.36 0.94 5.32 26.38 0.95 5.55 26.40 0.96 5.78 26.42 0.97 6.02 26.44 0.98 6.27 26.46 1.00 6.52 26.48 1.01 6.78 26.50 1.02 7.04 26.52 1.03 7.31 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.54 1.04 7.58 26.56 1.05 7.86 26.58 1.06 8.15 26.60 1.07 8.44 26.62 1.08 8.74 26.64 1.09 9.04 26.66 1.09 9.35 26.68 1.10 9.67 26.70 1.11 9.99 26.72 1.12 10.32 26.74 1.13 10.66 26.76 1.14 11.00 26.78 1.15 11.35 26.80 1.16 11.70 26.82 1.17 12.06 26.84 1.18 12.43 26.86 1.19 12.80 26.88 1.20 13.19 26.90 1.21 13.57 26.92 1.22 13.97 26.94 1.22 14.37 26.96 1.23 14.78 26.98 1.24 15.19 27.00 1.25 15.61 27.02 1.26 16.04 27.04 1.27 16.48 27.06 1.28 16.92 27.08 1.29 17.37 27.10 1.29 17.83 27.12 1.30 18.29 27.14 1.31 18.76 27.16 1.32 19.24 27.18 1.33 19.72 27.20 1.34 20.22 27.22 1.35 20.72 27.24 1.35 21.23 27.26 1.36 21.74 27.28 1.37 22.26 27.30 1.38 22.79 27.32 1.39 23.33 27.34 1.40 23.88 27.36 1.40 24.43 27.38 1.41 24.99 27.40 1.42 25.56 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 11Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch (Existing) [88] Warning: Qout>Qin may require Finer Routing>1 Inflow Area =13.200 ac, Inflow Depth = 2.83" for 2-YR, 24-HR event Inflow =7.58 cfs @ 14.55 hrs, Volume=3.116 af Outflow =7.58 cfs @ 14.55 hrs, Volume=3.116 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 1.69 fps, Min. Travel Time= 0.5 min Avg. Velocity = 0.70 fps, Avg. Travel Time= 1.1 min Peak Storage= 206 cf @ 14.56 hrs, Average Depth at Peak Storage= 0.91' Bank-Full Depth= 2.00', Capacity at Bank-Full= 30.39 cfs 4.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 1.0 '/' Top Width= 8.00' Length= 46.0' Slope= 0.0020 '/' Inlet Invert= 25.10', Outlet Invert= 25.01' Reach DOT-1: NCDOT R/W Ditch (Existing) InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Avg. Depth=0.91' Max Vel=1.69 fps n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs 7.58 cfs7.58 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 12Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch (Existing) Primary Stage-Discharge Discharge (cfs)302826242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 13Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DOT-1: NCDOT R/W Ditch (Existing) Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.10 0.00 0.00 25.12 0.16 0.01 25.14 0.25 0.04 25.16 0.33 0.08 25.18 0.40 0.13 25.20 0.46 0.19 25.22 0.51 0.25 25.24 0.57 0.33 25.26 0.62 0.41 25.28 0.66 0.50 25.30 0.71 0.60 25.32 0.75 0.70 25.34 0.79 0.81 25.36 0.83 0.92 25.38 0.87 1.04 25.40 0.91 1.17 25.42 0.94 1.30 25.44 0.98 1.44 25.46 1.01 1.58 25.48 1.04 1.73 25.50 1.07 1.89 25.52 1.10 2.05 25.54 1.13 2.22 25.56 1.16 2.39 25.58 1.19 2.56 25.60 1.22 2.75 25.62 1.25 2.93 25.64 1.27 3.12 25.66 1.30 3.32 25.68 1.33 3.52 25.70 1.35 3.73 25.72 1.38 3.94 25.74 1.40 4.16 25.76 1.42 4.38 25.78 1.45 4.61 25.80 1.47 4.84 25.82 1.49 5.08 25.84 1.52 5.32 25.86 1.54 5.56 25.88 1.56 5.82 25.90 1.58 6.07 25.92 1.60 6.33 25.94 1.62 6.60 25.96 1.64 6.87 25.98 1.66 7.15 26.00 1.68 7.43 26.02 1.70 7.71 26.04 1.72 8.00 26.06 1.74 8.30 26.08 1.76 8.60 26.10 1.78 8.90 26.12 1.80 9.21 26.14 1.82 9.52 26.16 1.83 9.84 26.18 1.85 10.17 26.20 1.87 10.49 26.22 1.89 10.83 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.24 1.91 11.17 26.26 1.92 11.51 26.28 1.94 11.86 26.30 1.96 12.21 26.32 1.97 12.57 26.34 1.99 12.93 26.36 2.01 13.30 26.38 2.02 13.67 26.40 2.04 14.05 26.42 2.05 14.43 26.44 2.07 14.81 26.46 2.09 15.21 26.48 2.10 15.60 26.50 2.12 16.00 26.52 2.13 16.41 26.54 2.15 16.82 26.56 2.16 17.24 26.58 2.18 17.66 26.60 2.19 18.09 26.62 2.21 18.52 26.64 2.22 18.95 26.66 2.24 19.40 26.68 2.25 19.84 26.70 2.26 20.29 26.72 2.28 20.75 26.74 2.29 21.21 26.76 2.31 21.68 26.78 2.32 22.15 26.80 2.33 22.62 26.82 2.35 23.11 26.84 2.36 23.59 26.86 2.38 24.08 26.88 2.39 24.58 26.90 2.40 25.08 26.92 2.42 25.59 26.94 2.43 26.10 26.96 2.44 26.62 26.98 2.46 27.14 27.00 2.47 27.67 27.02 2.48 28.20 27.04 2.49 28.74 27.06 2.51 29.29 27.08 2.52 29.84 27.10 2.53 30.39 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 14Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch [91] Warning: Storage range exceeded by 5.58' [55] Hint: Peak inflow is 587% of Manning's capacity [63] Warning: Exceeded Reach DC-1 inflow depth by 6.72' @ 16.35 hrs [81] Warning: Exceeded Pond SB-1 by 6.04' @ 16.25 hrs Inflow Area =53.300 ac, Inflow Depth > 2.42" for 2-YR, 24-HR event Inflow =17.43 cfs @ 16.03 hrs, Volume=10.757 af Outflow =17.20 cfs @ 16.63 hrs, Volume=10.747 af, Atten= 1%, Lag= 35.7 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 0.20 fps, Min. Travel Time= 21.9 min Avg. Velocity = 0.09 fps, Avg. Travel Time= 46.9 min Peak Storage= 22,576 cf @ 16.26 hrs, Average Depth at Peak Storage= 7.58' Bank-Full Depth= 2.00', Capacity at Bank-Full= 2.97 cfs 8.00' x 2.00' deep channel, n= 0.800 Sheet flow: Woods+dense brush Side Slope Z-value= 1.0 '/' Top Width= 12.00' Length= 260.0' Slope= 0.0038 '/' Inlet Invert= 25.00', Outlet Invert= 24.00' Reach WDE: West Drainage Easement Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=53.300 ac Avg. Depth=7.58' Max Vel=0.20 fps n=0.800 L=260.0' S=0.0038 '/' Capacity=2.97 cfs 17.43 cfs 17.20 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 15Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch Primary Stage-Discharge Discharge (cfs)210 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 16Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach WDE: West Drainage Easement Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.00 0.00 0.00 25.02 0.01 0.00 25.04 0.01 0.00 25.06 0.02 0.01 25.08 0.02 0.01 25.10 0.02 0.02 25.12 0.03 0.03 25.14 0.03 0.03 25.16 0.03 0.04 25.18 0.04 0.05 25.20 0.04 0.06 25.22 0.04 0.07 25.24 0.04 0.08 25.26 0.05 0.10 25.28 0.05 0.11 25.30 0.05 0.12 25.32 0.05 0.14 25.34 0.05 0.15 25.36 0.06 0.17 25.38 0.06 0.18 25.40 0.06 0.20 25.42 0.06 0.22 25.44 0.06 0.23 25.46 0.06 0.25 25.48 0.07 0.27 25.50 0.07 0.29 25.52 0.07 0.31 25.54 0.07 0.33 25.56 0.07 0.35 25.58 0.07 0.37 25.60 0.08 0.39 25.62 0.08 0.41 25.64 0.08 0.43 25.66 0.08 0.46 25.68 0.08 0.48 25.70 0.08 0.50 25.72 0.08 0.53 25.74 0.09 0.55 25.76 0.09 0.58 25.78 0.09 0.60 25.80 0.09 0.63 25.82 0.09 0.66 25.84 0.09 0.68 25.86 0.09 0.71 25.88 0.09 0.74 25.90 0.10 0.77 25.92 0.10 0.80 25.94 0.10 0.83 25.96 0.10 0.86 25.98 0.10 0.89 26.00 0.10 0.92 26.02 0.10 0.95 26.04 0.10 0.98 26.06 0.11 1.01 26.08 0.11 1.04 26.10 0.11 1.08 26.12 0.11 1.11 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.14 0.11 1.14 26.16 0.11 1.18 26.18 0.11 1.21 26.20 0.11 1.25 26.22 0.11 1.28 26.24 0.11 1.32 26.26 0.12 1.35 26.28 0.12 1.39 26.30 0.12 1.43 26.32 0.12 1.46 26.34 0.12 1.50 26.36 0.12 1.54 26.38 0.12 1.58 26.40 0.12 1.62 26.42 0.12 1.66 26.44 0.12 1.69 26.46 0.13 1.73 26.48 0.13 1.78 26.50 0.13 1.82 26.52 0.13 1.86 26.54 0.13 1.90 26.56 0.13 1.94 26.58 0.13 1.98 26.60 0.13 2.03 26.62 0.13 2.07 26.64 0.13 2.11 26.66 0.13 2.16 26.68 0.14 2.20 26.70 0.14 2.25 26.72 0.14 2.29 26.74 0.14 2.34 26.76 0.14 2.39 26.78 0.14 2.43 26.80 0.14 2.48 26.82 0.14 2.53 26.84 0.14 2.57 26.86 0.14 2.62 26.88 0.14 2.67 26.90 0.14 2.72 26.92 0.15 2.77 26.94 0.15 2.82 26.96 0.15 2.87 26.98 0.15 2.92 27.00 0.15 2.97 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 17Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe [57] Hint: Peaked at 26.74' (Flood elevation advised) [63] Warning: Exceeded Reach DOT-1 inflow depth by 0.73' @ 14.55 hrs Inflow Area =13.200 ac, Inflow Depth = 2.83" for 2-YR, 24-HR event Inflow =7.58 cfs @ 14.55 hrs, Volume=3.116 af Outflow =7.58 cfs @ 14.55 hrs, Volume=3.116 af, Atten= 0%, Lag= 0.0 min Primary =7.58 cfs @ 14.55 hrs, Volume=3.116 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 26.74' @ 14.55 hrs Device Routing Invert Outlet Devices #1 Primary 25.01'24.0" x 84.0' long Culvert RCP, mitered to conform to fill, Ke= 0.700 Outlet Invert= 25.00' S= 0.0001 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean Primary OutFlow Max=7.58 cfs @ 14.55 hrs HW=26.74' (Free Discharge) 1=Culvert (Barrel Controls 7.58 cfs @ 3.51 fps) Pond C-1: Driveway Pipe InflowPrimary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Peak Elev=26.74' 24.0" x 84.0' Culvert 7.58 cfs 7.58 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 18Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe Primary Stage-Discharge Discharge (cfs)9876543210 El e v a t i o n ( f e e t ) 27 26 Culvert DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 19Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond C-1: Driveway Pipe Elevation (feet) Primary (cfs) 25.01 0.00 25.02 0.00 25.03 0.00 25.04 0.00 25.05 0.00 25.06 0.00 25.07 0.00 25.08 0.01 25.09 0.01 25.10 0.01 25.11 0.01 25.12 0.02 25.13 0.02 25.14 0.03 25.15 0.03 25.16 0.04 25.17 0.04 25.18 0.05 25.19 0.06 25.20 0.06 25.21 0.07 25.22 0.08 25.23 0.09 25.24 0.10 25.25 0.11 25.26 0.12 25.27 0.14 25.28 0.15 25.29 0.16 25.30 0.18 25.31 0.19 25.32 0.21 25.33 0.22 25.34 0.24 25.35 0.25 25.36 0.27 25.37 0.29 25.38 0.31 25.39 0.33 25.40 0.35 25.41 0.37 25.42 0.39 25.43 0.41 25.44 0.44 25.45 0.46 25.46 0.48 25.47 0.51 25.48 0.53 25.49 0.56 25.50 0.59 25.51 0.61 25.52 0.64 25.53 0.67 25.54 0.70 25.55 0.73 25.56 0.76 25.57 0.79 Elevation (feet) Primary (cfs) 25.58 0.82 25.59 0.85 25.60 0.88 25.61 0.92 25.62 0.95 25.63 0.99 25.64 1.02 25.65 1.06 25.66 1.09 25.67 1.13 25.68 1.17 25.69 1.20 25.70 1.24 25.71 1.28 25.72 1.32 25.73 1.36 25.74 1.40 25.75 1.44 25.76 1.48 25.77 1.53 25.78 1.57 25.79 1.61 25.80 1.65 25.81 1.70 25.82 1.74 25.83 1.79 25.84 1.83 25.85 1.88 25.86 1.93 25.87 1.98 25.88 2.02 25.89 2.07 25.90 2.12 25.91 2.17 25.92 2.22 25.93 2.27 25.94 2.32 25.95 2.37 25.96 2.42 25.97 2.48 25.98 2.53 25.99 2.58 26.00 2.63 26.01 2.69 26.02 2.74 26.03 2.80 26.04 2.85 26.05 2.91 26.06 2.97 26.07 3.02 26.08 3.08 26.09 3.14 26.10 3.19 26.11 3.25 26.12 3.31 26.13 3.37 26.14 3.43 Elevation (feet) Primary (cfs) 26.15 3.49 26.16 3.55 26.17 3.61 26.18 3.67 26.19 3.73 26.20 3.79 26.21 3.86 26.22 3.92 26.23 3.98 26.24 4.05 26.25 4.11 26.26 4.17 26.27 4.24 26.28 4.30 26.29 4.37 26.30 4.43 26.31 4.50 26.32 4.56 26.33 4.63 26.34 4.70 26.35 4.76 26.36 4.83 26.37 4.90 26.38 4.97 26.39 5.03 26.40 5.10 26.41 5.17 26.42 5.24 26.43 5.31 26.44 5.38 26.45 5.45 26.46 5.52 26.47 5.59 26.48 5.66 26.49 5.73 26.50 5.80 26.51 5.87 26.52 5.94 26.53 6.01 26.54 6.09 26.55 6.16 26.56 6.23 26.57 6.30 26.58 6.38 26.59 6.45 26.60 6.52 26.61 6.59 26.62 6.67 26.63 6.74 26.64 6.81 26.65 6.89 26.66 6.96 26.67 7.04 26.68 7.11 26.69 7.18 26.70 7.26 26.71 7.33 Elevation (feet) Primary (cfs) 26.72 7.41 26.73 7.48 26.74 7.56 26.75 7.63 26.76 7.71 26.77 7.78 26.78 7.86 26.79 7.93 26.80 8.01 26.81 8.08 26.82 8.16 26.83 8.23 26.84 8.31 26.85 8.38 26.86 8.46 26.87 8.54 26.88 8.61 26.89 8.69 26.90 8.76 26.91 8.84 26.92 8.91 26.93 8.99 26.94 9.06 26.95 9.14 26.96 9.21 26.97 9.29 26.98 9.36 26.99 9.44 27.00 9.51 27.01 9.59 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 20Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 Inflow Area =2.800 ac, Inflow Depth > 3.51" for 2-YR, 24-HR event Inflow =8.27 cfs @ 12.21 hrs, Volume=0.819 af Outflow =3.48 cfs @ 12.57 hrs, Volume=0.737 af, Atten= 58%, Lag= 21.1 min Primary =3.48 cfs @ 12.57 hrs, Volume=0.737 af Secondary =0.00 cfs @ 5.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 26.72' @ 12.57 hrs Surf.Area= 24,874 sf Storage= 16,945 cf Plug-Flow detention time= 428.9 min calculated for 0.737 af (90% of inflow) Center-of-Mass det. time= 380.1 min ( 1,182.9 - 802.8 ) Volume Invert Avail.Storage Storage Description #1 26.00'80,094 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 26.00 22,725 0 0 26.50 24,025 11,688 11,688 27.00 26,000 12,506 24,194 28.00 30,000 28,000 52,194 28.90 32,000 27,900 80,094 Device Routing Invert Outlet Devices #1 Primary 25.50'24.0" x 35.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 25.30' S= 0.0057 '/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior #2 Device 1 26.00'3.0" Vert. Skimmer C= 0.600 #3 Device 1 26.50'2.5' long Sharp-Crested Rectangular Weir X 4.00 2 End Contraction(s) 1.0' Crest Height #4 Secondary 27.60'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=3.46 cfs @ 12.57 hrs HW=26.71' (Free Discharge) 1=Culvert (Passes 3.46 cfs of 4.56 cfs potential flow) 2=Skimmer (Orifice Controls 0.18 cfs @ 3.70 fps) 3=Sharp-Crested Rectangular Weir (Weir Controls 3.28 cfs @ 1.55 fps) Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=26.00' (Free Discharge) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 21Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 InflowOutflowPrimarySecondary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 9 8 7 6 5 4 3 2 1 0 Inflow Area=2.800 ac Peak Elev=26.72' Storage=16,945 cf 8.27 cfs 3.48 cfs 3.48 cfs 0.00 cfs Pond SB-1: Basin 1 TotalPrimary Secondary Stage-Discharge Discharge (cfs)9080706050403020100 El e v a t i o n ( f e e t ) 28 27 26 Culvert Skimmer Sharp-Crested Rectangular Weir Broad-Crested Rectangular Weir DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 2-YR, 24-HR Rainfall=4.62"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 22Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond SB-1: Basin 1 Elevation (feet) Discharge (cfs) Primary (cfs) Secondary (cfs) 26.00 0.00 0.00 0.00 26.05 0.01 0.01 0.00 26.10 0.02 0.02 0.00 26.15 0.04 0.04 0.00 26.20 0.06 0.06 0.00 26.25 0.08 0.08 0.00 26.30 0.10 0.10 0.00 26.35 0.11 0.11 0.00 26.40 0.12 0.12 0.00 26.45 0.13 0.13 0.00 26.50 0.14 0.14 0.00 26.55 0.52 0.52 0.00 26.60 1.20 1.20 0.00 26.65 2.08 2.08 0.00 26.70 3.13 3.13 0.00 26.75 4.32 4.32 0.00 26.80 5.14 5.14 0.00 26.85 5.49 5.49 0.00 26.90 5.85 5.85 0.00 26.95 6.21 6.21 0.00 27.00 6.57 6.57 0.00 27.05 6.94 6.94 0.00 27.10 7.31 7.31 0.00 27.15 7.69 7.69 0.00 27.20 8.07 8.07 0.00 27.25 8.44 8.44 0.00 27.30 8.82 8.82 0.00 27.35 9.20 9.20 0.00 27.40 9.58 9.58 0.00 27.45 9.95 9.95 0.00 27.50 10.32 10.32 0.00 27.55 10.69 10.69 0.00 27.60 11.04 11.04 0.00 27.65 11.95 11.40 0.56 27.70 13.31 11.74 1.57 27.75 14.96 12.07 2.89 27.80 16.84 12.38 4.45 27.85 18.96 12.69 6.27 27.90 21.27 12.97 8.30 27.95 23.76 13.23 10.53 28.00 26.41 13.46 12.95 28.05 29.32 13.65 15.67 28.10 32.39 13.79 18.60 28.15 35.56 13.82 21.74 28.20 39.06 13.97 25.10 28.25 42.62 14.35 28.27 28.30 46.29 14.72 31.57 28.35 50.06 15.09 34.98 28.40 53.94 15.44 38.50 28.45 57.91 15.79 42.12 28.50 61.98 16.13 45.85 28.55 66.14 16.46 49.68 28.60 70.39 16.79 53.60 28.65 74.83 17.11 57.72 28.70 79.37 17.42 61.95 28.75 84.01 17.73 66.29 28.80 88.75 18.03 70.72 Elevation (feet) Discharge (cfs) Primary (cfs) Secondary (cfs) 28.85 93.35 18.31 75.05 28.90 97.95 18.50 79.45 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 23Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=6.800 ac Runoff Depth=4.52"Subcatchment DA-1: Proposed Drainage Channel Drainage Ar Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 Runoff=9.25 cfs 2.561 af Runoff Area=13.200 ac Runoff Depth=5.19"Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Ar Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 Runoff=13.91 cfs 5.707 af Runoff Area=43.700 ac Runoff Depth=4.63"Subcatchment Easement: West Drainage Easement Drainage Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 Runoff=30.38 cfs 16.858 af Runoff Area=2.800 ac Runoff Depth>5.97"Subcatchment Lot: Crowatan Lot Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=90 Runoff=13.73 cfs 1.393 af Avg. Depth=1.25' Max Vel=1.09 fps Inflow=9.25 cfs 2.561 afReach DC-1: Drainage Channel n=0.030 L=440.0' S=0.0007 '/' Capacity=25.56 cfs Outflow=9.18 cfs 2.561 af Avg. Depth=1.29' Max Vel=2.03 fps Inflow=13.91 cfs 5.707 afReach DOT-1: NCDOT R/W Ditch (Existing) n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs Outflow=13.90 cfs 5.707 af Avg. Depth=13.94' Max Vel=0.21 fps Inflow=33.74 cfs 20.727 afReach WDE: West Drainage Easement Dit n=0.800 L=260.0' S=0.0038 '/' Capacity=2.97 cfs Outflow=33.42 cfs 20.717 af Peak Elev=27.74' Inflow=13.90 cfs 5.707 afPond C-1: Driveway Pipe 24.0" x 84.0' Culvert Outflow=13.90 cfs 5.707 af Peak Elev=27.01' Storage=24,325 cf Inflow=13.73 cfs 1.393 afPond SB-1: Basin 1 Primary=6.61 cfs 1.308 af Secondary=0.00 cfs 0.000 af Outflow=6.61 cfs 1.308 af Total Runoff Area = 66.500 ac Runoff Volume = 26.520 af Average Runoff Depth = 4.79" 98.80% Pervious Area = 65.700 ac 1.20% Impervious Area = 0.800 ac DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 24Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DA-1: Proposed Drainage Channel Drainage Area Runoff =9.25 cfs @ 13.51 hrs, Volume=2.561 af, Depth= 4.52" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR, 24-HR Rainfall=7.17" Area (ac) CN Description 6.800 77 Woods, Good, HSG D 6.800 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 81.8 1,400 0.0010 0.29 5.71 Trap/Vee/Rect Channel Flow, Bot.W=6.00' D=2.00' Z= 2.0 '/' Top.W=14.00' n= 0.200 115.8 1,500 Total Subcatchment DA-1: Proposed Drainage Channel Drainage Area Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 10-YR 24-HR Rainfall=7.17" Runoff Area=6.800 ac Runoff Volume=2.561 af Runoff Depth=4.52" Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 9.25 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 25Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Area (Off-Site) Runoff =13.91 cfs @ 14.51 hrs, Volume=5.707 af, Depth= 5.19" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR, 24-HR Rainfall=7.17" Area (ac) CN Description 6.600 77 Woods, Good, HSG D 0.600 98 Paved parking & roofs 6.000 89 <50% Grass cover, Poor, HSG D 13.200 83 Weighted Average 12.600 Pervious Area 0.600 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, Dense woods n= 0.200 P2= 4.62" 31.6 150 0.0010 0.08 Shallow Concentrated Flow, Dense woods Forest w/Heavy Litter Kv= 2.5 fps 135.0 2,200 0.0010 0.27 3.26 Trap/Vee/Rect Channel Flow, Bot.W=4.00' D=2.00' Z= 1.0 '/' Top.W=8.00' n= 0.200 200.6 2,450 Total Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Area (Off-Site) Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 10-YR 24-HR Rainfall=7.17" Runoff Area=13.200 ac Runoff Volume=5.707 af Runoff Depth=5.19" Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 13.91 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 26Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Easement: West Drainage Easement Drainage Runoff =30.38 cfs @ 16.05 hrs, Volume=16.858 af, Depth= 4.63" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR, 24-HR Rainfall=7.17" Area (ac) CN Description 35.700 77 Woods, Good, HSG D 0.900 89 Dirt roads, HSG D 6.900 80 >75% Grass cover, Good, HSG D 0.200 98 Paved parking & roofs 43.700 78 Weighted Average 43.500 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 42.2 200 0.0010 0.08 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 231.0 4,200 0.0010 0.30 6.06 Trap/Vee/Rect Channel Flow, Bot.W=8.00' D=2.00' Z= 1.0 '/' Top.W=12.00' n= 0.200 307.2 4,500 Total Subcatchment Easement: West Drainage Easement Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type III 24-hr 10-YR 24-HR Rainfall=7.17" Runoff Area=43.700 ac Runoff Volume=16.858 af Runoff Depth=4.63" Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 30.38 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 27Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Lot: Crowatan Lot Runoff =13.73 cfs @ 12.21 hrs, Volume=1.393 af, Depth> 5.97" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 10-YR, 24-HR Rainfall=7.17" Area (ac) CN Description 2.800 90 Gravel roads, HSG D 2.800 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.0 100 0.0033 0.24 Sheet Flow, Fallow n= 0.050 P2= 4.62" 9.0 500 0.0033 0.92 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 16.0 600 Total Subcatchment Lot: Crowatan Lot Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 10-YR 24-HR Rainfall=7.17" Runoff Area=2.800 ac Runoff Volume=1.393 af Runoff Depth>5.97" Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=90 13.73 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 28Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DC-1: Drainage Channel Inflow Area =6.800 ac, Inflow Depth = 4.52" for 10-YR, 24-HR event Inflow =9.25 cfs @ 13.51 hrs, Volume=2.561 af Outflow =9.18 cfs @ 13.71 hrs, Volume=2.561 af, Atten= 1%, Lag= 11.9 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 1.09 fps, Min. Travel Time= 6.7 min Avg. Velocity = 0.39 fps, Avg. Travel Time= 18.8 min Peak Storage= 3,708 cf @ 13.59 hrs, Average Depth at Peak Storage= 1.25' Bank-Full Depth= 2.00', Capacity at Bank-Full= 25.56 cfs 3.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 3.0 '/' Top Width= 15.00' Length= 440.0' Slope= 0.0007 '/' Inlet Invert= 25.40', Outlet Invert= 25.10' ‡ Reach DC-1: Drainage Channel InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=6.800 ac Avg. Depth=1.25' Max Vel=1.09 fps n=0.030 L=440.0' S=0.0007 '/' Capacity=25.56 cfs 9.25 cfs 9.18 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 29Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DC-1: Drainage Channel Primary Stage-Discharge Discharge (cfs)242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 30Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DC-1: Drainage Channel Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.40 0.00 0.00 25.42 0.09 0.01 25.44 0.15 0.02 25.46 0.19 0.04 25.48 0.23 0.06 25.50 0.26 0.09 25.52 0.29 0.12 25.54 0.32 0.15 25.56 0.35 0.19 25.58 0.37 0.24 25.60 0.40 0.28 25.62 0.42 0.34 25.64 0.44 0.39 25.66 0.46 0.45 25.68 0.48 0.52 25.70 0.50 0.58 25.72 0.52 0.65 25.74 0.53 0.73 25.76 0.55 0.81 25.78 0.57 0.89 25.80 0.58 0.98 25.82 0.60 1.07 25.84 0.62 1.17 25.86 0.63 1.27 25.88 0.65 1.38 25.90 0.66 1.49 25.92 0.68 1.60 25.94 0.69 1.72 25.96 0.70 1.84 25.98 0.72 1.97 26.00 0.73 2.10 26.02 0.74 2.24 26.04 0.76 2.38 26.06 0.77 2.53 26.08 0.78 2.68 26.10 0.79 2.83 26.12 0.81 2.99 26.14 0.82 3.16 26.16 0.83 3.33 26.18 0.84 3.51 26.20 0.85 3.69 26.22 0.87 3.87 26.24 0.88 4.06 26.26 0.89 4.26 26.28 0.90 4.46 26.30 0.91 4.67 26.32 0.92 4.88 26.34 0.93 5.10 26.36 0.94 5.32 26.38 0.95 5.55 26.40 0.96 5.78 26.42 0.97 6.02 26.44 0.98 6.27 26.46 1.00 6.52 26.48 1.01 6.78 26.50 1.02 7.04 26.52 1.03 7.31 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.54 1.04 7.58 26.56 1.05 7.86 26.58 1.06 8.15 26.60 1.07 8.44 26.62 1.08 8.74 26.64 1.09 9.04 26.66 1.09 9.35 26.68 1.10 9.67 26.70 1.11 9.99 26.72 1.12 10.32 26.74 1.13 10.66 26.76 1.14 11.00 26.78 1.15 11.35 26.80 1.16 11.70 26.82 1.17 12.06 26.84 1.18 12.43 26.86 1.19 12.80 26.88 1.20 13.19 26.90 1.21 13.57 26.92 1.22 13.97 26.94 1.22 14.37 26.96 1.23 14.78 26.98 1.24 15.19 27.00 1.25 15.61 27.02 1.26 16.04 27.04 1.27 16.48 27.06 1.28 16.92 27.08 1.29 17.37 27.10 1.29 17.83 27.12 1.30 18.29 27.14 1.31 18.76 27.16 1.32 19.24 27.18 1.33 19.72 27.20 1.34 20.22 27.22 1.35 20.72 27.24 1.35 21.23 27.26 1.36 21.74 27.28 1.37 22.26 27.30 1.38 22.79 27.32 1.39 23.33 27.34 1.40 23.88 27.36 1.40 24.43 27.38 1.41 24.99 27.40 1.42 25.56 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 31Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch (Existing) Inflow Area =13.200 ac, Inflow Depth = 5.19" for 10-YR, 24-HR event Inflow =13.91 cfs @ 14.51 hrs, Volume=5.707 af Outflow =13.90 cfs @ 14.52 hrs, Volume=5.707 af, Atten= 0%, Lag= 0.7 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 2.03 fps, Min. Travel Time= 0.4 min Avg. Velocity = 0.82 fps, Avg. Travel Time= 0.9 min Peak Storage= 315 cf @ 14.52 hrs, Average Depth at Peak Storage= 1.29' Bank-Full Depth= 2.00', Capacity at Bank-Full= 30.39 cfs 4.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 1.0 '/' Top Width= 8.00' Length= 46.0' Slope= 0.0020 '/' Inlet Invert= 25.10', Outlet Invert= 25.01' Reach DOT-1: NCDOT R/W Ditch (Existing) InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Avg. Depth=1.29' Max Vel=2.03 fps n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs 13.91 cfs13.90 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 32Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch (Existing) Primary Stage-Discharge Discharge (cfs)302826242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 33Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DOT-1: NCDOT R/W Ditch (Existing) Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.10 0.00 0.00 25.12 0.16 0.01 25.14 0.25 0.04 25.16 0.33 0.08 25.18 0.40 0.13 25.20 0.46 0.19 25.22 0.51 0.25 25.24 0.57 0.33 25.26 0.62 0.41 25.28 0.66 0.50 25.30 0.71 0.60 25.32 0.75 0.70 25.34 0.79 0.81 25.36 0.83 0.92 25.38 0.87 1.04 25.40 0.91 1.17 25.42 0.94 1.30 25.44 0.98 1.44 25.46 1.01 1.58 25.48 1.04 1.73 25.50 1.07 1.89 25.52 1.10 2.05 25.54 1.13 2.22 25.56 1.16 2.39 25.58 1.19 2.56 25.60 1.22 2.75 25.62 1.25 2.93 25.64 1.27 3.12 25.66 1.30 3.32 25.68 1.33 3.52 25.70 1.35 3.73 25.72 1.38 3.94 25.74 1.40 4.16 25.76 1.42 4.38 25.78 1.45 4.61 25.80 1.47 4.84 25.82 1.49 5.08 25.84 1.52 5.32 25.86 1.54 5.56 25.88 1.56 5.82 25.90 1.58 6.07 25.92 1.60 6.33 25.94 1.62 6.60 25.96 1.64 6.87 25.98 1.66 7.15 26.00 1.68 7.43 26.02 1.70 7.71 26.04 1.72 8.00 26.06 1.74 8.30 26.08 1.76 8.60 26.10 1.78 8.90 26.12 1.80 9.21 26.14 1.82 9.52 26.16 1.83 9.84 26.18 1.85 10.17 26.20 1.87 10.49 26.22 1.89 10.83 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.24 1.91 11.17 26.26 1.92 11.51 26.28 1.94 11.86 26.30 1.96 12.21 26.32 1.97 12.57 26.34 1.99 12.93 26.36 2.01 13.30 26.38 2.02 13.67 26.40 2.04 14.05 26.42 2.05 14.43 26.44 2.07 14.81 26.46 2.09 15.21 26.48 2.10 15.60 26.50 2.12 16.00 26.52 2.13 16.41 26.54 2.15 16.82 26.56 2.16 17.24 26.58 2.18 17.66 26.60 2.19 18.09 26.62 2.21 18.52 26.64 2.22 18.95 26.66 2.24 19.40 26.68 2.25 19.84 26.70 2.26 20.29 26.72 2.28 20.75 26.74 2.29 21.21 26.76 2.31 21.68 26.78 2.32 22.15 26.80 2.33 22.62 26.82 2.35 23.11 26.84 2.36 23.59 26.86 2.38 24.08 26.88 2.39 24.58 26.90 2.40 25.08 26.92 2.42 25.59 26.94 2.43 26.10 26.96 2.44 26.62 26.98 2.46 27.14 27.00 2.47 27.67 27.02 2.48 28.20 27.04 2.49 28.74 27.06 2.51 29.29 27.08 2.52 29.84 27.10 2.53 30.39 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 34Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch [91] Warning: Storage range exceeded by 11.94' [55] Hint: Peak inflow is 1136% of Manning's capacity [63] Warning: Exceeded Reach DC-1 inflow depth by 12.90' @ 16.20 hrs [81] Warning: Exceeded Pond SB-1 by 12.38' @ 16.15 hrs Inflow Area =53.300 ac, Inflow Depth > 4.67" for 10-YR, 24-HR event Inflow =33.74 cfs @ 16.00 hrs, Volume=20.727 af Outflow =33.42 cfs @ 16.51 hrs, Volume=20.717 af, Atten= 1%, Lag= 30.7 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 0.21 fps, Min. Travel Time= 21.1 min Avg. Velocity = 0.10 fps, Avg. Travel Time= 41.5 min Peak Storage= 42,383 cf @ 16.16 hrs, Average Depth at Peak Storage= 13.94' Bank-Full Depth= 2.00', Capacity at Bank-Full= 2.97 cfs 8.00' x 2.00' deep channel, n= 0.800 Sheet flow: Woods+dense brush Side Slope Z-value= 1.0 '/' Top Width= 12.00' Length= 260.0' Slope= 0.0038 '/' Inlet Invert= 25.00', Outlet Invert= 24.00' Reach WDE: West Drainage Easement Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=53.300 ac Avg. Depth=13.94' Max Vel=0.21 fps n=0.800 L=260.0' S=0.0038 '/' Capacity=2.97 cfs 33.74 cfs 33.42 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 35Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch Primary Stage-Discharge Discharge (cfs)210 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 36Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach WDE: West Drainage Easement Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.00 0.00 0.00 25.02 0.01 0.00 25.04 0.01 0.00 25.06 0.02 0.01 25.08 0.02 0.01 25.10 0.02 0.02 25.12 0.03 0.03 25.14 0.03 0.03 25.16 0.03 0.04 25.18 0.04 0.05 25.20 0.04 0.06 25.22 0.04 0.07 25.24 0.04 0.08 25.26 0.05 0.10 25.28 0.05 0.11 25.30 0.05 0.12 25.32 0.05 0.14 25.34 0.05 0.15 25.36 0.06 0.17 25.38 0.06 0.18 25.40 0.06 0.20 25.42 0.06 0.22 25.44 0.06 0.23 25.46 0.06 0.25 25.48 0.07 0.27 25.50 0.07 0.29 25.52 0.07 0.31 25.54 0.07 0.33 25.56 0.07 0.35 25.58 0.07 0.37 25.60 0.08 0.39 25.62 0.08 0.41 25.64 0.08 0.43 25.66 0.08 0.46 25.68 0.08 0.48 25.70 0.08 0.50 25.72 0.08 0.53 25.74 0.09 0.55 25.76 0.09 0.58 25.78 0.09 0.60 25.80 0.09 0.63 25.82 0.09 0.66 25.84 0.09 0.68 25.86 0.09 0.71 25.88 0.09 0.74 25.90 0.10 0.77 25.92 0.10 0.80 25.94 0.10 0.83 25.96 0.10 0.86 25.98 0.10 0.89 26.00 0.10 0.92 26.02 0.10 0.95 26.04 0.10 0.98 26.06 0.11 1.01 26.08 0.11 1.04 26.10 0.11 1.08 26.12 0.11 1.11 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.14 0.11 1.14 26.16 0.11 1.18 26.18 0.11 1.21 26.20 0.11 1.25 26.22 0.11 1.28 26.24 0.11 1.32 26.26 0.12 1.35 26.28 0.12 1.39 26.30 0.12 1.43 26.32 0.12 1.46 26.34 0.12 1.50 26.36 0.12 1.54 26.38 0.12 1.58 26.40 0.12 1.62 26.42 0.12 1.66 26.44 0.12 1.69 26.46 0.13 1.73 26.48 0.13 1.78 26.50 0.13 1.82 26.52 0.13 1.86 26.54 0.13 1.90 26.56 0.13 1.94 26.58 0.13 1.98 26.60 0.13 2.03 26.62 0.13 2.07 26.64 0.13 2.11 26.66 0.13 2.16 26.68 0.14 2.20 26.70 0.14 2.25 26.72 0.14 2.29 26.74 0.14 2.34 26.76 0.14 2.39 26.78 0.14 2.43 26.80 0.14 2.48 26.82 0.14 2.53 26.84 0.14 2.57 26.86 0.14 2.62 26.88 0.14 2.67 26.90 0.14 2.72 26.92 0.15 2.77 26.94 0.15 2.82 26.96 0.15 2.87 26.98 0.15 2.92 27.00 0.15 2.97 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 37Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe [57] Hint: Peaked at 27.74' (Flood elevation advised) [63] Warning: Exceeded Reach DOT-1 inflow depth by 1.35' @ 14.55 hrs Inflow Area =13.200 ac, Inflow Depth = 5.19" for 10-YR, 24-HR event Inflow =13.90 cfs @ 14.52 hrs, Volume=5.707 af Outflow =13.90 cfs @ 14.52 hrs, Volume=5.707 af, Atten= 0%, Lag= 0.0 min Primary =13.90 cfs @ 14.52 hrs, Volume=5.707 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 27.74' @ 14.52 hrs Device Routing Invert Outlet Devices #1 Primary 25.01'24.0" x 84.0' long Culvert RCP, mitered to conform to fill, Ke= 0.700 Outlet Invert= 25.00' S= 0.0001 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean Primary OutFlow Max=13.89 cfs @ 14.52 hrs HW=27.74' (Free Discharge) 1=Culvert (Barrel Controls 13.89 cfs @ 4.42 fps) Pond C-1: Driveway Pipe InflowPrimary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Peak Elev=27.74' 24.0" x 84.0' Culvert 13.90 cfs 13.90 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 38Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe Primary Stage-Discharge Discharge (cfs)131211109876543210 El e v a t i o n ( f e e t ) 27 26 Culvert DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 39Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond C-1: Driveway Pipe Elevation (feet) Primary (cfs) 25.01 0.00 25.03 0.00 25.05 0.00 25.07 0.00 25.09 0.01 25.11 0.01 25.13 0.02 25.15 0.03 25.17 0.04 25.19 0.06 25.21 0.07 25.23 0.09 25.25 0.11 25.27 0.14 25.29 0.16 25.31 0.19 25.33 0.22 25.35 0.25 25.37 0.29 25.39 0.33 25.41 0.37 25.43 0.41 25.45 0.46 25.47 0.51 25.49 0.56 25.51 0.61 25.53 0.67 25.55 0.73 25.57 0.79 25.59 0.85 25.61 0.92 25.63 0.99 25.65 1.06 25.67 1.13 25.69 1.20 25.71 1.28 25.73 1.36 25.75 1.44 25.77 1.53 25.79 1.61 25.81 1.70 25.83 1.79 25.85 1.88 25.87 1.98 25.89 2.07 25.91 2.17 25.93 2.27 25.95 2.37 25.97 2.48 25.99 2.58 26.01 2.69 26.03 2.80 26.05 2.91 26.07 3.02 26.09 3.14 26.11 3.25 26.13 3.37 Elevation (feet) Primary (cfs) 26.15 3.49 26.17 3.61 26.19 3.73 26.21 3.86 26.23 3.98 26.25 4.11 26.27 4.24 26.29 4.37 26.31 4.50 26.33 4.63 26.35 4.76 26.37 4.90 26.39 5.03 26.41 5.17 26.43 5.31 26.45 5.45 26.47 5.59 26.49 5.73 26.51 5.87 26.53 6.01 26.55 6.16 26.57 6.30 26.59 6.45 26.61 6.59 26.63 6.74 26.65 6.89 26.67 7.04 26.69 7.18 26.71 7.33 26.73 7.48 26.75 7.63 26.77 7.78 26.79 7.93 26.81 8.08 26.83 8.23 26.85 8.38 26.87 8.54 26.89 8.69 26.91 8.84 26.93 8.99 26.95 9.14 26.97 9.29 26.99 9.44 27.01 9.59 27.03 9.73 27.05 9.88 27.07 10.03 27.09 10.18 27.11 10.32 27.13 10.47 27.15 10.61 27.17 10.75 27.19 10.89 27.21 11.03 27.23 11.17 27.25 11.31 27.27 11.44 Elevation (feet) Primary (cfs) 27.29 11.58 27.31 11.71 27.33 11.84 27.35 11.96 27.37 12.09 27.39 12.21 27.41 12.33 27.43 12.44 27.45 12.55 27.47 12.66 27.49 12.76 27.51 12.86 27.53 12.95 27.55 13.04 27.57 13.12 27.59 13.19 27.61 13.25 27.63 13.30 27.65 13.33 27.67 13.32 27.69 13.38 27.71 13.57 27.73 13.76 27.75 13.95 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 40Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 [82] Warning: Early inflow requires earlier time span Inflow Area =2.800 ac, Inflow Depth > 5.97" for 10-YR, 24-HR event Inflow =13.73 cfs @ 12.21 hrs, Volume=1.393 af Outflow =6.61 cfs @ 12.52 hrs, Volume=1.308 af, Atten= 52%, Lag= 18.2 min Primary =6.61 cfs @ 12.52 hrs, Volume=1.308 af Secondary =0.00 cfs @ 5.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 27.01' @ 12.52 hrs Surf.Area= 26,020 sf Storage= 24,325 cf Plug-Flow detention time= 276.2 min calculated for 1.308 af (94% of inflow) Center-of-Mass det. time= 242.8 min ( 1,032.9 - 790.1 ) Volume Invert Avail.Storage Storage Description #1 26.00'80,094 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 26.00 22,725 0 0 26.50 24,025 11,688 11,688 27.00 26,000 12,506 24,194 28.00 30,000 28,000 52,194 28.90 32,000 27,900 80,094 Device Routing Invert Outlet Devices #1 Primary 25.50'24.0" x 35.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 25.30' S= 0.0057 '/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior #2 Device 1 26.00'3.0" Vert. Skimmer C= 0.600 #3 Device 1 26.50'2.5' long Sharp-Crested Rectangular Weir X 4.00 2 End Contraction(s) 1.0' Crest Height #4 Secondary 27.60'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=6.60 cfs @ 12.52 hrs HW=27.00' (Free Discharge) 1=Culvert (Barrel Controls 6.60 cfs @ 3.62 fps) 2=Skimmer (Passes < 0.22 cfs potential flow) 3=Sharp-Crested Rectangular Weir (Passes < 11.93 cfs potential flow) Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=26.00' (Free Discharge) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 41Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 InflowOutflowPrimarySecondary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=2.800 ac Peak Elev=27.01' Storage=24,325 cf 13.73 cfs 6.61 cfs6.61 cfs 0.00 cfs Pond SB-1: Basin 1 TotalPrimary Secondary Stage-Discharge Discharge (cfs)9080706050403020100 El e v a t i o n ( f e e t ) 28 27 26 Culvert Skimmer Sharp-Crested Rectangular Weir Broad-Crested Rectangular Weir DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 10-YR, 24-HR Rainfall=7.17"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 42Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond SB-1: Basin 1 Elevation (feet) Discharge (cfs) Primary (cfs) Secondary (cfs) 26.00 0.00 0.00 0.00 26.05 0.01 0.01 0.00 26.10 0.02 0.02 0.00 26.15 0.04 0.04 0.00 26.20 0.06 0.06 0.00 26.25 0.08 0.08 0.00 26.30 0.10 0.10 0.00 26.35 0.11 0.11 0.00 26.40 0.12 0.12 0.00 26.45 0.13 0.13 0.00 26.50 0.14 0.14 0.00 26.55 0.52 0.52 0.00 26.60 1.20 1.20 0.00 26.65 2.08 2.08 0.00 26.70 3.13 3.13 0.00 26.75 4.32 4.32 0.00 26.80 5.14 5.14 0.00 26.85 5.49 5.49 0.00 26.90 5.85 5.85 0.00 26.95 6.21 6.21 0.00 27.00 6.57 6.57 0.00 27.05 6.94 6.94 0.00 27.10 7.31 7.31 0.00 27.15 7.69 7.69 0.00 27.20 8.07 8.07 0.00 27.25 8.44 8.44 0.00 27.30 8.82 8.82 0.00 27.35 9.20 9.20 0.00 27.40 9.58 9.58 0.00 27.45 9.95 9.95 0.00 27.50 10.32 10.32 0.00 27.55 10.69 10.69 0.00 27.60 11.04 11.04 0.00 27.65 11.95 11.40 0.56 27.70 13.31 11.74 1.57 27.75 14.96 12.07 2.89 27.80 16.84 12.38 4.45 27.85 18.96 12.69 6.27 27.90 21.27 12.97 8.30 27.95 23.76 13.23 10.53 28.00 26.41 13.46 12.95 28.05 29.32 13.65 15.67 28.10 32.39 13.79 18.60 28.15 35.56 13.82 21.74 28.20 39.06 13.97 25.10 28.25 42.62 14.35 28.27 28.30 46.29 14.72 31.57 28.35 50.06 15.09 34.98 28.40 53.94 15.44 38.50 28.45 57.91 15.79 42.12 28.50 61.98 16.13 45.85 28.55 66.14 16.46 49.68 28.60 70.39 16.79 53.60 28.65 74.83 17.11 57.72 28.70 79.37 17.42 61.95 28.75 84.01 17.73 66.29 28.80 88.75 18.03 70.72 Elevation (feet) Discharge (cfs) Primary (cfs) Secondary (cfs) 28.85 93.35 18.31 75.05 28.90 97.95 18.50 79.45 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 43Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=6.800 ac Runoff Depth=6.21"Subcatchment DA-1: Proposed Drainage Channel Drainage Ar Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 Runoff=12.68 cfs 3.518 af Runoff Area=13.200 ac Runoff Depth=6.95"Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Ar Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 Runoff=18.53 cfs 7.641 af Runoff Area=43.700 ac Runoff Depth=6.33"Subcatchment Easement: West Drainage Easement Drainage Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 Runoff=41.56 cfs 23.057 af Runoff Area=2.800 ac Runoff Depth>7.75"Subcatchment Lot: Crowatan Lot Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=90 Runoff=17.62 cfs 1.809 af Avg. Depth=1.45' Max Vel=1.18 fps Inflow=12.68 cfs 3.518 afReach DC-1: Drainage Channel n=0.030 L=440.0' S=0.0007 '/' Capacity=25.56 cfs Outflow=12.59 cfs 3.518 af Avg. Depth=1.52' Max Vel=2.21 fps Inflow=18.53 cfs 7.641 afReach DOT-1: NCDOT R/W Ditch (Existing) n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs Outflow=18.52 cfs 7.641 af Avg. Depth=18.71' Max Vel=0.21 fps Inflow=45.97 cfs 28.299 afReach WDE: West Drainage Easement Dit n=0.800 L=260.0' S=0.0038 '/' Capacity=2.97 cfs Outflow=45.59 cfs 28.288 af Peak Elev=28.32' Inflow=18.52 cfs 7.641 afPond C-1: Driveway Pipe 24.0" x 84.0' Culvert Outflow=18.52 cfs 7.641 af Peak Elev=27.21' Storage=29,655 cf Inflow=17.62 cfs 1.809 afPond SB-1: Basin 1 Primary=8.12 cfs 1.723 af Secondary=0.00 cfs 0.000 af Outflow=8.12 cfs 1.723 af Total Runoff Area = 66.500 ac Runoff Volume = 36.025 af Average Runoff Depth = 6.50" 98.80% Pervious Area = 65.700 ac 1.20% Impervious Area = 0.800 ac DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 44Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DA-1: Proposed Drainage Channel Drainage Area Runoff =12.68 cfs @ 13.50 hrs, Volume=3.518 af, Depth= 6.21" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR, 24-HR Rainfall=9.01" Area (ac) CN Description 6.800 77 Woods, Good, HSG D 6.800 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 81.8 1,400 0.0010 0.29 5.71 Trap/Vee/Rect Channel Flow, Bot.W=6.00' D=2.00' Z= 2.0 '/' Top.W=14.00' n= 0.200 115.8 1,500 Total Subcatchment DA-1: Proposed Drainage Channel Drainage Area Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25-YR 24-HR Rainfall=9.01" Runoff Area=6.800 ac Runoff Volume=3.518 af Runoff Depth=6.21" Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 12.68 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 45Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Area (Off-Site) Runoff =18.53 cfs @ 14.51 hrs, Volume=7.641 af, Depth= 6.95" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR, 24-HR Rainfall=9.01" Area (ac) CN Description 6.600 77 Woods, Good, HSG D 0.600 98 Paved parking & roofs 6.000 89 <50% Grass cover, Poor, HSG D 13.200 83 Weighted Average 12.600 Pervious Area 0.600 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, Dense woods n= 0.200 P2= 4.62" 31.6 150 0.0010 0.08 Shallow Concentrated Flow, Dense woods Forest w/Heavy Litter Kv= 2.5 fps 135.0 2,200 0.0010 0.27 3.26 Trap/Vee/Rect Channel Flow, Bot.W=4.00' D=2.00' Z= 1.0 '/' Top.W=8.00' n= 0.200 200.6 2,450 Total Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Area (Off-Site) Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25-YR 24-HR Rainfall=9.01" Runoff Area=13.200 ac Runoff Volume=7.641 af Runoff Depth=6.95" Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 18.53 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 46Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Easement: West Drainage Easement Drainage Runoff =41.56 cfs @ 16.04 hrs, Volume=23.057 af, Depth= 6.33" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR, 24-HR Rainfall=9.01" Area (ac) CN Description 35.700 77 Woods, Good, HSG D 0.900 89 Dirt roads, HSG D 6.900 80 >75% Grass cover, Good, HSG D 0.200 98 Paved parking & roofs 43.700 78 Weighted Average 43.500 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 42.2 200 0.0010 0.08 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 231.0 4,200 0.0010 0.30 6.06 Trap/Vee/Rect Channel Flow, Bot.W=8.00' D=2.00' Z= 1.0 '/' Top.W=12.00' n= 0.200 307.2 4,500 Total Subcatchment Easement: West Drainage Easement Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type III 24-hr 25-YR 24-HR Rainfall=9.01" Runoff Area=43.700 ac Runoff Volume=23.057 af Runoff Depth=6.33" Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 41.56 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 47Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Lot: Crowatan Lot Runoff =17.62 cfs @ 12.21 hrs, Volume=1.809 af, Depth> 7.75" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 25-YR, 24-HR Rainfall=9.01" Area (ac) CN Description 2.800 90 Gravel roads, HSG D 2.800 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.0 100 0.0033 0.24 Sheet Flow, Fallow n= 0.050 P2= 4.62" 9.0 500 0.0033 0.92 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 16.0 600 Total Subcatchment Lot: Crowatan Lot Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 25-YR 24-HR Rainfall=9.01" Runoff Area=2.800 ac Runoff Volume=1.809 af Runoff Depth>7.75" Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=90 17.62 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 48Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DC-1: Drainage Channel Inflow Area =6.800 ac, Inflow Depth = 6.21" for 25-YR, 24-HR event Inflow =12.68 cfs @ 13.50 hrs, Volume=3.518 af Outflow =12.59 cfs @ 13.68 hrs, Volume=3.518 af, Atten= 1%, Lag= 10.4 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 1.18 fps, Min. Travel Time= 6.2 min Avg. Velocity = 0.42 fps, Avg. Travel Time= 17.4 min Peak Storage= 4,684 cf @ 13.57 hrs, Average Depth at Peak Storage= 1.45' Bank-Full Depth= 2.00', Capacity at Bank-Full= 25.56 cfs 3.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 3.0 '/' Top Width= 15.00' Length= 440.0' Slope= 0.0007 '/' Inlet Invert= 25.40', Outlet Invert= 25.10' ‡ Reach DC-1: Drainage Channel InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=6.800 ac Avg. Depth=1.45' Max Vel=1.18 fps n=0.030 L=440.0' S=0.0007 '/' Capacity=25.56 cfs 12.68 cfs 12.59 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 49Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DC-1: Drainage Channel Primary Stage-Discharge Discharge (cfs)242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 50Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DC-1: Drainage Channel Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.40 0.00 0.00 25.42 0.09 0.01 25.44 0.15 0.02 25.46 0.19 0.04 25.48 0.23 0.06 25.50 0.26 0.09 25.52 0.29 0.12 25.54 0.32 0.15 25.56 0.35 0.19 25.58 0.37 0.24 25.60 0.40 0.28 25.62 0.42 0.34 25.64 0.44 0.39 25.66 0.46 0.45 25.68 0.48 0.52 25.70 0.50 0.58 25.72 0.52 0.65 25.74 0.53 0.73 25.76 0.55 0.81 25.78 0.57 0.89 25.80 0.58 0.98 25.82 0.60 1.07 25.84 0.62 1.17 25.86 0.63 1.27 25.88 0.65 1.38 25.90 0.66 1.49 25.92 0.68 1.60 25.94 0.69 1.72 25.96 0.70 1.84 25.98 0.72 1.97 26.00 0.73 2.10 26.02 0.74 2.24 26.04 0.76 2.38 26.06 0.77 2.53 26.08 0.78 2.68 26.10 0.79 2.83 26.12 0.81 2.99 26.14 0.82 3.16 26.16 0.83 3.33 26.18 0.84 3.51 26.20 0.85 3.69 26.22 0.87 3.87 26.24 0.88 4.06 26.26 0.89 4.26 26.28 0.90 4.46 26.30 0.91 4.67 26.32 0.92 4.88 26.34 0.93 5.10 26.36 0.94 5.32 26.38 0.95 5.55 26.40 0.96 5.78 26.42 0.97 6.02 26.44 0.98 6.27 26.46 1.00 6.52 26.48 1.01 6.78 26.50 1.02 7.04 26.52 1.03 7.31 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.54 1.04 7.58 26.56 1.05 7.86 26.58 1.06 8.15 26.60 1.07 8.44 26.62 1.08 8.74 26.64 1.09 9.04 26.66 1.09 9.35 26.68 1.10 9.67 26.70 1.11 9.99 26.72 1.12 10.32 26.74 1.13 10.66 26.76 1.14 11.00 26.78 1.15 11.35 26.80 1.16 11.70 26.82 1.17 12.06 26.84 1.18 12.43 26.86 1.19 12.80 26.88 1.20 13.19 26.90 1.21 13.57 26.92 1.22 13.97 26.94 1.22 14.37 26.96 1.23 14.78 26.98 1.24 15.19 27.00 1.25 15.61 27.02 1.26 16.04 27.04 1.27 16.48 27.06 1.28 16.92 27.08 1.29 17.37 27.10 1.29 17.83 27.12 1.30 18.29 27.14 1.31 18.76 27.16 1.32 19.24 27.18 1.33 19.72 27.20 1.34 20.22 27.22 1.35 20.72 27.24 1.35 21.23 27.26 1.36 21.74 27.28 1.37 22.26 27.30 1.38 22.79 27.32 1.39 23.33 27.34 1.40 23.88 27.36 1.40 24.43 27.38 1.41 24.99 27.40 1.42 25.56 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 51Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch (Existing) Inflow Area =13.200 ac, Inflow Depth = 6.95" for 25-YR, 24-HR event Inflow =18.53 cfs @ 14.51 hrs, Volume=7.641 af Outflow =18.52 cfs @ 14.52 hrs, Volume=7.641 af, Atten= 0%, Lag= 0.6 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 2.21 fps, Min. Travel Time= 0.3 min Avg. Velocity = 0.91 fps, Avg. Travel Time= 0.8 min Peak Storage= 386 cf @ 14.51 hrs, Average Depth at Peak Storage= 1.52' Bank-Full Depth= 2.00', Capacity at Bank-Full= 30.39 cfs 4.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 1.0 '/' Top Width= 8.00' Length= 46.0' Slope= 0.0020 '/' Inlet Invert= 25.10', Outlet Invert= 25.01' Reach DOT-1: NCDOT R/W Ditch (Existing) InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Avg. Depth=1.52' Max Vel=2.21 fps n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs 18.53 cfs18.52 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 52Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch (Existing) Primary Stage-Discharge Discharge (cfs)302826242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 53Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DOT-1: NCDOT R/W Ditch (Existing) Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.10 0.00 0.00 25.12 0.16 0.01 25.14 0.25 0.04 25.16 0.33 0.08 25.18 0.40 0.13 25.20 0.46 0.19 25.22 0.51 0.25 25.24 0.57 0.33 25.26 0.62 0.41 25.28 0.66 0.50 25.30 0.71 0.60 25.32 0.75 0.70 25.34 0.79 0.81 25.36 0.83 0.92 25.38 0.87 1.04 25.40 0.91 1.17 25.42 0.94 1.30 25.44 0.98 1.44 25.46 1.01 1.58 25.48 1.04 1.73 25.50 1.07 1.89 25.52 1.10 2.05 25.54 1.13 2.22 25.56 1.16 2.39 25.58 1.19 2.56 25.60 1.22 2.75 25.62 1.25 2.93 25.64 1.27 3.12 25.66 1.30 3.32 25.68 1.33 3.52 25.70 1.35 3.73 25.72 1.38 3.94 25.74 1.40 4.16 25.76 1.42 4.38 25.78 1.45 4.61 25.80 1.47 4.84 25.82 1.49 5.08 25.84 1.52 5.32 25.86 1.54 5.56 25.88 1.56 5.82 25.90 1.58 6.07 25.92 1.60 6.33 25.94 1.62 6.60 25.96 1.64 6.87 25.98 1.66 7.15 26.00 1.68 7.43 26.02 1.70 7.71 26.04 1.72 8.00 26.06 1.74 8.30 26.08 1.76 8.60 26.10 1.78 8.90 26.12 1.80 9.21 26.14 1.82 9.52 26.16 1.83 9.84 26.18 1.85 10.17 26.20 1.87 10.49 26.22 1.89 10.83 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.24 1.91 11.17 26.26 1.92 11.51 26.28 1.94 11.86 26.30 1.96 12.21 26.32 1.97 12.57 26.34 1.99 12.93 26.36 2.01 13.30 26.38 2.02 13.67 26.40 2.04 14.05 26.42 2.05 14.43 26.44 2.07 14.81 26.46 2.09 15.21 26.48 2.10 15.60 26.50 2.12 16.00 26.52 2.13 16.41 26.54 2.15 16.82 26.56 2.16 17.24 26.58 2.18 17.66 26.60 2.19 18.09 26.62 2.21 18.52 26.64 2.22 18.95 26.66 2.24 19.40 26.68 2.25 19.84 26.70 2.26 20.29 26.72 2.28 20.75 26.74 2.29 21.21 26.76 2.31 21.68 26.78 2.32 22.15 26.80 2.33 22.62 26.82 2.35 23.11 26.84 2.36 23.59 26.86 2.38 24.08 26.88 2.39 24.58 26.90 2.40 25.08 26.92 2.42 25.59 26.94 2.43 26.10 26.96 2.44 26.62 26.98 2.46 27.14 27.00 2.47 27.67 27.02 2.48 28.20 27.04 2.49 28.74 27.06 2.51 29.29 27.08 2.52 29.84 27.10 2.53 30.39 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 54Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch [91] Warning: Storage range exceeded by 16.71' [55] Hint: Peak inflow is 1547% of Manning's capacity [63] Warning: Exceeded Reach DC-1 inflow depth by 17.56' @ 16.15 hrs [81] Warning: Exceeded Pond SB-1 by 17.13' @ 16.15 hrs Inflow Area =53.300 ac, Inflow Depth > 6.37" for 25-YR, 24-HR event Inflow =45.97 cfs @ 15.72 hrs, Volume=28.299 af Outflow =45.59 cfs @ 16.48 hrs, Volume=28.288 af, Atten= 1%, Lag= 45.1 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 0.21 fps, Min. Travel Time= 20.9 min Avg. Velocity = 0.11 fps, Avg. Travel Time= 39.1 min Peak Storage= 57,241 cf @ 16.13 hrs, Average Depth at Peak Storage= 18.71' Bank-Full Depth= 2.00', Capacity at Bank-Full= 2.97 cfs 8.00' x 2.00' deep channel, n= 0.800 Sheet flow: Woods+dense brush Side Slope Z-value= 1.0 '/' Top Width= 12.00' Length= 260.0' Slope= 0.0038 '/' Inlet Invert= 25.00', Outlet Invert= 24.00' Reach WDE: West Drainage Easement Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 50 45 40 35 30 25 20 15 10 5 0 Inflow Area=53.300 ac Avg. Depth=18.71' Max Vel=0.21 fps n=0.800 L=260.0' S=0.0038 '/' Capacity=2.97 cfs 45.97 cfs 45.59 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 55Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch Primary Stage-Discharge Discharge (cfs)210 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 56Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach WDE: West Drainage Easement Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.00 0.00 0.00 25.02 0.01 0.00 25.04 0.01 0.00 25.06 0.02 0.01 25.08 0.02 0.01 25.10 0.02 0.02 25.12 0.03 0.03 25.14 0.03 0.03 25.16 0.03 0.04 25.18 0.04 0.05 25.20 0.04 0.06 25.22 0.04 0.07 25.24 0.04 0.08 25.26 0.05 0.10 25.28 0.05 0.11 25.30 0.05 0.12 25.32 0.05 0.14 25.34 0.05 0.15 25.36 0.06 0.17 25.38 0.06 0.18 25.40 0.06 0.20 25.42 0.06 0.22 25.44 0.06 0.23 25.46 0.06 0.25 25.48 0.07 0.27 25.50 0.07 0.29 25.52 0.07 0.31 25.54 0.07 0.33 25.56 0.07 0.35 25.58 0.07 0.37 25.60 0.08 0.39 25.62 0.08 0.41 25.64 0.08 0.43 25.66 0.08 0.46 25.68 0.08 0.48 25.70 0.08 0.50 25.72 0.08 0.53 25.74 0.09 0.55 25.76 0.09 0.58 25.78 0.09 0.60 25.80 0.09 0.63 25.82 0.09 0.66 25.84 0.09 0.68 25.86 0.09 0.71 25.88 0.09 0.74 25.90 0.10 0.77 25.92 0.10 0.80 25.94 0.10 0.83 25.96 0.10 0.86 25.98 0.10 0.89 26.00 0.10 0.92 26.02 0.10 0.95 26.04 0.10 0.98 26.06 0.11 1.01 26.08 0.11 1.04 26.10 0.11 1.08 26.12 0.11 1.11 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.14 0.11 1.14 26.16 0.11 1.18 26.18 0.11 1.21 26.20 0.11 1.25 26.22 0.11 1.28 26.24 0.11 1.32 26.26 0.12 1.35 26.28 0.12 1.39 26.30 0.12 1.43 26.32 0.12 1.46 26.34 0.12 1.50 26.36 0.12 1.54 26.38 0.12 1.58 26.40 0.12 1.62 26.42 0.12 1.66 26.44 0.12 1.69 26.46 0.13 1.73 26.48 0.13 1.78 26.50 0.13 1.82 26.52 0.13 1.86 26.54 0.13 1.90 26.56 0.13 1.94 26.58 0.13 1.98 26.60 0.13 2.03 26.62 0.13 2.07 26.64 0.13 2.11 26.66 0.13 2.16 26.68 0.14 2.20 26.70 0.14 2.25 26.72 0.14 2.29 26.74 0.14 2.34 26.76 0.14 2.39 26.78 0.14 2.43 26.80 0.14 2.48 26.82 0.14 2.53 26.84 0.14 2.57 26.86 0.14 2.62 26.88 0.14 2.67 26.90 0.14 2.72 26.92 0.15 2.77 26.94 0.15 2.82 26.96 0.15 2.87 26.98 0.15 2.92 27.00 0.15 2.97 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 57Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe [57] Hint: Peaked at 28.32' (Flood elevation advised) [63] Warning: Exceeded Reach DOT-1 inflow depth by 1.70' @ 14.50 hrs Inflow Area =13.200 ac, Inflow Depth = 6.95" for 25-YR, 24-HR event Inflow =18.52 cfs @ 14.52 hrs, Volume=7.641 af Outflow =18.52 cfs @ 14.52 hrs, Volume=7.641 af, Atten= 0%, Lag= 0.0 min Primary =18.52 cfs @ 14.52 hrs, Volume=7.641 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 28.32' @ 14.52 hrs Device Routing Invert Outlet Devices #1 Primary 25.01'24.0" x 84.0' long Culvert RCP, mitered to conform to fill, Ke= 0.700 Outlet Invert= 25.00' S= 0.0001 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean Primary OutFlow Max=18.51 cfs @ 14.52 hrs HW=28.32' (Free Discharge) 1=Culvert (Barrel Controls 18.51 cfs @ 5.89 fps) Pond C-1: Driveway Pipe InflowPrimary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=13.200 ac Peak Elev=28.32' 24.0" x 84.0' Culvert 18.52 cfs 18.52 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 58Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe Primary Stage-Discharge Discharge (cfs)181614121086420 El e v a t i o n ( f e e t ) 28 27 26 Culvert DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 59Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond C-1: Driveway Pipe Elevation (feet) Primary (cfs) 25.01 0.00 25.03 0.00 25.05 0.00 25.07 0.00 25.09 0.01 25.11 0.01 25.13 0.02 25.15 0.03 25.17 0.04 25.19 0.06 25.21 0.07 25.23 0.09 25.25 0.11 25.27 0.14 25.29 0.16 25.31 0.19 25.33 0.22 25.35 0.25 25.37 0.29 25.39 0.33 25.41 0.37 25.43 0.41 25.45 0.46 25.47 0.51 25.49 0.56 25.51 0.61 25.53 0.67 25.55 0.73 25.57 0.79 25.59 0.85 25.61 0.92 25.63 0.99 25.65 1.06 25.67 1.13 25.69 1.20 25.71 1.28 25.73 1.36 25.75 1.44 25.77 1.53 25.79 1.61 25.81 1.70 25.83 1.79 25.85 1.88 25.87 1.98 25.89 2.07 25.91 2.17 25.93 2.27 25.95 2.37 25.97 2.48 25.99 2.58 26.01 2.69 26.03 2.80 26.05 2.91 26.07 3.02 26.09 3.14 26.11 3.25 26.13 3.37 Elevation (feet) Primary (cfs) 26.15 3.49 26.17 3.61 26.19 3.73 26.21 3.86 26.23 3.98 26.25 4.11 26.27 4.24 26.29 4.37 26.31 4.50 26.33 4.63 26.35 4.76 26.37 4.90 26.39 5.03 26.41 5.17 26.43 5.31 26.45 5.45 26.47 5.59 26.49 5.73 26.51 5.87 26.53 6.01 26.55 6.16 26.57 6.30 26.59 6.45 26.61 6.59 26.63 6.74 26.65 6.89 26.67 7.04 26.69 7.18 26.71 7.33 26.73 7.48 26.75 7.63 26.77 7.78 26.79 7.93 26.81 8.08 26.83 8.23 26.85 8.38 26.87 8.54 26.89 8.69 26.91 8.84 26.93 8.99 26.95 9.14 26.97 9.29 26.99 9.44 27.01 9.59 27.03 9.73 27.05 9.88 27.07 10.03 27.09 10.18 27.11 10.32 27.13 10.47 27.15 10.61 27.17 10.75 27.19 10.89 27.21 11.03 27.23 11.17 27.25 11.31 27.27 11.44 Elevation (feet) Primary (cfs) 27.29 11.58 27.31 11.71 27.33 11.84 27.35 11.96 27.37 12.09 27.39 12.21 27.41 12.33 27.43 12.44 27.45 12.55 27.47 12.66 27.49 12.76 27.51 12.86 27.53 12.95 27.55 13.04 27.57 13.12 27.59 13.19 27.61 13.25 27.63 13.30 27.65 13.33 27.67 13.32 27.69 13.38 27.71 13.57 27.73 13.76 27.75 13.95 27.77 14.13 27.79 14.32 27.81 14.50 27.83 14.68 27.85 14.85 27.87 15.02 27.89 15.20 27.91 15.37 27.93 15.53 27.95 15.70 27.97 15.86 27.99 16.03 28.01 16.19 28.03 16.35 28.05 16.51 28.07 16.66 28.09 16.82 28.11 16.97 28.13 17.12 28.15 17.27 28.17 17.42 28.19 17.57 28.21 17.72 28.23 17.86 28.25 18.01 28.27 18.15 28.29 18.30 28.31 18.44 28.33 18.58 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 60Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 [82] Warning: Early inflow requires earlier time span Inflow Area =2.800 ac, Inflow Depth > 7.75" for 25-YR, 24-HR event Inflow =17.62 cfs @ 12.21 hrs, Volume=1.809 af Outflow =8.12 cfs @ 12.53 hrs, Volume=1.723 af, Atten= 54%, Lag= 18.9 min Primary =8.12 cfs @ 12.53 hrs, Volume=1.723 af Secondary =0.00 cfs @ 5.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 27.21' @ 12.53 hrs Surf.Area= 26,827 sf Storage= 29,655 cf Plug-Flow detention time= 225.6 min calculated for 1.721 af (95% of inflow) Center-of-Mass det. time= 199.9 min ( 984.9 - 785.0 ) Volume Invert Avail.Storage Storage Description #1 26.00'80,094 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 26.00 22,725 0 0 26.50 24,025 11,688 11,688 27.00 26,000 12,506 24,194 28.00 30,000 28,000 52,194 28.90 32,000 27,900 80,094 Device Routing Invert Outlet Devices #1 Primary 25.50'24.0" x 35.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 25.30' S= 0.0057 '/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior #2 Device 1 26.00'3.0" Vert. Skimmer C= 0.600 #3 Device 1 26.50'2.5' long Sharp-Crested Rectangular Weir X 4.00 2 End Contraction(s) 1.0' Crest Height #4 Secondary 27.60'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=8.11 cfs @ 12.53 hrs HW=27.21' (Free Discharge) 1=Culvert (Barrel Controls 8.11 cfs @ 3.82 fps) 2=Skimmer (Passes < 0.25 cfs potential flow) 3=Sharp-Crested Rectangular Weir (Passes < 19.87 cfs potential flow) Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=26.00' (Free Discharge) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 61Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 InflowOutflowPrimarySecondary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=2.800 ac Peak Elev=27.21' Storage=29,655 cf 17.62 cfs 8.12 cfs 8.12 cfs 0.00 cfs Pond SB-1: Basin 1 TotalPrimary Secondary Stage-Discharge Discharge (cfs)9080706050403020100 El e v a t i o n ( f e e t ) 28 27 26 Culvert Skimmer Sharp-Crested Rectangular Weir Broad-Crested Rectangular Weir DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 25-YR, 24-HR Rainfall=9.01"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 62Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond SB-1: Basin 1 Elevation (feet) Discharge (cfs) Primary (cfs) Secondary (cfs) 26.00 0.00 0.00 0.00 26.05 0.01 0.01 0.00 26.10 0.02 0.02 0.00 26.15 0.04 0.04 0.00 26.20 0.06 0.06 0.00 26.25 0.08 0.08 0.00 26.30 0.10 0.10 0.00 26.35 0.11 0.11 0.00 26.40 0.12 0.12 0.00 26.45 0.13 0.13 0.00 26.50 0.14 0.14 0.00 26.55 0.52 0.52 0.00 26.60 1.20 1.20 0.00 26.65 2.08 2.08 0.00 26.70 3.13 3.13 0.00 26.75 4.32 4.32 0.00 26.80 5.14 5.14 0.00 26.85 5.49 5.49 0.00 26.90 5.85 5.85 0.00 26.95 6.21 6.21 0.00 27.00 6.57 6.57 0.00 27.05 6.94 6.94 0.00 27.10 7.31 7.31 0.00 27.15 7.69 7.69 0.00 27.20 8.07 8.07 0.00 27.25 8.44 8.44 0.00 27.30 8.82 8.82 0.00 27.35 9.20 9.20 0.00 27.40 9.58 9.58 0.00 27.45 9.95 9.95 0.00 27.50 10.32 10.32 0.00 27.55 10.69 10.69 0.00 27.60 11.04 11.04 0.00 27.65 11.95 11.40 0.56 27.70 13.31 11.74 1.57 27.75 14.96 12.07 2.89 27.80 16.84 12.38 4.45 27.85 18.96 12.69 6.27 27.90 21.27 12.97 8.30 27.95 23.76 13.23 10.53 28.00 26.41 13.46 12.95 28.05 29.32 13.65 15.67 28.10 32.39 13.79 18.60 28.15 35.56 13.82 21.74 28.20 39.06 13.97 25.10 28.25 42.62 14.35 28.27 28.30 46.29 14.72 31.57 28.35 50.06 15.09 34.98 28.40 53.94 15.44 38.50 28.45 57.91 15.79 42.12 28.50 61.98 16.13 45.85 28.55 66.14 16.46 49.68 28.60 70.39 16.79 53.60 28.65 74.83 17.11 57.72 28.70 79.37 17.42 61.95 28.75 84.01 17.73 66.29 28.80 88.75 18.03 70.72 Elevation (feet) Discharge (cfs) Primary (cfs) Secondary (cfs) 28.85 93.35 18.31 75.05 28.90 97.95 18.50 79.45 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 63Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=6.800 ac Runoff Depth=7.80"Subcatchment DA-1: Proposed Drainage Channel Drainage Ar Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 Runoff=15.86 cfs 4.418 af Runoff Area=13.200 ac Runoff Depth>8.58"Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Ar Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 Runoff=22.78 cfs 9.440 af Runoff Area=43.700 ac Runoff Depth=7.93"Subcatchment Easement: West Drainage Easement Drainage Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 Runoff=51.94 cfs 28.876 af Runoff Area=2.800 ac Runoff Depth>9.39"Subcatchment Lot: Crowatan Lot Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=90 Runoff=21.18 cfs 2.191 af Avg. Depth=1.61' Max Vel=1.25 fps Inflow=15.86 cfs 4.418 afReach DC-1: Drainage Channel n=0.030 L=440.0' S=0.0007 '/' Capacity=25.56 cfs Outflow=15.76 cfs 4.418 af Avg. Depth=1.71' Max Vel=2.34 fps Inflow=22.78 cfs 9.440 afReach DOT-1: NCDOT R/W Ditch (Existing) n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs Outflow=22.77 cfs 9.440 af Avg. Depth=23.14' Max Vel=0.21 fps Inflow=57.39 cfs 35.400 afReach WDE: West Drainage Easement Dit n=0.800 L=260.0' S=0.0038 '/' Capacity=2.97 cfs Outflow=56.90 cfs 35.389 af Peak Elev=29.00' Inflow=22.77 cfs 9.440 afPond C-1: Driveway Pipe 24.0" x 84.0' Culvert Outflow=22.77 cfs 9.440 af Peak Elev=27.38' Storage=34,243 cf Inflow=21.18 cfs 2.191 afPond SB-1: Basin 1 Primary=9.39 cfs 2.105 af Secondary=0.00 cfs 0.000 af Outflow=9.39 cfs 2.105 af Total Runoff Area = 66.500 ac Runoff Volume = 44.926 af Average Runoff Depth = 8.11" 98.80% Pervious Area = 65.700 ac 1.20% Impervious Area = 0.800 ac DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 64Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DA-1: Proposed Drainage Channel Drainage Area Runoff =15.86 cfs @ 13.50 hrs, Volume=4.418 af, Depth= 7.80" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 50-YR, 24-HR Rainfall=10.70" Area (ac) CN Description 6.800 77 Woods, Good, HSG D 6.800 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 81.8 1,400 0.0010 0.29 5.71 Trap/Vee/Rect Channel Flow, Bot.W=6.00' D=2.00' Z= 2.0 '/' Top.W=14.00' n= 0.200 115.8 1,500 Total Subcatchment DA-1: Proposed Drainage Channel Drainage Area Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 50-YR 24-HR Rainfall=10.70" Runoff Area=6.800 ac Runoff Volume=4.418 af Runoff Depth=7.80" Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 15.86 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 65Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Area (Off-Site) Runoff =22.78 cfs @ 14.51 hrs, Volume=9.440 af, Depth> 8.58" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 50-YR, 24-HR Rainfall=10.70" Area (ac) CN Description 6.600 77 Woods, Good, HSG D 0.600 98 Paved parking & roofs 6.000 89 <50% Grass cover, Poor, HSG D 13.200 83 Weighted Average 12.600 Pervious Area 0.600 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, Dense woods n= 0.200 P2= 4.62" 31.6 150 0.0010 0.08 Shallow Concentrated Flow, Dense woods Forest w/Heavy Litter Kv= 2.5 fps 135.0 2,200 0.0010 0.27 3.26 Trap/Vee/Rect Channel Flow, Bot.W=4.00' D=2.00' Z= 1.0 '/' Top.W=8.00' n= 0.200 200.6 2,450 Total Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Area (Off-Site) Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 25 24 2322 21 20 19 18 17 16 1514 13 12 11 10 9 87 6 5 4 3 2 1 0 Type III 24-hr 50-YR 24-HR Rainfall=10.70" Runoff Area=13.200 ac Runoff Volume=9.440 af Runoff Depth>8.58" Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 22.78 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 66Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Easement: West Drainage Easement Drainage Runoff =51.94 cfs @ 16.04 hrs, Volume=28.876 af, Depth= 7.93" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 50-YR, 24-HR Rainfall=10.70" Area (ac) CN Description 35.700 77 Woods, Good, HSG D 0.900 89 Dirt roads, HSG D 6.900 80 >75% Grass cover, Good, HSG D 0.200 98 Paved parking & roofs 43.700 78 Weighted Average 43.500 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 42.2 200 0.0010 0.08 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 231.0 4,200 0.0010 0.30 6.06 Trap/Vee/Rect Channel Flow, Bot.W=8.00' D=2.00' Z= 1.0 '/' Top.W=12.00' n= 0.200 307.2 4,500 Total Subcatchment Easement: West Drainage Easement Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 55 50 45 40 35 30 25 20 15 10 5 0 Type III 24-hr 50-YR 24-HR Rainfall=10.70" Runoff Area=43.700 ac Runoff Volume=28.876 af Runoff Depth=7.93" Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 51.94 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 67Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Lot: Crowatan Lot Runoff =21.18 cfs @ 12.21 hrs, Volume=2.191 af, Depth> 9.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 50-YR, 24-HR Rainfall=10.70" Area (ac) CN Description 2.800 90 Gravel roads, HSG D 2.800 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.0 100 0.0033 0.24 Sheet Flow, Fallow n= 0.050 P2= 4.62" 9.0 500 0.0033 0.92 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 16.0 600 Total Subcatchment Lot: Crowatan Lot Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 50-YR 24-HR Rainfall=10.70" Runoff Area=2.800 ac Runoff Volume=2.191 af Runoff Depth>9.39" Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=90 21.18 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 68Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DC-1: Drainage Channel Inflow Area =6.800 ac, Inflow Depth = 7.80" for 50-YR, 24-HR event Inflow =15.86 cfs @ 13.50 hrs, Volume=4.418 af Outflow =15.76 cfs @ 13.66 hrs, Volume=4.418 af, Atten= 1%, Lag= 9.6 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 1.25 fps, Min. Travel Time= 5.8 min Avg. Velocity = 0.44 fps, Avg. Travel Time= 16.5 min Peak Storage= 5,530 cf @ 13.56 hrs, Average Depth at Peak Storage= 1.61' Bank-Full Depth= 2.00', Capacity at Bank-Full= 25.56 cfs 3.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 3.0 '/' Top Width= 15.00' Length= 440.0' Slope= 0.0007 '/' Inlet Invert= 25.40', Outlet Invert= 25.10' ‡ Reach DC-1: Drainage Channel InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=6.800 ac Avg. Depth=1.61' Max Vel=1.25 fps n=0.030 L=440.0' S=0.0007 '/' Capacity=25.56 cfs 15.86 cfs 15.76 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 69Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DC-1: Drainage Channel Primary Stage-Discharge Discharge (cfs)242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 70Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DC-1: Drainage Channel Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.40 0.00 0.00 25.42 0.09 0.01 25.44 0.15 0.02 25.46 0.19 0.04 25.48 0.23 0.06 25.50 0.26 0.09 25.52 0.29 0.12 25.54 0.32 0.15 25.56 0.35 0.19 25.58 0.37 0.24 25.60 0.40 0.28 25.62 0.42 0.34 25.64 0.44 0.39 25.66 0.46 0.45 25.68 0.48 0.52 25.70 0.50 0.58 25.72 0.52 0.65 25.74 0.53 0.73 25.76 0.55 0.81 25.78 0.57 0.89 25.80 0.58 0.98 25.82 0.60 1.07 25.84 0.62 1.17 25.86 0.63 1.27 25.88 0.65 1.38 25.90 0.66 1.49 25.92 0.68 1.60 25.94 0.69 1.72 25.96 0.70 1.84 25.98 0.72 1.97 26.00 0.73 2.10 26.02 0.74 2.24 26.04 0.76 2.38 26.06 0.77 2.53 26.08 0.78 2.68 26.10 0.79 2.83 26.12 0.81 2.99 26.14 0.82 3.16 26.16 0.83 3.33 26.18 0.84 3.51 26.20 0.85 3.69 26.22 0.87 3.87 26.24 0.88 4.06 26.26 0.89 4.26 26.28 0.90 4.46 26.30 0.91 4.67 26.32 0.92 4.88 26.34 0.93 5.10 26.36 0.94 5.32 26.38 0.95 5.55 26.40 0.96 5.78 26.42 0.97 6.02 26.44 0.98 6.27 26.46 1.00 6.52 26.48 1.01 6.78 26.50 1.02 7.04 26.52 1.03 7.31 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.54 1.04 7.58 26.56 1.05 7.86 26.58 1.06 8.15 26.60 1.07 8.44 26.62 1.08 8.74 26.64 1.09 9.04 26.66 1.09 9.35 26.68 1.10 9.67 26.70 1.11 9.99 26.72 1.12 10.32 26.74 1.13 10.66 26.76 1.14 11.00 26.78 1.15 11.35 26.80 1.16 11.70 26.82 1.17 12.06 26.84 1.18 12.43 26.86 1.19 12.80 26.88 1.20 13.19 26.90 1.21 13.57 26.92 1.22 13.97 26.94 1.22 14.37 26.96 1.23 14.78 26.98 1.24 15.19 27.00 1.25 15.61 27.02 1.26 16.04 27.04 1.27 16.48 27.06 1.28 16.92 27.08 1.29 17.37 27.10 1.29 17.83 27.12 1.30 18.29 27.14 1.31 18.76 27.16 1.32 19.24 27.18 1.33 19.72 27.20 1.34 20.22 27.22 1.35 20.72 27.24 1.35 21.23 27.26 1.36 21.74 27.28 1.37 22.26 27.30 1.38 22.79 27.32 1.39 23.33 27.34 1.40 23.88 27.36 1.40 24.43 27.38 1.41 24.99 27.40 1.42 25.56 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 71Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch (Existing) Inflow Area =13.200 ac, Inflow Depth > 8.58" for 50-YR, 24-HR event Inflow =22.78 cfs @ 14.51 hrs, Volume=9.440 af Outflow =22.77 cfs @ 14.51 hrs, Volume=9.440 af, Atten= 0%, Lag= 0.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 2.34 fps, Min. Travel Time= 0.3 min Avg. Velocity = 0.98 fps, Avg. Travel Time= 0.8 min Peak Storage= 448 cf @ 14.51 hrs, Average Depth at Peak Storage= 1.71' Bank-Full Depth= 2.00', Capacity at Bank-Full= 30.39 cfs 4.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 1.0 '/' Top Width= 8.00' Length= 46.0' Slope= 0.0020 '/' Inlet Invert= 25.10', Outlet Invert= 25.01' Reach DOT-1: NCDOT R/W Ditch (Existing) InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=13.200 ac Avg. Depth=1.71' Max Vel=2.34 fps n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs 22.78 cfs22.77 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 72Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch (Existing) Primary Stage-Discharge Discharge (cfs)302826242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 73Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DOT-1: NCDOT R/W Ditch (Existing) Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.10 0.00 0.00 25.12 0.16 0.01 25.14 0.25 0.04 25.16 0.33 0.08 25.18 0.40 0.13 25.20 0.46 0.19 25.22 0.51 0.25 25.24 0.57 0.33 25.26 0.62 0.41 25.28 0.66 0.50 25.30 0.71 0.60 25.32 0.75 0.70 25.34 0.79 0.81 25.36 0.83 0.92 25.38 0.87 1.04 25.40 0.91 1.17 25.42 0.94 1.30 25.44 0.98 1.44 25.46 1.01 1.58 25.48 1.04 1.73 25.50 1.07 1.89 25.52 1.10 2.05 25.54 1.13 2.22 25.56 1.16 2.39 25.58 1.19 2.56 25.60 1.22 2.75 25.62 1.25 2.93 25.64 1.27 3.12 25.66 1.30 3.32 25.68 1.33 3.52 25.70 1.35 3.73 25.72 1.38 3.94 25.74 1.40 4.16 25.76 1.42 4.38 25.78 1.45 4.61 25.80 1.47 4.84 25.82 1.49 5.08 25.84 1.52 5.32 25.86 1.54 5.56 25.88 1.56 5.82 25.90 1.58 6.07 25.92 1.60 6.33 25.94 1.62 6.60 25.96 1.64 6.87 25.98 1.66 7.15 26.00 1.68 7.43 26.02 1.70 7.71 26.04 1.72 8.00 26.06 1.74 8.30 26.08 1.76 8.60 26.10 1.78 8.90 26.12 1.80 9.21 26.14 1.82 9.52 26.16 1.83 9.84 26.18 1.85 10.17 26.20 1.87 10.49 26.22 1.89 10.83 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.24 1.91 11.17 26.26 1.92 11.51 26.28 1.94 11.86 26.30 1.96 12.21 26.32 1.97 12.57 26.34 1.99 12.93 26.36 2.01 13.30 26.38 2.02 13.67 26.40 2.04 14.05 26.42 2.05 14.43 26.44 2.07 14.81 26.46 2.09 15.21 26.48 2.10 15.60 26.50 2.12 16.00 26.52 2.13 16.41 26.54 2.15 16.82 26.56 2.16 17.24 26.58 2.18 17.66 26.60 2.19 18.09 26.62 2.21 18.52 26.64 2.22 18.95 26.66 2.24 19.40 26.68 2.25 19.84 26.70 2.26 20.29 26.72 2.28 20.75 26.74 2.29 21.21 26.76 2.31 21.68 26.78 2.32 22.15 26.80 2.33 22.62 26.82 2.35 23.11 26.84 2.36 23.59 26.86 2.38 24.08 26.88 2.39 24.58 26.90 2.40 25.08 26.92 2.42 25.59 26.94 2.43 26.10 26.96 2.44 26.62 26.98 2.46 27.14 27.00 2.47 27.67 27.02 2.48 28.20 27.04 2.49 28.74 27.06 2.51 29.29 27.08 2.52 29.84 27.10 2.53 30.39 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 74Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch [91] Warning: Storage range exceeded by 21.14' [55] Hint: Peak inflow is 1931% of Manning's capacity [63] Warning: Exceeded Reach DC-1 inflow depth by 21.91' @ 16.15 hrs [81] Warning: Exceeded Pond SB-1 by 21.56' @ 16.10 hrs Inflow Area =53.300 ac, Inflow Depth > 7.97" for 50-YR, 24-HR event Inflow =57.39 cfs @ 15.72 hrs, Volume=35.400 af Outflow =56.90 cfs @ 16.45 hrs, Volume=35.389 af, Atten= 1%, Lag= 44.2 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 0.21 fps, Min. Travel Time= 20.8 min Avg. Velocity = 0.12 fps, Avg. Travel Time= 37.5 min Peak Storage= 71,051 cf @ 16.11 hrs, Average Depth at Peak Storage= 23.14' Bank-Full Depth= 2.00', Capacity at Bank-Full= 2.97 cfs 8.00' x 2.00' deep channel, n= 0.800 Sheet flow: Woods+dense brush Side Slope Z-value= 1.0 '/' Top Width= 12.00' Length= 260.0' Slope= 0.0038 '/' Inlet Invert= 25.00', Outlet Invert= 24.00' Reach WDE: West Drainage Easement Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 60 55 50 45 40 35 30 25 20 15 10 5 0 Inflow Area=53.300 ac Avg. Depth=23.14' Max Vel=0.21 fps n=0.800 L=260.0' S=0.0038 '/' Capacity=2.97 cfs 57.39 cfs 56.90 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 75Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch Primary Stage-Discharge Discharge (cfs)210 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 76Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach WDE: West Drainage Easement Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.00 0.00 0.00 25.02 0.01 0.00 25.04 0.01 0.00 25.06 0.02 0.01 25.08 0.02 0.01 25.10 0.02 0.02 25.12 0.03 0.03 25.14 0.03 0.03 25.16 0.03 0.04 25.18 0.04 0.05 25.20 0.04 0.06 25.22 0.04 0.07 25.24 0.04 0.08 25.26 0.05 0.10 25.28 0.05 0.11 25.30 0.05 0.12 25.32 0.05 0.14 25.34 0.05 0.15 25.36 0.06 0.17 25.38 0.06 0.18 25.40 0.06 0.20 25.42 0.06 0.22 25.44 0.06 0.23 25.46 0.06 0.25 25.48 0.07 0.27 25.50 0.07 0.29 25.52 0.07 0.31 25.54 0.07 0.33 25.56 0.07 0.35 25.58 0.07 0.37 25.60 0.08 0.39 25.62 0.08 0.41 25.64 0.08 0.43 25.66 0.08 0.46 25.68 0.08 0.48 25.70 0.08 0.50 25.72 0.08 0.53 25.74 0.09 0.55 25.76 0.09 0.58 25.78 0.09 0.60 25.80 0.09 0.63 25.82 0.09 0.66 25.84 0.09 0.68 25.86 0.09 0.71 25.88 0.09 0.74 25.90 0.10 0.77 25.92 0.10 0.80 25.94 0.10 0.83 25.96 0.10 0.86 25.98 0.10 0.89 26.00 0.10 0.92 26.02 0.10 0.95 26.04 0.10 0.98 26.06 0.11 1.01 26.08 0.11 1.04 26.10 0.11 1.08 26.12 0.11 1.11 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.14 0.11 1.14 26.16 0.11 1.18 26.18 0.11 1.21 26.20 0.11 1.25 26.22 0.11 1.28 26.24 0.11 1.32 26.26 0.12 1.35 26.28 0.12 1.39 26.30 0.12 1.43 26.32 0.12 1.46 26.34 0.12 1.50 26.36 0.12 1.54 26.38 0.12 1.58 26.40 0.12 1.62 26.42 0.12 1.66 26.44 0.12 1.69 26.46 0.13 1.73 26.48 0.13 1.78 26.50 0.13 1.82 26.52 0.13 1.86 26.54 0.13 1.90 26.56 0.13 1.94 26.58 0.13 1.98 26.60 0.13 2.03 26.62 0.13 2.07 26.64 0.13 2.11 26.66 0.13 2.16 26.68 0.14 2.20 26.70 0.14 2.25 26.72 0.14 2.29 26.74 0.14 2.34 26.76 0.14 2.39 26.78 0.14 2.43 26.80 0.14 2.48 26.82 0.14 2.53 26.84 0.14 2.57 26.86 0.14 2.62 26.88 0.14 2.67 26.90 0.14 2.72 26.92 0.15 2.77 26.94 0.15 2.82 26.96 0.15 2.87 26.98 0.15 2.92 27.00 0.15 2.97 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 77Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe [57] Hint: Peaked at 29.00' (Flood elevation advised) [63] Warning: Exceeded Reach DOT-1 inflow depth by 2.19' @ 14.50 hrs Inflow Area =13.200 ac, Inflow Depth > 8.58" for 50-YR, 24-HR event Inflow =22.77 cfs @ 14.51 hrs, Volume=9.440 af Outflow =22.77 cfs @ 14.51 hrs, Volume=9.440 af, Atten= 0%, Lag= 0.0 min Primary =22.77 cfs @ 14.51 hrs, Volume=9.440 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 29.00' @ 14.51 hrs Device Routing Invert Outlet Devices #1 Primary 25.01'24.0" x 84.0' long Culvert RCP, mitered to conform to fill, Ke= 0.700 Outlet Invert= 25.00' S= 0.0001 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean Primary OutFlow Max=22.76 cfs @ 14.51 hrs HW=29.00' (Free Discharge) 1=Culvert (Barrel Controls 22.76 cfs @ 7.24 fps) Pond C-1: Driveway Pipe InflowPrimary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=13.200 ac Peak Elev=29.00' 24.0" x 84.0' Culvert 22.77 cfs 22.77 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 78Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe Primary Stage-Discharge Discharge (cfs)2220181614121086420 El e v a t i o n ( f e e t ) 29 28 27 26 Culvert DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 79Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond C-1: Driveway Pipe Elevation (feet) Primary (cfs) 25.01 0.00 25.03 0.00 25.05 0.00 25.07 0.00 25.09 0.01 25.11 0.01 25.13 0.02 25.15 0.03 25.17 0.04 25.19 0.06 25.21 0.07 25.23 0.09 25.25 0.11 25.27 0.14 25.29 0.16 25.31 0.19 25.33 0.22 25.35 0.25 25.37 0.29 25.39 0.33 25.41 0.37 25.43 0.41 25.45 0.46 25.47 0.51 25.49 0.56 25.51 0.61 25.53 0.67 25.55 0.73 25.57 0.79 25.59 0.85 25.61 0.92 25.63 0.99 25.65 1.06 25.67 1.13 25.69 1.20 25.71 1.28 25.73 1.36 25.75 1.44 25.77 1.53 25.79 1.61 25.81 1.70 25.83 1.79 25.85 1.88 25.87 1.98 25.89 2.07 25.91 2.17 25.93 2.27 25.95 2.37 25.97 2.48 25.99 2.58 26.01 2.69 26.03 2.80 26.05 2.91 26.07 3.02 26.09 3.14 26.11 3.25 26.13 3.37 Elevation (feet) Primary (cfs) 26.15 3.49 26.17 3.61 26.19 3.73 26.21 3.86 26.23 3.98 26.25 4.11 26.27 4.24 26.29 4.37 26.31 4.50 26.33 4.63 26.35 4.76 26.37 4.90 26.39 5.03 26.41 5.17 26.43 5.31 26.45 5.45 26.47 5.59 26.49 5.73 26.51 5.87 26.53 6.01 26.55 6.16 26.57 6.30 26.59 6.45 26.61 6.59 26.63 6.74 26.65 6.89 26.67 7.04 26.69 7.18 26.71 7.33 26.73 7.48 26.75 7.63 26.77 7.78 26.79 7.93 26.81 8.08 26.83 8.23 26.85 8.38 26.87 8.54 26.89 8.69 26.91 8.84 26.93 8.99 26.95 9.14 26.97 9.29 26.99 9.44 27.01 9.59 27.03 9.73 27.05 9.88 27.07 10.03 27.09 10.18 27.11 10.32 27.13 10.47 27.15 10.61 27.17 10.75 27.19 10.89 27.21 11.03 27.23 11.17 27.25 11.31 27.27 11.44 Elevation (feet) Primary (cfs) 27.29 11.58 27.31 11.71 27.33 11.84 27.35 11.96 27.37 12.09 27.39 12.21 27.41 12.33 27.43 12.44 27.45 12.55 27.47 12.66 27.49 12.76 27.51 12.86 27.53 12.95 27.55 13.04 27.57 13.12 27.59 13.19 27.61 13.25 27.63 13.30 27.65 13.33 27.67 13.32 27.69 13.38 27.71 13.57 27.73 13.76 27.75 13.95 27.77 14.13 27.79 14.32 27.81 14.50 27.83 14.68 27.85 14.85 27.87 15.02 27.89 15.20 27.91 15.37 27.93 15.53 27.95 15.70 27.97 15.86 27.99 16.03 28.01 16.19 28.03 16.35 28.05 16.51 28.07 16.66 28.09 16.82 28.11 16.97 28.13 17.12 28.15 17.27 28.17 17.42 28.19 17.57 28.21 17.72 28.23 17.86 28.25 18.01 28.27 18.15 28.29 18.30 28.31 18.44 28.33 18.58 28.35 18.72 28.37 18.85 28.39 18.99 28.41 19.13 Elevation (feet) Primary (cfs) 28.43 19.26 28.45 19.40 28.47 19.53 28.49 19.66 28.51 19.79 28.53 19.92 28.55 20.05 28.57 20.18 28.59 20.31 28.61 20.44 28.63 20.57 28.65 20.69 28.67 20.82 28.69 20.94 28.71 21.06 28.73 21.19 28.75 21.31 28.77 21.43 28.79 21.55 28.81 21.67 28.83 21.79 28.85 21.91 28.87 22.03 28.89 22.15 28.91 22.26 28.93 22.38 28.95 22.49 28.97 22.61 28.99 22.72 29.01 22.84 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 80Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 [82] Warning: Early inflow requires earlier time span Inflow Area =2.800 ac, Inflow Depth > 9.39" for 50-YR, 24-HR event Inflow =21.18 cfs @ 12.21 hrs, Volume=2.191 af Outflow =9.39 cfs @ 12.54 hrs, Volume=2.105 af, Atten= 56%, Lag= 19.7 min Primary =9.39 cfs @ 12.54 hrs, Volume=2.105 af Secondary =0.00 cfs @ 5.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 27.38' @ 12.54 hrs Surf.Area= 27,503 sf Storage= 34,243 cf Plug-Flow detention time= 198.0 min calculated for 2.105 af (96% of inflow) Center-of-Mass det. time= 174.6 min ( 956.3 - 781.7 ) Volume Invert Avail.Storage Storage Description #1 26.00'80,094 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 26.00 22,725 0 0 26.50 24,025 11,688 11,688 27.00 26,000 12,506 24,194 28.00 30,000 28,000 52,194 28.90 32,000 27,900 80,094 Device Routing Invert Outlet Devices #1 Primary 25.50'24.0" x 35.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 25.30' S= 0.0057 '/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior #2 Device 1 26.00'3.0" Vert. Skimmer C= 0.600 #3 Device 1 26.50'2.5' long Sharp-Crested Rectangular Weir X 4.00 2 End Contraction(s) 1.0' Crest Height #4 Secondary 27.60'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=9.39 cfs @ 12.54 hrs HW=27.37' (Free Discharge) 1=Culvert (Barrel Controls 9.39 cfs @ 3.98 fps) 2=Skimmer (Passes < 0.26 cfs potential flow) 3=Sharp-Crested Rectangular Weir (Passes < 27.55 cfs potential flow) Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=26.00' (Free Discharge) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 81Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 InflowOutflowPrimarySecondary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=2.800 ac Peak Elev=27.38' Storage=34,243 cf 21.18 cfs 9.39 cfs9.39 cfs 0.00 cfs Pond SB-1: Basin 1 TotalPrimary Secondary Stage-Discharge Discharge (cfs)9080706050403020100 El e v a t i o n ( f e e t ) 28 27 26 Culvert Skimmer Sharp-Crested Rectangular Weir Broad-Crested Rectangular Weir DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 50-YR, 24-HR Rainfall=10.70"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 82Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond SB-1: Basin 1 Elevation (feet) Discharge (cfs) Primary (cfs) Secondary (cfs) 26.00 0.00 0.00 0.00 26.05 0.01 0.01 0.00 26.10 0.02 0.02 0.00 26.15 0.04 0.04 0.00 26.20 0.06 0.06 0.00 26.25 0.08 0.08 0.00 26.30 0.10 0.10 0.00 26.35 0.11 0.11 0.00 26.40 0.12 0.12 0.00 26.45 0.13 0.13 0.00 26.50 0.14 0.14 0.00 26.55 0.52 0.52 0.00 26.60 1.20 1.20 0.00 26.65 2.08 2.08 0.00 26.70 3.13 3.13 0.00 26.75 4.32 4.32 0.00 26.80 5.14 5.14 0.00 26.85 5.49 5.49 0.00 26.90 5.85 5.85 0.00 26.95 6.21 6.21 0.00 27.00 6.57 6.57 0.00 27.05 6.94 6.94 0.00 27.10 7.31 7.31 0.00 27.15 7.69 7.69 0.00 27.20 8.07 8.07 0.00 27.25 8.44 8.44 0.00 27.30 8.82 8.82 0.00 27.35 9.20 9.20 0.00 27.40 9.58 9.58 0.00 27.45 9.95 9.95 0.00 27.50 10.32 10.32 0.00 27.55 10.69 10.69 0.00 27.60 11.04 11.04 0.00 27.65 11.95 11.40 0.56 27.70 13.31 11.74 1.57 27.75 14.96 12.07 2.89 27.80 16.84 12.38 4.45 27.85 18.96 12.69 6.27 27.90 21.27 12.97 8.30 27.95 23.76 13.23 10.53 28.00 26.41 13.46 12.95 28.05 29.32 13.65 15.67 28.10 32.39 13.79 18.60 28.15 35.56 13.82 21.74 28.20 39.06 13.97 25.10 28.25 42.62 14.35 28.27 28.30 46.29 14.72 31.57 28.35 50.06 15.09 34.98 28.40 53.94 15.44 38.50 28.45 57.91 15.79 42.12 28.50 61.98 16.13 45.85 28.55 66.14 16.46 49.68 28.60 70.39 16.79 53.60 28.65 74.83 17.11 57.72 28.70 79.37 17.42 61.95 28.75 84.01 17.73 66.29 28.80 88.75 18.03 70.72 Elevation (feet) Discharge (cfs) Primary (cfs) Secondary (cfs) 28.85 93.35 18.31 75.05 28.90 97.95 18.50 79.45 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 83Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=6.800 ac Runoff Depth=9.51"Subcatchment DA-1: Proposed Drainage Channel Drainage Ar Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 Runoff=19.24 cfs 5.392 af Runoff Area=13.200 ac Runoff Depth>10.34"Subcatchment DOT DA: Existing DOT R/W Ditch Drainage A Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 Runoff=27.29 cfs 11.372 af Runoff Area=43.700 ac Runoff Depth=9.65"Subcatchment Easement: West Drainage Easement Drainage Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 Runoff=63.04 cfs 35.158 af Runoff Area=2.800 ac Runoff Depth>11.13"Subcatchment Lot: Crowatan Lot Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=90 Runoff=24.94 cfs 2.598 af Avg. Depth=1.76' Max Vel=1.32 fps Inflow=19.24 cfs 5.392 afReach DC-1: Drainage Channel n=0.030 L=440.0' S=0.0007 '/' Capacity=25.56 cfs Outflow=19.14 cfs 5.392 af Avg. Depth=1.89' Max Vel=2.46 fps Inflow=27.29 cfs 11.372 afReach DOT-1: NCDOT R/W Ditch (Existing) n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs Outflow=27.28 cfs 11.372 af Avg. Depth=27.89' Max Vel=0.21 fps Inflow=69.59 cfs 43.061 afReach WDE: West Drainage Easement Dit n=0.800 L=260.0' S=0.0038 '/' Capacity=2.97 cfs Outflow=69.00 cfs 43.051 af Peak Elev=30.19' Inflow=27.28 cfs 11.372 afPond C-1: Driveway Pipe 24.0" x 84.0' Culvert Outflow=27.28 cfs 11.372 af Peak Elev=27.55' Storage=39,119 cf Inflow=24.94 cfs 2.598 afPond SB-1: Basin 1 Primary=10.69 cfs 2.511 af Secondary=0.00 cfs 0.000 af Outflow=10.69 cfs 2.511 af Total Runoff Area = 66.500 ac Runoff Volume = 54.520 af Average Runoff Depth = 9.84" 98.80% Pervious Area = 65.700 ac 1.20% Impervious Area = 0.800 ac DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 84Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DA-1: Proposed Drainage Channel Drainage Area Runoff =19.24 cfs @ 13.50 hrs, Volume=5.392 af, Depth= 9.51" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR, 24-HR Rainfall=12.50" Area (ac) CN Description 6.800 77 Woods, Good, HSG D 6.800 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 81.8 1,400 0.0010 0.29 5.71 Trap/Vee/Rect Channel Flow, Bot.W=6.00' D=2.00' Z= 2.0 '/' Top.W=14.00' n= 0.200 115.8 1,500 Total Subcatchment DA-1: Proposed Drainage Channel Drainage Area Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Type III 24-hr 100-YR 24-HR Rainfall=12.50" Runoff Area=6.800 ac Runoff Volume=5.392 af Runoff Depth=9.51" Flow Length=1,500' Slope=0.0010 '/' Tc=115.8 min CN=77 19.24 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 85Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Area (Off-Site) Runoff =27.29 cfs @ 14.50 hrs, Volume=11.372 af, Depth>10.34" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR, 24-HR Rainfall=12.50" Area (ac) CN Description 6.600 77 Woods, Good, HSG D 0.600 98 Paved parking & roofs 6.000 89 <50% Grass cover, Poor, HSG D 13.200 83 Weighted Average 12.600 Pervious Area 0.600 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, Dense woods n= 0.200 P2= 4.62" 31.6 150 0.0010 0.08 Shallow Concentrated Flow, Dense woods Forest w/Heavy Litter Kv= 2.5 fps 135.0 2,200 0.0010 0.27 3.26 Trap/Vee/Rect Channel Flow, Bot.W=4.00' D=2.00' Z= 1.0 '/' Top.W=8.00' n= 0.200 200.6 2,450 Total Subcatchment DOT DA: Existing DOT R/W Ditch Drainage Area (Off-Site) Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type III 24-hr 100-YR 24-HR Rainfall=12.50" Runoff Area=13.200 ac Runoff Volume=11.372 af Runoff Depth>10.34" Flow Length=2,450' Slope=0.0010 '/' Tc=200.6 min CN=83 27.29 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 86Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Easement: West Drainage Easement Drainage Runoff =63.04 cfs @ 16.03 hrs, Volume=35.158 af, Depth= 9.65" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR, 24-HR Rainfall=12.50" Area (ac) CN Description 35.700 77 Woods, Good, HSG D 0.900 89 Dirt roads, HSG D 6.900 80 >75% Grass cover, Good, HSG D 0.200 98 Paved parking & roofs 43.700 78 Weighted Average 43.500 Pervious Area 0.200 Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 34.0 100 0.0010 0.05 Sheet Flow, n= 0.200 P2= 4.62" 42.2 200 0.0010 0.08 Shallow Concentrated Flow, Forest w/Heavy Litter Kv= 2.5 fps 231.0 4,200 0.0010 0.30 6.06 Trap/Vee/Rect Channel Flow, Bot.W=8.00' D=2.00' Z= 1.0 '/' Top.W=12.00' n= 0.200 307.2 4,500 Total Subcatchment Easement: West Drainage Easement Drainage Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Type III 24-hr 100-YR 24-HR Rainfall=12.50" Runoff Area=43.700 ac Runoff Volume=35.158 af Runoff Depth=9.65" Flow Length=4,500' Slope=0.0010 '/' Tc=307.2 min CN=78 63.04 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 87Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Lot: Crowatan Lot Runoff =24.94 cfs @ 12.21 hrs, Volume=2.598 af, Depth>11.13" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR, 24-HR Rainfall=12.50" Area (ac) CN Description 2.800 90 Gravel roads, HSG D 2.800 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 7.0 100 0.0033 0.24 Sheet Flow, Fallow n= 0.050 P2= 4.62" 9.0 500 0.0033 0.92 Shallow Concentrated Flow, Unpaved Kv= 16.1 fps 16.0 600 Total Subcatchment Lot: Crowatan Lot Runoff Hydrograph Time (hours) 48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Fl o w ( c f s ) 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Type III 24-hr 100-YR 24-HR Rainfall=12.50" Runoff Area=2.800 ac Runoff Volume=2.598 af Runoff Depth>11.13" Flow Length=600' Slope=0.0033 '/' Tc=16.0 min CN=90 24.94 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 88Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DC-1: Drainage Channel Inflow Area =6.800 ac, Inflow Depth = 9.51" for 100-YR, 24-HR event Inflow =19.24 cfs @ 13.50 hrs, Volume=5.392 af Outflow =19.14 cfs @ 13.65 hrs, Volume=5.392 af, Atten= 1%, Lag= 9.1 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 1.32 fps, Min. Travel Time= 5.6 min Avg. Velocity = 0.47 fps, Avg. Travel Time= 15.6 min Peak Storage= 6,388 cf @ 13.55 hrs, Average Depth at Peak Storage= 1.76' Bank-Full Depth= 2.00', Capacity at Bank-Full= 25.56 cfs 3.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 3.0 '/' Top Width= 15.00' Length= 440.0' Slope= 0.0007 '/' Inlet Invert= 25.40', Outlet Invert= 25.10' ‡ Reach DC-1: Drainage Channel InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Inflow Area=6.800 ac Avg. Depth=1.76' Max Vel=1.32 fps n=0.030 L=440.0' S=0.0007 '/' Capacity=25.56 cfs 19.24 cfs 19.14 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 89Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DC-1: Drainage Channel Primary Stage-Discharge Discharge (cfs)242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 90Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DC-1: Drainage Channel Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.40 0.00 0.00 25.42 0.09 0.01 25.44 0.15 0.02 25.46 0.19 0.04 25.48 0.23 0.06 25.50 0.26 0.09 25.52 0.29 0.12 25.54 0.32 0.15 25.56 0.35 0.19 25.58 0.37 0.24 25.60 0.40 0.28 25.62 0.42 0.34 25.64 0.44 0.39 25.66 0.46 0.45 25.68 0.48 0.52 25.70 0.50 0.58 25.72 0.52 0.65 25.74 0.53 0.73 25.76 0.55 0.81 25.78 0.57 0.89 25.80 0.58 0.98 25.82 0.60 1.07 25.84 0.62 1.17 25.86 0.63 1.27 25.88 0.65 1.38 25.90 0.66 1.49 25.92 0.68 1.60 25.94 0.69 1.72 25.96 0.70 1.84 25.98 0.72 1.97 26.00 0.73 2.10 26.02 0.74 2.24 26.04 0.76 2.38 26.06 0.77 2.53 26.08 0.78 2.68 26.10 0.79 2.83 26.12 0.81 2.99 26.14 0.82 3.16 26.16 0.83 3.33 26.18 0.84 3.51 26.20 0.85 3.69 26.22 0.87 3.87 26.24 0.88 4.06 26.26 0.89 4.26 26.28 0.90 4.46 26.30 0.91 4.67 26.32 0.92 4.88 26.34 0.93 5.10 26.36 0.94 5.32 26.38 0.95 5.55 26.40 0.96 5.78 26.42 0.97 6.02 26.44 0.98 6.27 26.46 1.00 6.52 26.48 1.01 6.78 26.50 1.02 7.04 26.52 1.03 7.31 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.54 1.04 7.58 26.56 1.05 7.86 26.58 1.06 8.15 26.60 1.07 8.44 26.62 1.08 8.74 26.64 1.09 9.04 26.66 1.09 9.35 26.68 1.10 9.67 26.70 1.11 9.99 26.72 1.12 10.32 26.74 1.13 10.66 26.76 1.14 11.00 26.78 1.15 11.35 26.80 1.16 11.70 26.82 1.17 12.06 26.84 1.18 12.43 26.86 1.19 12.80 26.88 1.20 13.19 26.90 1.21 13.57 26.92 1.22 13.97 26.94 1.22 14.37 26.96 1.23 14.78 26.98 1.24 15.19 27.00 1.25 15.61 27.02 1.26 16.04 27.04 1.27 16.48 27.06 1.28 16.92 27.08 1.29 17.37 27.10 1.29 17.83 27.12 1.30 18.29 27.14 1.31 18.76 27.16 1.32 19.24 27.18 1.33 19.72 27.20 1.34 20.22 27.22 1.35 20.72 27.24 1.35 21.23 27.26 1.36 21.74 27.28 1.37 22.26 27.30 1.38 22.79 27.32 1.39 23.33 27.34 1.40 23.88 27.36 1.40 24.43 27.38 1.41 24.99 27.40 1.42 25.56 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 91Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch (Existing) Inflow Area =13.200 ac, Inflow Depth > 10.34" for 100-YR, 24-HR event Inflow =27.29 cfs @ 14.50 hrs, Volume=11.372 af Outflow =27.28 cfs @ 14.51 hrs, Volume=11.372 af, Atten= 0%, Lag= 0.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 2.46 fps, Min. Travel Time= 0.3 min Avg. Velocity = 1.05 fps, Avg. Travel Time= 0.7 min Peak Storage= 511 cf @ 14.51 hrs, Average Depth at Peak Storage= 1.89' Bank-Full Depth= 2.00', Capacity at Bank-Full= 30.39 cfs 4.00' x 2.00' deep channel, n= 0.030 Earth, grassed & winding Side Slope Z-value= 1.0 '/' Top Width= 8.00' Length= 46.0' Slope= 0.0020 '/' Inlet Invert= 25.10', Outlet Invert= 25.01' Reach DOT-1: NCDOT R/W Ditch (Existing) InflowOutflow Hydrograph Time (hours) 484644424038363432302826242220181614121086 Fl o w ( c f s ) 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=13.200 ac Avg. Depth=1.89' Max Vel=2.46 fps n=0.030 L=46.0' S=0.0020 '/' Capacity=30.39 cfs 27.29 cfs27.28 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 92Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach DOT-1: NCDOT R/W Ditch (Existing) Primary Stage-Discharge Discharge (cfs)302826242220181614121086420 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 93Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach DOT-1: NCDOT R/W Ditch (Existing) Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.10 0.00 0.00 25.12 0.16 0.01 25.14 0.25 0.04 25.16 0.33 0.08 25.18 0.40 0.13 25.20 0.46 0.19 25.22 0.51 0.25 25.24 0.57 0.33 25.26 0.62 0.41 25.28 0.66 0.50 25.30 0.71 0.60 25.32 0.75 0.70 25.34 0.79 0.81 25.36 0.83 0.92 25.38 0.87 1.04 25.40 0.91 1.17 25.42 0.94 1.30 25.44 0.98 1.44 25.46 1.01 1.58 25.48 1.04 1.73 25.50 1.07 1.89 25.52 1.10 2.05 25.54 1.13 2.22 25.56 1.16 2.39 25.58 1.19 2.56 25.60 1.22 2.75 25.62 1.25 2.93 25.64 1.27 3.12 25.66 1.30 3.32 25.68 1.33 3.52 25.70 1.35 3.73 25.72 1.38 3.94 25.74 1.40 4.16 25.76 1.42 4.38 25.78 1.45 4.61 25.80 1.47 4.84 25.82 1.49 5.08 25.84 1.52 5.32 25.86 1.54 5.56 25.88 1.56 5.82 25.90 1.58 6.07 25.92 1.60 6.33 25.94 1.62 6.60 25.96 1.64 6.87 25.98 1.66 7.15 26.00 1.68 7.43 26.02 1.70 7.71 26.04 1.72 8.00 26.06 1.74 8.30 26.08 1.76 8.60 26.10 1.78 8.90 26.12 1.80 9.21 26.14 1.82 9.52 26.16 1.83 9.84 26.18 1.85 10.17 26.20 1.87 10.49 26.22 1.89 10.83 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.24 1.91 11.17 26.26 1.92 11.51 26.28 1.94 11.86 26.30 1.96 12.21 26.32 1.97 12.57 26.34 1.99 12.93 26.36 2.01 13.30 26.38 2.02 13.67 26.40 2.04 14.05 26.42 2.05 14.43 26.44 2.07 14.81 26.46 2.09 15.21 26.48 2.10 15.60 26.50 2.12 16.00 26.52 2.13 16.41 26.54 2.15 16.82 26.56 2.16 17.24 26.58 2.18 17.66 26.60 2.19 18.09 26.62 2.21 18.52 26.64 2.22 18.95 26.66 2.24 19.40 26.68 2.25 19.84 26.70 2.26 20.29 26.72 2.28 20.75 26.74 2.29 21.21 26.76 2.31 21.68 26.78 2.32 22.15 26.80 2.33 22.62 26.82 2.35 23.11 26.84 2.36 23.59 26.86 2.38 24.08 26.88 2.39 24.58 26.90 2.40 25.08 26.92 2.42 25.59 26.94 2.43 26.10 26.96 2.44 26.62 26.98 2.46 27.14 27.00 2.47 27.67 27.02 2.48 28.20 27.04 2.49 28.74 27.06 2.51 29.29 27.08 2.52 29.84 27.10 2.53 30.39 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 94Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch [91] Warning: Storage range exceeded by 25.89' [55] Hint: Peak inflow is 2342% of Manning's capacity [63] Warning: Exceeded Reach DC-1 inflow depth by 26.58' @ 16.10 hrs [81] Warning: Exceeded Pond SB-1 by 26.29' @ 16.10 hrs Inflow Area =53.300 ac, Inflow Depth > 9.69" for 100-YR, 24-HR event Inflow =69.59 cfs @ 15.71 hrs, Volume=43.061 af Outflow =69.00 cfs @ 16.44 hrs, Volume=43.051 af, Atten= 1%, Lag= 43.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Max. Velocity= 0.21 fps, Min. Travel Time= 20.7 min Avg. Velocity = 0.12 fps, Avg. Travel Time= 36.1 min Peak Storage= 85,827 cf @ 16.09 hrs, Average Depth at Peak Storage= 27.89' Bank-Full Depth= 2.00', Capacity at Bank-Full= 2.97 cfs 8.00' x 2.00' deep channel, n= 0.800 Sheet flow: Woods+dense brush Side Slope Z-value= 1.0 '/' Top Width= 12.00' Length= 260.0' Slope= 0.0038 '/' Inlet Invert= 25.00', Outlet Invert= 24.00' Reach WDE: West Drainage Easement Ditch InflowOutflow Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Inflow Area=53.300 ac Avg. Depth=27.89' Max Vel=0.21 fps n=0.800 L=260.0' S=0.0038 '/' Capacity=2.97 cfs 69.59 cfs 69.00 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 95Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Reach WDE: West Drainage Easement Ditch Primary Stage-Discharge Discharge (cfs)210 De p t h ( f e e t ) 2 1 0 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 96Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Reach WDE: West Drainage Easement Ditch Elevation (feet) Velocity (ft/sec) Discharge (cfs) 25.00 0.00 0.00 25.02 0.01 0.00 25.04 0.01 0.00 25.06 0.02 0.01 25.08 0.02 0.01 25.10 0.02 0.02 25.12 0.03 0.03 25.14 0.03 0.03 25.16 0.03 0.04 25.18 0.04 0.05 25.20 0.04 0.06 25.22 0.04 0.07 25.24 0.04 0.08 25.26 0.05 0.10 25.28 0.05 0.11 25.30 0.05 0.12 25.32 0.05 0.14 25.34 0.05 0.15 25.36 0.06 0.17 25.38 0.06 0.18 25.40 0.06 0.20 25.42 0.06 0.22 25.44 0.06 0.23 25.46 0.06 0.25 25.48 0.07 0.27 25.50 0.07 0.29 25.52 0.07 0.31 25.54 0.07 0.33 25.56 0.07 0.35 25.58 0.07 0.37 25.60 0.08 0.39 25.62 0.08 0.41 25.64 0.08 0.43 25.66 0.08 0.46 25.68 0.08 0.48 25.70 0.08 0.50 25.72 0.08 0.53 25.74 0.09 0.55 25.76 0.09 0.58 25.78 0.09 0.60 25.80 0.09 0.63 25.82 0.09 0.66 25.84 0.09 0.68 25.86 0.09 0.71 25.88 0.09 0.74 25.90 0.10 0.77 25.92 0.10 0.80 25.94 0.10 0.83 25.96 0.10 0.86 25.98 0.10 0.89 26.00 0.10 0.92 26.02 0.10 0.95 26.04 0.10 0.98 26.06 0.11 1.01 26.08 0.11 1.04 26.10 0.11 1.08 26.12 0.11 1.11 Elevation (feet) Velocity (ft/sec) Discharge (cfs) 26.14 0.11 1.14 26.16 0.11 1.18 26.18 0.11 1.21 26.20 0.11 1.25 26.22 0.11 1.28 26.24 0.11 1.32 26.26 0.12 1.35 26.28 0.12 1.39 26.30 0.12 1.43 26.32 0.12 1.46 26.34 0.12 1.50 26.36 0.12 1.54 26.38 0.12 1.58 26.40 0.12 1.62 26.42 0.12 1.66 26.44 0.12 1.69 26.46 0.13 1.73 26.48 0.13 1.78 26.50 0.13 1.82 26.52 0.13 1.86 26.54 0.13 1.90 26.56 0.13 1.94 26.58 0.13 1.98 26.60 0.13 2.03 26.62 0.13 2.07 26.64 0.13 2.11 26.66 0.13 2.16 26.68 0.14 2.20 26.70 0.14 2.25 26.72 0.14 2.29 26.74 0.14 2.34 26.76 0.14 2.39 26.78 0.14 2.43 26.80 0.14 2.48 26.82 0.14 2.53 26.84 0.14 2.57 26.86 0.14 2.62 26.88 0.14 2.67 26.90 0.14 2.72 26.92 0.15 2.77 26.94 0.15 2.82 26.96 0.15 2.87 26.98 0.15 2.92 27.00 0.15 2.97 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 97Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe [57] Hint: Peaked at 30.19' (Flood elevation advised) [63] Warning: Exceeded Reach DOT-1 inflow depth by 3.20' @ 14.50 hrs Inflow Area =13.200 ac, Inflow Depth > 10.34" for 100-YR, 24-HR event Inflow =27.28 cfs @ 14.51 hrs, Volume=11.372 af Outflow =27.28 cfs @ 14.51 hrs, Volume=11.372 af, Atten= 0%, Lag= 0.0 min Primary =27.28 cfs @ 14.51 hrs, Volume=11.372 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 30.19' @ 14.51 hrs Device Routing Invert Outlet Devices #1 Primary 25.01'24.0" x 84.0' long Culvert RCP, mitered to conform to fill, Ke= 0.700 Outlet Invert= 25.00' S= 0.0001 '/' Cc= 0.900 n= 0.011 Concrete pipe, straight & clean Primary OutFlow Max=27.27 cfs @ 14.51 hrs HW=30.19' (Free Discharge) 1=Culvert (Inlet Controls 27.27 cfs @ 8.68 fps) Pond C-1: Driveway Pipe InflowPrimary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=13.200 ac Peak Elev=30.19' 24.0" x 84.0' Culvert 27.28 cfs 27.28 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 98Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond C-1: Driveway Pipe Primary Stage-Discharge Discharge (cfs)26242220181614121086420 El e v a t i o n ( f e e t ) 30 29 28 27 26 Culvert DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 99Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond C-1: Driveway Pipe Elevation (feet) Primary (cfs) 25.01 0.00 25.05 0.00 25.09 0.01 25.13 0.02 25.17 0.04 25.21 0.07 25.25 0.11 25.29 0.16 25.33 0.22 25.37 0.29 25.41 0.37 25.45 0.46 25.49 0.56 25.53 0.67 25.57 0.79 25.61 0.92 25.65 1.06 25.69 1.20 25.73 1.36 25.77 1.53 25.81 1.70 25.85 1.88 25.89 2.07 25.93 2.27 25.97 2.48 26.01 2.69 26.05 2.91 26.09 3.14 26.13 3.37 26.17 3.61 26.21 3.86 26.25 4.11 26.29 4.37 26.33 4.63 26.37 4.90 26.41 5.17 26.45 5.45 26.49 5.73 26.53 6.01 26.57 6.30 26.61 6.59 26.65 6.89 26.69 7.18 26.73 7.48 26.77 7.78 26.81 8.08 26.85 8.38 26.89 8.69 26.93 8.99 26.97 9.29 27.01 9.59 27.05 9.88 27.09 10.18 27.13 10.47 27.17 10.75 27.21 11.03 27.25 11.31 Elevation (feet) Primary (cfs) 27.29 11.58 27.33 11.84 27.37 12.09 27.41 12.33 27.45 12.55 27.49 12.76 27.53 12.95 27.57 13.12 27.61 13.25 27.65 13.33 27.69 13.38 27.73 13.76 27.77 14.13 27.81 14.50 27.85 14.85 27.89 15.20 27.93 15.53 27.97 15.86 28.01 16.19 28.05 16.51 28.09 16.82 28.13 17.12 28.17 17.42 28.21 17.72 28.25 18.01 28.29 18.30 28.33 18.58 28.37 18.85 28.41 19.13 28.45 19.40 28.49 19.66 28.53 19.92 28.57 20.18 28.61 20.44 28.65 20.69 28.69 20.94 28.73 21.19 28.77 21.43 28.81 21.67 28.85 21.91 28.89 22.15 28.93 22.38 28.97 22.61 29.01 22.84 29.05 23.06 29.09 23.29 29.13 23.51 29.17 23.73 29.21 23.88 29.25 24.02 29.29 24.17 29.33 24.32 29.37 24.47 29.41 24.61 29.45 24.76 29.49 24.90 29.53 25.04 Elevation (feet) Primary (cfs) 29.57 25.18 29.61 25.32 29.65 25.46 29.69 25.60 29.73 25.74 29.77 25.88 29.81 26.02 29.85 26.15 29.89 26.29 29.93 26.43 29.97 26.56 30.01 26.69 30.05 26.83 30.09 26.96 30.13 27.09 30.17 27.22 30.21 27.35 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 100Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 [82] Warning: Early inflow requires earlier time span Inflow Area =2.800 ac, Inflow Depth > 11.13" for 100-YR, 24-HR event Inflow =24.94 cfs @ 12.21 hrs, Volume=2.598 af Outflow =10.69 cfs @ 12.55 hrs, Volume=2.511 af, Atten= 57%, Lag= 20.3 min Primary =10.69 cfs @ 12.55 hrs, Volume=2.511 af Secondary =0.00 cfs @ 5.00 hrs, Volume=0.000 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 27.55' @ 12.55 hrs Surf.Area= 28,203 sf Storage= 39,119 cf Plug-Flow detention time= 175.9 min calculated for 2.511 af (97% of inflow) Center-of-Mass det. time= 155.6 min ( 934.7 - 779.2 ) Volume Invert Avail.Storage Storage Description #1 26.00'80,094 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 26.00 22,725 0 0 26.50 24,025 11,688 11,688 27.00 26,000 12,506 24,194 28.00 30,000 28,000 52,194 28.90 32,000 27,900 80,094 Device Routing Invert Outlet Devices #1 Primary 25.50'24.0" x 35.0' long Culvert CPP, projecting, no headwall, Ke= 0.900 Outlet Invert= 25.30' S= 0.0057 '/' Cc= 0.900 n= 0.020 Corrugated PE, corrugated interior #2 Device 1 26.00'3.0" Vert. Skimmer C= 0.600 #3 Device 1 26.50'2.5' long Sharp-Crested Rectangular Weir X 4.00 2 End Contraction(s) 1.0' Crest Height #4 Secondary 27.60'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=10.69 cfs @ 12.55 hrs HW=27.55' (Free Discharge) 1=Culvert (Barrel Controls 10.69 cfs @ 4.12 fps) 2=Skimmer (Passes < 0.28 cfs potential flow) 3=Sharp-Crested Rectangular Weir (Passes < 36.40 cfs potential flow) Secondary OutFlow Max=0.00 cfs @ 5.00 hrs HW=26.00' (Free Discharge) 4=Broad-Crested Rectangular Weir ( Controls 0.00 cfs) DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 101Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 InflowOutflowPrimarySecondary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 26 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=2.800 ac Peak Elev=27.55' Storage=39,119 cf 24.94 cfs 10.69 cfs 10.69 cfs 0.00 cfs Pond SB-1: Basin 1 TotalPrimary Secondary Stage-Discharge Discharge (cfs)9080706050403020100 El e v a t i o n ( f e e t ) 28 27 26 Culvert Skimmer Sharp-Crested Rectangular Weir Broad-Crested Rectangular Weir DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Post-Construction Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._JCL_Apr_RTC Page 102Prepared by Smith Gardner, Inc. 4/29/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond SB-1: Basin 1 Elevation (feet) Discharge (cfs) Primary (cfs) Secondary (cfs) 26.00 0.00 0.00 0.00 26.05 0.01 0.01 0.00 26.10 0.02 0.02 0.00 26.15 0.04 0.04 0.00 26.20 0.06 0.06 0.00 26.25 0.08 0.08 0.00 26.30 0.10 0.10 0.00 26.35 0.11 0.11 0.00 26.40 0.12 0.12 0.00 26.45 0.13 0.13 0.00 26.50 0.14 0.14 0.00 26.55 0.52 0.52 0.00 26.60 1.20 1.20 0.00 26.65 2.08 2.08 0.00 26.70 3.13 3.13 0.00 26.75 4.32 4.32 0.00 26.80 5.14 5.14 0.00 26.85 5.49 5.49 0.00 26.90 5.85 5.85 0.00 26.95 6.21 6.21 0.00 27.00 6.57 6.57 0.00 27.05 6.94 6.94 0.00 27.10 7.31 7.31 0.00 27.15 7.69 7.69 0.00 27.20 8.07 8.07 0.00 27.25 8.44 8.44 0.00 27.30 8.82 8.82 0.00 27.35 9.20 9.20 0.00 27.40 9.58 9.58 0.00 27.45 9.95 9.95 0.00 27.50 10.32 10.32 0.00 27.55 10.69 10.69 0.00 27.60 11.04 11.04 0.00 27.65 11.95 11.40 0.56 27.70 13.31 11.74 1.57 27.75 14.96 12.07 2.89 27.80 16.84 12.38 4.45 27.85 18.96 12.69 6.27 27.90 21.27 12.97 8.30 27.95 23.76 13.23 10.53 28.00 26.41 13.46 12.95 28.05 29.32 13.65 15.67 28.10 32.39 13.79 18.60 28.15 35.56 13.82 21.74 28.20 39.06 13.97 25.10 28.25 42.62 14.35 28.27 28.30 46.29 14.72 31.57 28.35 50.06 15.09 34.98 28.40 53.94 15.44 38.50 28.45 57.91 15.79 42.12 28.50 61.98 16.13 45.85 28.55 66.14 16.46 49.68 28.60 70.39 16.79 53.60 28.65 74.83 17.11 57.72 28.70 79.37 17.42 61.95 28.75 84.01 17.73 66.29 28.80 88.75 18.03 70.72 Elevation (feet) Discharge (cfs) Primary (cfs) Secondary (cfs) 28.85 93.35 18.31 75.05 28.90 97.95 18.50 79.45 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Lot Crowatan Lot SB-1 Basin 1 (clogged) Drainage Diagram for SRR Crowatan Rd Post Con._Clogged Pond Prepared by Smith Gardner, Inc. 3/20/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcat Reach Pond Link Emergency Spillway Evaluation Clogged Pond Scenario DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Clogged Pond Scenario SRR Crowatan Rd Post Con._Clogged Pond Page 2Prepared by Smith Gardner, Inc. 3/20/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres)CN Description (subcats) 2.800 90 Gravel roads, HSG D (Lot) 2.800 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Clogged Pond Scenario Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._Clogged Pond Page 3Prepared by Smith Gardner, Inc. 3/20/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Time span=5.00-48.00 hrs, dt=0.05 hrs, 861 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=2.800 ac Runoff Depth>11.14"Subcatchment Lot: Crowatan Lot Tc=20.0 min CN=90 Runoff=22.86 cfs 2.599 af Peak Elev=27.95' Storage=61,808 cf Inflow=22.86 cfs 2.599 afPond SB-1: Basin 1 (clogged) Outflow=10.67 cfs 1.416 af Total Runoff Area = 2.800 ac Runoff Volume = 2.599 af Average Runoff Depth = 11.14" 100.00% Pervious Area = 2.800 ac 0.00% Impervious Area = 0.000 ac DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Clogged Pond Scenario Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._Clogged Pond Page 4Prepared by Smith Gardner, Inc. 3/20/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Subcatchment Lot: Crowatan Lot Runoff =22.86 cfs @ 12.26 hrs, Volume=2.599 af, Depth>11.14" Runoff by SCS TR-20 method, UH=SCS, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Type III 24-hr 100-YR, 24-HR Rainfall=12.50" Area (ac) CN Description 2.800 90 Gravel roads, HSG D 2.800 Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet)(ft/ft) (ft/sec)(cfs) 20.0 Direct Entry, Subcatchment Lot: Crowatan Lot Runoff Hydrograph Time (hours)48474645444342414039383736353433323130292827262524232221201918171615141312111098765 Flo w ( c f s ) 25 24 23 22 21 2019 18 17 16 15 14 1312 11 10 9 8 76 5 4 3 2 1 0 Type III 24-hr 100-YR 24-HR Rainfall=12.50" Runoff Area=2.800 ac Runoff Volume=2.599 af Runoff Depth>11.14" Tc=20.0 min CN=90 22.86 cfs DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Clogged Pond Scenario Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._Clogged Pond Page 5Prepared by Smith Gardner, Inc. 3/20/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 (clogged) [82] Warning: Early inflow requires earlier time span Inflow Area =2.800 ac, Inflow Depth > 11.14" for 100-YR, 24-HR event Inflow =22.86 cfs @ 12.26 hrs, Volume=2.599 af Outflow =10.67 cfs @ 12.61 hrs, Volume=1.416 af, Atten= 53%, Lag= 21.1 min Primary =10.67 cfs @ 12.61 hrs, Volume=1.416 af Routing by Stor-Ind method, Time Span= 5.00-48.00 hrs, dt= 0.05 hrs Peak Elev= 27.95' @ 12.61 hrs Surf.Area= 29,811 sf Storage= 61,808 cf Plug-Flow detention time= 245.4 min calculated for 1.416 af (54% of inflow) Center-of-Mass det. time= 133.2 min ( 915.9 - 782.7 ) Volume Invert Avail.Storage Storage Description #1 25.50'91,117 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet)(sq-ft)(cubic-feet)(cubic-feet) 25.50 21,370 0 0 26.00 22,725 11,024 11,024 26.50 24,025 11,688 22,711 27.00 26,000 12,506 35,218 28.00 30,000 28,000 63,218 28.90 32,000 27,900 91,117 Device Routing Invert Outlet Devices #1 Primary 27.60'20.0' long x 10.0' breadth Broad-Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64 Primary OutFlow Max=10.61 cfs @ 12.61 hrs HW=27.95' (Free Discharge) 1=Broad-Crested Rectangular Weir (Weir Controls 10.61 cfs @ 1.51 fps) DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Clogged Pond Scenario Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._Clogged Pond Page 6Prepared by Smith Gardner, Inc. 3/20/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Pond SB-1: Basin 1 (clogged) InflowPrimary Hydrograph Time (hours)484644424038363432302826242220181614121086 Fl o w ( c f s ) 24 22 20 18 16 14 12 10 8 6 4 2 0 Inflow Area=2.800 ac Peak Elev=27.95' Storage=61,808 cf 22.86 cfs 10.67 cfs Pond SB-1: Basin 1 (clogged) Primary Stage-Discharge Discharge (cfs)757065605550454035302520151050 El e v a t i o n ( f e e t ) 28 27 26 Broad-Crested Rectangular Weir DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Clogged Pond Scenario Type III 24-hr 100-YR, 24-HR Rainfall=12.50"SRR Crowatan Rd Post Con._Clogged Pond Page 7Prepared by Smith Gardner, Inc. 3/20/2024HydroCAD® 8.00 s/n 004004 © 2006 HydroCAD Software Solutions LLC Stage-Discharge for Pond SB-1: Basin 1 (clogged) Elevation (feet) Primary (cfs) 25.50 0.00 25.52 0.00 25.54 0.00 25.56 0.00 25.58 0.00 25.60 0.00 25.62 0.00 25.64 0.00 25.66 0.00 25.68 0.00 25.70 0.00 25.72 0.00 25.74 0.00 25.76 0.00 25.78 0.00 25.80 0.00 25.82 0.00 25.84 0.00 25.86 0.00 25.88 0.00 25.90 0.00 25.92 0.00 25.94 0.00 25.96 0.00 25.98 0.00 26.00 0.00 26.02 0.00 26.04 0.00 26.06 0.00 26.08 0.00 26.10 0.00 26.12 0.00 26.14 0.00 26.16 0.00 26.18 0.00 26.20 0.00 26.22 0.00 26.24 0.00 26.26 0.00 26.28 0.00 26.30 0.00 26.32 0.00 26.34 0.00 26.36 0.00 26.38 0.00 26.40 0.00 26.42 0.00 26.44 0.00 26.46 0.00 26.48 0.00 26.50 0.00 26.52 0.00 26.54 0.00 26.56 0.00 26.58 0.00 26.60 0.00 26.62 0.00 Elevation (feet) Primary (cfs) 26.64 0.00 26.66 0.00 26.68 0.00 26.70 0.00 26.72 0.00 26.74 0.00 26.76 0.00 26.78 0.00 26.80 0.00 26.82 0.00 26.84 0.00 26.86 0.00 26.88 0.00 26.90 0.00 26.92 0.00 26.94 0.00 26.96 0.00 26.98 0.00 27.00 0.00 27.02 0.00 27.04 0.00 27.06 0.00 27.08 0.00 27.10 0.00 27.12 0.00 27.14 0.00 27.16 0.00 27.18 0.00 27.20 0.00 27.22 0.00 27.24 0.00 27.26 0.00 27.28 0.00 27.30 0.00 27.32 0.00 27.34 0.00 27.36 0.00 27.38 0.00 27.40 0.00 27.42 0.00 27.44 0.00 27.46 0.00 27.48 0.00 27.50 0.00 27.52 0.00 27.54 0.00 27.56 0.00 27.58 0.00 27.60 0.00 27.62 0.14 27.64 0.40 27.66 0.73 27.68 1.13 27.70 1.57 27.72 2.07 27.74 2.61 27.76 3.19 Elevation (feet) Primary (cfs) 27.78 3.80 27.80 4.45 27.82 5.15 27.84 5.89 27.86 6.66 27.88 7.46 27.90 8.30 27.92 9.17 27.94 10.07 27.96 11.00 27.98 11.96 28.00 12.95 28.02 14.01 28.04 15.11 28.06 16.24 28.08 17.40 28.10 18.60 28.12 19.83 28.14 21.09 28.16 22.39 28.18 23.73 28.20 25.10 28.22 26.35 28.24 27.63 28.26 28.92 28.28 30.24 28.30 31.57 28.32 32.92 28.34 34.29 28.36 35.67 28.38 37.08 28.40 38.50 28.42 39.93 28.44 41.39 28.46 42.86 28.48 44.35 28.50 45.85 28.52 47.37 28.54 48.90 28.56 50.45 28.58 52.02 28.60 53.60 28.62 55.24 28.64 56.89 28.66 58.56 28.68 60.25 28.70 61.95 28.72 63.67 28.74 65.41 28.76 67.17 28.78 68.94 28.80 70.72 28.82 72.44 28.84 74.18 28.86 75.92 28.88 77.68 28.90 79.45 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 ADDRESS TEL WEB PROJECT SHEET 1 OF 8 DATECOMPUTED BYSUBJECTJOB #CHECKED BY OBJECTIVE: REFERENCES: ANALYSIS:The following approach is used to properly size and evaluate each sediment basin: 1. 2.3. CALCULATIONS: - Design for Wet (If Applicable) and Dry Storage: where:A =desired surface area (acres)Q P =peak discharge from design storm (cfs)(NC - Use 10-yr 24-hr storm; GA - Use 2-yr 24-hr storm) (Malcom Eq. III-7) where:S =storage volume (ft3)K S, b =linear regression constants describing the stage-storage relationship Z =stage referenced to the bottom elevation included in the analysis (ft) 14 N. Boylan Avenue, Raleigh, NC 27603 919.828.0577 www.smithgardnerinc.com SR&R Environmental, Inc.8/30/2023LJKSediment Basin Analysis SR&R 23-1 JCL To design a sediment basin(s) to satisfy erosion and sediment control requirements and to handle the flow from the design storm. American Concrete Pipe Association (1996), “Design Data 41 - Manhole Floatation”, ACPA, Irving, TX. Malcom, H. Rooney (1989 & 2003 Supplement), Elements of Urban Stormwater Design, NC State Univ., Raleigh, NC. North Carolina Division of Land Resources (2013 Updates), North Carolina Erosion & Sediment Control Planning & Design Manual, Raleigh, NC. Virginia Department of Conservation and Recreation (1992), Virginia Erosion & Sediment Control Handbook, Third Edition, Richmond, VA. Design for Wet (If Applicable) and Dry Storage. Route Design Storm. Design Outlet Structures (Design Riser/Barrel Structures and Perform Riser Base Calculations, Anti-Seepage Collar Calculations, & Emergency Spillway Calculations). Determine required wet (if applicable) and dry storage volumes based on applicable erosion and sedimentation control requirements. If applicable, calculate the desired surface area at the principal spillway. For some locations: Set up a stage-storage relationship for the proposed basin as shown below. Based on this relationship and the required volume(s) and/or desired surface area, determine the required wet storage (if applicable) and dry storage elevations. Alternatively the elevation(s) can be determined from a graphical stage-storage relationship. Set sediment basin cleanout elevation. A QP=001. S K ZS b= SMITH GARDNER, INC.03 SRR SED BASIN-GENERAL 2018-05-18 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEET 2 OF 8 DATE COMPUTED BY SUBJECT JOB #CHECKED BY (from Original Edition of NCE&SCP&DM) where:A O =surface area of dewatering hole(s) (ft2)AS =surface area of basin (at principal spillway) (ft2)h = Cd =coefficient of contraction (=0.60) T =detention time (hrs.) (vary over recommended limits) - Route Design Storm: Settling Velocity of Design Particle (Malcom Eq. IV-3) where:V o =settling velocity (ft/s) - convert from (m/s) g =gravitational acceleration (m/s2)Ss =specific gravity of design particle ν =kinematic viscosity of the fluid (m2/s)(=1.14 x 10-6m2/s @ 15̊C -Ref.Streeter,1975)d =diameter of design particle (m) Surface Area (Malcom Eq. IV-7) where:As =surface area at given stage (Z) (ft)Ks,b =linear regression constants describing the stage-storage relationship SR&R Environmental, Inc.8/30/2023 LJK Sediment Basin Analysis SR&R 23-1 JCL Size the outlet device to release the dry storage volume (WQV) over the desired drawdown period (typically this is a minimum of 24 hours). Use the following equation: average head of water above hole (= (elev. of principal spillway - elev. of wet storage or (if not applicable) bottom of basin)/2) (ft) Select a standard pipe size and number of holes. Verify that the projected drawdown period is within the recommended limits. Where desired, size a drain for the basin for maintenance. The drain should dewater the basin (to principal spillway) within 24 hours. Use the above equation to determine Ao of the basin drain. The inlet of the drain should be protected from the sediment storage zone. Evaluate basin shape. Compare with the recommended length to width ratio. If this ratio is not achieved, the basin should be modified or baffles should be added as required. Route the design storm through the basin and determine the maximum pool elevation and the peak discharge (via HydroCAD, spreadsheet methods, or other). Depending on local requirements, multiple design storms may need to be considered and the peak discharge may need to be compared with the pre-development value. Based on the peak stage of the design storm, check settling efficiency of the design particle. The design particle is typically 40 microns (0.04 mm) (within silt size criteria). ()A A h TCO S d =2 20 428, ()V g S dO S=-é ëêê ù ûúú18 1 2n ( )A bK ZSS b=-1 SMITH GARDNER, INC.03 SRR SED BASIN-GENERAL 2018-05-18 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEET 3 OF 8 DATE COMPUTED BY SUBJECT JOB #CHECKED BY Settling Efficiency (Malcom Eq. IV-1) where:E =settling efficiency (decimal fraction - convert to %)A S =surface area at given stage (Z) (ft)N =number of effective cells (N = 2 with forebay)Q =discharge at given stage (Z) (cfs) - Design of Outlet Structures: Design Uplift Force (↑F) (from VAE&SCH Spec. 3.14) where:↑F =design uplift force (lbs)FS =factor of safety (use 1.25)VRiser =interior volume of the riser (ft2) (base elevation to principal spillway elevation)γH2O =density of water (62.4 pcf)WRiser buoyant weight of riser (not including base or top) (lbs)WTop =buoyant weight of riser top (lbs)WSoil =buoyant weight of soil backfill around riser (above base projection) (lbs)RSoil =sliding resistance of soil backfill around riser (lbs)* * See American Concrete Pipe Association Design Data 41 for more information. Volume of Concrete for Base (from VAE&SCH Spec. 3.14) where:V Conc =volume of concrete (ft3)W Conc,B =buoyant weight of concrete (150 - 62.4 = 87.6 lbs) Anti-Seepage Collar(s) (VA E&SC Handbook p. III-102) where:Ls =length of pipe in the saturated zone (ft)y =distance from barrel invert to riser crest (ft)z =s = SR&R Environmental, Inc.8/30/2023 LJK Sediment Basin Analysis SR&R 23-1 JCL Design riser/barrel structures based on information used in routing the design storm. Design base for riser structure to resist design uplift force. Base must have a buoyant weight of at least the design uplift force. If a concrete riser structure is used, the buoyant weight of the riser can be accounted for in the calculations. Determine anti-seepage collar requirements based on the following equation. Alternatively, a filter diaphragm may be designed. slope of upstream embankment (zH:1V)pipe slope (ft/ft) E V A NQ O S N = -+é ëê ù ûú - 1 1 ()­=----F FS V W W W RRiser H O Riser Top Soil soilg2 ()V F W F Conc Conc B =­=­ -,.150 624 ()()L y z s sS=++- é ëê ù ûú4 1 025. SMITH GARDNER, INC.03 SRR SED BASIN-GENERAL 2018-05-18 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEET 4 OF 8 DATE COMPUTED BY SUBJECT JOB #CHECKED BY Emergency Spillway (Malcom Eq. I-6) where:Q P =peak discharge from design storm (cfs)C w =weir coefficient (=3.0 for free overfall)L =length of weir (ft)H = SR&R Environmental, Inc.8/30/2023 LJK Sediment Basin Analysis SR&R 23-1 JCL Determine LS and use design chart to determine anti-seepage collar requirements. If more than one collar is used, the spacing between collars should be 14 times the projection (P) of the collar above the barrel. The first collar should be set at 2P from the riser or a minimum length to bury collar in slope. Design crest length of emergency spillway to handle flow from the design storm using the following equation. Determine peak flow from stormwater routing program. If applicable, design outlet channel as a drainage channel or rock chute. driving head (ft) (= allowable headwater above crest of weir or calculated value from stormwater routing program) Q C LHPW=3 2/ SMITH GARDNER, INC.03 SRR SED BASIN-GENERAL 2018-05-18 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYCHECKED BY Basin No.: DESIGN FOR WET (IF APPLICABLE) AND DRY STORAGE: Areas Draining Into Basin: Area Drainage Area (acres) Drainage Area 2.8 Total =2.8 Acres Basin Requirements: Wet Storage: Required Storage Capacity (ft3/Ac.) =0 Enter "0" if Not Applicable. Required Storage Capacity (ft3) =0 Required Depth of Wet Storage (ft) =0.0 Enter "0" if Not Applicable. Dry Storage: Required Storage Capacity (ft3/Ac.) =1,800 To Crest of Principal Spillway Required Storage Capacity (ft3) =5,040 Multipier (X) for Desired Surface Area (Qp x X) =0.01 At Crest of Principal Spillway Peak Discharge into Basin (Qp) (cfs) =18.0 From HydroCAD - 25-Yr, 24-Hr. Storm Desired Surface Area (Ac) =0.18 Desired Surface Area (ft2) =7,854 Determine Stage-Storage Function: Contour Area Area Incremental Cumulative Stage ln S ln Z Z est (ft2)(acres)Volume (ft3)Volume (ft3)(ft) 26.0 22,725 0.52 0 0.0 26.5 24,025 0.55 11,688 11,688 0.5 9.37 -0.69 0.51 27 26,000 0.60 12,506 24,194 1.0 10.09 0.00 0.98 28 30,000 0.69 28,000 52,194 2.0 10.86 0.69 1.99 28.9 32,000 0.73 27,900 80,094 2.9 11.29 1.06 2.94 Linear Regression Constants: Ks =24,640 Storage = 24640 z^1.09 b =1.09 *CAUTION: CHECK INPUT FOR REGRESSION ANALYSIS! SR&R Environmental, Inc.5/8SR&R 23-1Sediment Basin Analysis 4/2/2024LJKJCL Basin 1 26 26 27 27 28 28 29 29 30 0 20,000 40,000 60,000 80,000 100,000 St a g e ( f t ) Storage (cf) Stage-Storage Relationship 26 26 27 27 28 28 29 29 30 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 St a g e ( f t ) Surface Area (sf) Stage-Surface Area Relationship SMITH GARDNER, INC.Basin 1 03 SRR SED BASIN-GENERAL 2018-05-18 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYCHECKED BY Basin Design Elevations: Elev. of Bottom of Basin (ft) =25.5 Wet Storage: Required Storage Capacity (ft3) =0 Min. Elev. of Wet Storage (Permanent Pool) =25.5 Selected Elev. of Wet Storage (Permanent Pool) =26.0 O.K. Actual Wet Storage Volume (ft3) =11,539 O.K. Dry Storage: Required Storage Capacity (ft3) =16,579 = Required Dry Storage + Actual Wet Storage Min. Elev. of Principal Spillway (ft) =26.2 Selected Elev. of Principal Spillway (ft) =26.5 O.K. Actual Total Storage Volume (ft3) =24,640 O.K. Desired Surface Area (ft3) =7,854 Actual Surface Area at Principal Spillway (ft2) =26,968 O.K. Cleanout: Cleanout Requirement (% of Wet Storage) =0 Enter "0" if Not Applicable Cleanout Requirement (% of Total Storage) =50 Basin Cleanout Volume (ft3) =12,320 Based on 50% of Total Storage Volume Basin Cleanout Elevation (ft) =26.0 Dewatering of Dry Storage: Option: Faircloth Skimmer Actual Total Storage Volume to Dewater (ft3) =24,640 = Volume at Principal Spillway Required Orifice Diameter (in) =2.8 From www.fairclothskimmer.com Based on 3 Day Drawdown Basin Drain Calculations: Basin Shape: Length of Basin (ft) =240 Measured at Principal Spillway Elevation Width of Basin (ft) =120 Measured at Principal Spillway Elevation Desired Length to Width Ratio (X:1) =3 Actual Length to Width Ratio (X:1) =2.0 Add Baffles. SR&R Environmental, Inc.6/8SR&R 23-1Sediment Basin Analysis 4/2/2024LJKJCL SMITH GARDNER, INC.Basin 1 03 SRR SED BASIN-GENERAL 2018-05-18 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYCHECKED BY ROUTE DESIGN STORM:Use HydroCAD or Other Method. Design Parameters: Design Storm: 25-Yr, 24-Hr Design Storm Rainfall (in) = 9.01 Rainfall Distribution: Type III Runoff Method: NRCS, HydroCAD Results: Maximum Pool Elevation =27.2 Surface Area at Maximum Pool (ft2) =28,354 Peak Discharge (cfs) =8.2 Check Settling Efficiency: Particle Data: Diam. (microns) =40 Specific Gravity =2.65 Settling Veloc. (ft/s) =0.004140 Reynolds No. (<0.5) =0.044284 O.K. Efficiency Data: Desired Efficiency (%) =80 No. of Effective Cells =3 Settling Efficiency (%) =99.5 O.K. DESIGN OUTLET STRUCTURES: Design Riser/Barrel Structures: Riser Design: Type of Riser: Top of Riser Base Elevation (ft) =25.5 Elev. of Principal Spillway (ft) =26.5 Riser Top Elevation (ft) =26.5 Riser Height (ft) =1.0 Outlets: Outlet No. 1 (for Dewatering Dry Storage):Size: 3" Diam. For Skimmer From Above - Dewatering of Dry Storage Invert Elevation:26.0 May Vary For Multiple Holes Outlet No. 2 (Principal Spillway):Size: 2.5' Wide x 1.0' H Weir (x4) Invert Elevation:26.5 Concrete Riser Wall Thickness (in) =6.0 Riser Inside Length (ft) =5.0 Riser Inside Width (ft) =5.0 Approx. Rect. Concrete Riser Interior Volume (cf) =25 (Top of Base to Principal Spillway) Approx. Rect. Concrete Riser Vol. of Concrete (cf) =11 Barrel Design: Type of Barrel:HDPE Diameter (in) =24 Inv. In Elevation (ft) =25.5 Inv. Out Elevation (ft) =25.3 Length (ft) =35.0 Slope (ft/ft) =0.006 SR&R Environmental, Inc.7/8SR&R 23-1Sediment Basin Analysis 4/2/2024LJKJCL Concrete - Rectangular SMITH GARDNER, INC.Basin 1 03 SRR SED BASIN-GENERAL 2018-05-18 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYCHECKED BY Riser Base Calculations: Design Uplift Force: Factor of Safety =1.25 F (unadjusted) (lbs) =1,950 0 Approx. Rect. Concrete Riser Buoyant Wt. (lbs) =771 Factors in 80% of the Buoyant Weight of the Concrete Riser to Account for Outlets. 0 0 Buoyant Wt. of Riser Top (lbs) =0 4' x 4' x 0.5' x Buoyant Wt. of Concrete (87.6 pcf) Buoyant Wt. of Surrounding Soil Acting on Ext. Base (lbs) =1,200 3' Min. Depth x Outside Perimeter (20') x Base Protrusion (0.5') x Buoyant Wt. of Soil (40 pcf) Sliding Resistance of Surrounding Soil (lbs) =0 F (adjusted) (lbs) =-21 Concrete Base: Required Volume of Concrete (ft3) =-0.2 Length (ft) =4.0 Width (ft) =4.0 Thickness (ft) =0.5 (Includes Concrete Infill Inside of Box) Actual Volume of Concrete (ft3) =8.0 O.K. Anti-Seepage Collar Calculations: (Alternatively - Design Filter Diaphragm) Slope of Upstream Embankment (zH:1V) =3 Slope of Outlet Pipe (ft/ft) =0.006 Ls (ft) =7 Number of Collars:1 Length of Each Collar (ft) =2.0 From Design Chart Based on Ls and No. of Collars Width of Each Collar (ft) =2.0 From Design Chart Based on Ls and No. of Collars Collar Projection, P (ft) =0 Spacing of Subsequent Anti-Seep Collars (ft) =0 = 14P Emergency Spillway Calculations: Crest Elev. (ft) =27.6 Required Freeboard (ft) =1.3 Top of Berm Elev. (ft) =28.9 Required Capacity (cfs) =10.7 From HydroCAD - Clogged Pond Scenario Driving Head (ft) =0.5 Assumed Weir Coefficient =3.0 Length of Crest (ft) =10.1 Determine by Weir Equation* Design Crest Length (ft) =20 * Length = 20 ft minimum. SUMMARY DATA: Basin No.: Basin 1 Elev. of Bottom of Basin (ft) =25.5 Cleanout Elev. (ft) =26.0 Elev. of Wet Storage (Permanent Pool) (ft) =26.0 Elev. of Principal Spillway (ft) =26.5 See Above for Riser and Other Design Information. Emergency Spillway Elev. (ft) =27.6 Top of Berm Elev. (ft) =28.9 Top of Berm Width (ft) =10 Barrel Diameter (in) =24 Barrel Slope (%) =0.6 Sediment Basin Analysis 4/2/2024LJKJCL SR&R Environmental, Inc.8/8SR&R 23-1 SMITH GARDNER, INC.Basin 1 03 SRR SED BASIN-GENERAL 2018-05-18 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 ADDRESS TEL WEB PROJECT SHEET 1 OF 2 DATE COMPUTED BYSUBJECTJOB #CHECKED BY OBJECTIVE: REFERENCES: ANALYSIS: Rip Rap Aprons: 1.Determine the tailwater condition and select the appropriate design chart. 2. 3.Using the same chart, determine apron dimensions. 4.Determine the maximum stone diameter: dmax = 1.5 x d50 5.Determine the apron thickness:Thickness = 1.5 x dmax (No Filter Geotextile) Thickness = 1.5 x d50 (With Filter Geotextile) Other Methods: LJKOutlet Protection Analysis SR&R 23-1 JCL To design outlet protection for culverts and/or drainage channels based on the maximum flow from the design storm. Rip rap aprons are applicable when the Froude Number (Fr) is less than or equal to 2.5 (Debo and Reese). For higher Froude Numbers, rip rap outlet basins, baffled outlets, and/or other methods are more appropriate. Debo, T.N., and Reese, A.J. (1995), Municipal Storm Water Management, Lewis Publishers, Boca Raton, FL, Section 8.11 - pp. 289-290; Section 12.6 - pp. 523-526. 14 N. Boylan Avenue, Raleigh, NC 27603 919.828.0577 www.smithgardnerinc.com SR&R Environmental, Inc.3/28/2024 If Fr > 2.5, consider the use of a rip rap basin, baffled outlet, or other device. Design method according to FHA guidelines using HY8-Energy program (or other documented source). Federal Highway Administration (2000), Hydraulic Design of Energy Dissipators for Culverts and Channels, Hydraulic Engineering Circular No. 14, FHWA EPD-86-110, Metric Ed., U.S. Dept. of Transportation, Washington, D.C. North Carolina Division of Land Resources (2013 Updates), North Carolina Erosion & Sediment Control Planning & Design Manual, Raleigh, NC. For each outlet, determine the Froude Number (Fr) based on the pipe Manning’s number, diameter, slope, and design discharge. Use the methods described in Section 8.11 of Debo and Reese. Select the method of outlet protection, as appropriate, and perform design calculations. If Fr < 2.5, a rip rap apron may be used. The following design approach is based on Section 12.6 of Debo and Reese and Section 8.06 of the NC Erosion & Sediment Control Planning and Design Manual: Using the appropriate design chart, determine the d50 rip-rap size and minimum apron length (La) based on the maximum design flow (Q), flow depth (d), and/or velocity (v) (depending on whether the pipe is flowing full or partially full). SMITH GARDNER, INC.05 SRR OUTLET PROTECTION SG DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEET 2/2JOB #SR&R 23-1SUBJECTDATE3/28/2024COMPUTED BY LJKCHECKED BY JCL Rip Rap Aprons: Basin Pipe Type:CPP Manning's Coefficient:0.018 Diameter (DO) (in) =24 Slope (%) =0.6 Design Discharge (cfs) =8.2 Source of Discharge Data: HydroCAD 25-Yr 24-Hr K =0.201  (degrees) =265 Flow Depth (d) (in) =20.1 Flow Area (ft2) =2.8 Flow Velocity (v) (ft/sec) =2.9 Froude Number =0.39 Yes Low d50 (ft)** =0.50 dmax (ft) =0.75 Apron Thickness (X) (ft):----- No Geotextile:1.13 With Geotextile:0.75 Apron Dimensions (ft):----- Length (La)** =5 Width (W) =7.0 *Tailwater Conditions: Low: Tw < 0.5DO; High: Tw > 0.5DO ** Value from Chart. Tailwater Condition (Low or High)*: Outlet Rip Rap Aprons Applicable? SR&R Environmental, Inc. Outlet Protection Analysis - Rip Rap Aprons (Circular Pipe) SMITH GARDNER, INC.Rip Rap Aprons (Circular Pipe)05 SRR OUTLET PROTECTION SG DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Appendices Rev. 12/93 8.06.3 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 8 8.06.4 Rev. 12/93 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 ADDRESS TEL WEB PROJECT SHEET 1 OF 10 DATECOMPUTED BYSUBJECTJOB #CHECKED BY OBJECTIVE: REFERENCES: ANALYSIS:The following approach is used in the design of drainage channels: 1. 2. 3. 4. 5. 6. CALCULATIONS: - Manning’s Equation: (HEC-22 Eq. 5-5) where:Q =discharge (cfs) n =Manning’s roughness coefficient (See Below) A =cross sectional area of flow (ft2)R =hydraulic radius (ft) = A/PP=wetted perimeterS=slope of channel (ft/ft)V =average channel velocity (ft/sec) Compare the velocity and/or shear stress to allowable values (the maximum slope values will control). If values are exceeded, revise design parameters as required. Based on normal depth values and required freeboard (generally use the greater of 6 inches or 25% of the flow depth), determine the minimum channel depth and top width for both max./min. slopes (the minimum slope values will control). If the channel has a significant curved reach, evaluate the shear stress and superelevation of the water surface in the bend. North Carolina Division of Land Resources (2013 Updates), North Carolina Erosion & Sediment Control Planning & Design Manual, Raleigh, NC. Malcom, H. Rooney (1989 & 2003 Supplement), Elements of Urban Stormwater Design, NC State Univ., Raleigh, NC. Pennsylvania DEP Bureau of Watershed Protection (2000), Erosion and Sediment Pollution Control Program Manual. Determine the peak discharge from the design storm(s) (from HydroCAD or spreadsheet methods). For permanent linings (Grass, TRM, rip rap, gabions, etc.) use the peak discharge from the 25-Yr 24-Hr storm unless otherwise specified. For grass lined channels, a smaller design storm (2-Yr 24-Hr - unless otherwise specified) is used to evaluate temporary linings. Input other design parameters (bottom width; side slopes; minimum freeboard, min./max. slopes; and channel lining). Based on the design parameters calculate normal depth of flow, velocity, Froude number, and maximum shear stress for both max./min. slopes. Also determine the critical slope and corresponding normal depth. JCLDrainage Channel Analysis SR&R-23-1 LJK To design drainage channels, ditches, etc. to handle stormwater flow from the design storm(s). The main design criteria will be to ensure that all drainage channels, ditches, etc. will be able to accommodate the peak discharge from the design storm without overtopping and without exceeding the allowable shear stress and/or velocity of the selected channel lining. Federal Highway Administration (2001), Urban Drainage Design Manual, Hydraulic Engineering Circular No. 22, FHWA NHI-01-021, Second Ed., U.S. Dept. of Transportation, Washington, D.C. 14 N. Boylan Avenue, Raleigh, NC 27603 919.828.0577 www.smithgardnerinc.com SR&R Environmental, Inc.1/31/2024 Q AR S n AV==149 2 3 1 2.// SMITH GARDNER, INC.06 SRR Drainage Channel_JCL DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEET 2 OF 10 DATE COMPUTED BY SUBJECT JOB #CHECKED BY - Maximum Shear Stress (Tractive Force Method): (HEC-22 Eq. 5-13) where:τd =maximum shear stress on channel lining (psf) γ =unit weight of water (62.4 pcf)d =maximum depth of flow (ft)S =channel slope (ft/ft) - Froude Number: where:Fr =Froude number (dimensionless) v =flow velocity (ft/sec)g =acceleration of gravity (32.2 ft/sec2) A =cross-sectional area of flow (ft2) T =top width of flow (ft) Critical Slope: - Manning’s Roughness Coefficient (n): Grass: (HEC-22 Eq. 5-6 - 5-10) where:R =hydraulic radius (ft)K =vegetative coefficient (depending on retardance class)= 15.8 (Class A) = 23.0 (Class B) = 30.2 (Class C)= 34.6 (Class D)= 37.7 (Class E)S =slope of channel (ft/ft) Rip Rap: (PA DEP Manual Fig. 3) where:y =depth of flow (ft)d 50 =median size of rip rap (ft) Drainage Channel Analysis SR&R-23-1 LJK Note that A/T = the hydraulic depth (D). For Fr > 1.0, flow is supercritical; Fr < 1.0, flow is subcritical; Fr = 1.0, flow is critical. The critical slope (Sc) is the slope at which Fr = 1.0. When the slope is between 0.7Sc and 1.3Sc , unstable flow may occur as small flow disturbances can initiate a change in the flow state. If slopes are within this range, consider additional freeboard. SR&R Environmental, Inc.1/31/2024 JCL t gddS= Fr v gA T = ()[]n R K R S=+ 1 6 14 0 41997 / ... log n y y d =æ èç ö ø÷ + 1 6 50 216 14 / . log SMITH GARDNER, INC.06 SRR Drainage Channel_JCL DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEET 3 OF 10 DATE COMPUTED BY SUBJECT JOB #CHECKED BY - Curved Channels (Where Applicable): Shear Stress in Bend: (HEC-22 Eq. 5-15) where:τ d =bend shear stress (psf)K b =function of Rc/B (use HEC-22 Chart 21) τ d =maximum shear stress on channel lining (psf)R c =radius to the centerline of the channel (ft) B =bottom width of channel (ft) Superelevation at Outside of Bend: (HEC-22 Eq. 5-11 modified) where:Dd = V =average channel velocity (ft/sec) T =top width of flow (ft) g =acceleration of gravity (32.2 ft/sec2)R c =radius to the centerline of the channel (ft) - Allowable Shear Stress/Velocity: Grass-Lined Channels: Class A:3.7Class B:2.1Class C:1Class D:0.6 Class E:0.35 Rip Rap-Lined Channels: (HEC-22 Eq. 5-17) where:τallow =allowable shear stress (psf)d 50 =median size of rip rap (ft) For rip rap-lined channels, an allowable velocity approach is applicable for slopes flatter than 10% (see table below). For slopes of 10% or steeper, use the following equation: JCL Drainage Channel Analysis SR&R-23-1 LJK superelevation of water surface between the outer channel bank and the centerline of the channel (avg. water surface before bend) (ft) For grass-lined channels, an allowable velocity approach is applicable for slopes flatter than 10%. For slopes of 10% and steeper appropriate permanent linings should be used. For use in the evaluation of curved channels, the following allowable shear stress values (lb/ft2) can be assumed based on retardance class: SR&R Environmental, Inc.1/31/2024 t tbb dK= Dd V T gRc =05 2 . tallow d=´4 50 SMITH GARDNER, INC.06 SRR Drainage Channel_JCL DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEET 4 OF 10 DATE COMPUTED BY SUBJECT JOB #CHECKED BY Ref: PA DEP Manual Table 9 Reno Mattress or Gabion-Lined Channels: Ref: PA DEP Manual Table 13 For Reno mattress or gabion-lined channels, use allowable velocity for slopes flatter than 10% and allowable shear stress for slopes of 10% or steeper (see table below). SR&R Environmental, Inc.1/31/2024 JCL Drainage Channel Analysis SR&R-23-1 LJK SMITH GARDNER, INC.06 SRR Drainage Channel_JCL DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYChannel No.CHECKED BY Design Parameters: PEAK DISCHARGE,Q25 =10.7 ft3/s Source: HydroCAD 100-Yr 24-Hr Bottom Width,B =20.0 ft Rip Rap Lining: Left Side Slope,z1 =2.0 horizontal :1 vertical D50 =0.50 ft Right Side Slope,z2 =2.0 horizontal :1 vertical Vallow =10.0 ft/sec tallow =2.0 lb/ft2 Minimum Freeboard =1.0 ft Maximum Channel Slope,S max =0.050 ft/ft Minimum Channel Slope,Smin =0.030 ft/ft Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Average Flow Froude Maximum Allowable Factor (Norm. Depth) Roughness of Flow Perimeter Radius Width Depth Velocity Rate Number Shear Stress Velocity (V) or of Safety Yn Coefficient A P R=A/P T D=A/T Vn Q F r (Normal)td Sh. Stress (S)vallow/vn or ft n ft2 ft ft ft ft ft/s ft3/s #lb/ft2 Used?tallow/td Maximum Slope: 0.31 0.086 6.39 21.39 0.30 21.24 0.30 1.72 11.0 0.55 1.0 V 5.8 Minimum Slope: 0.34 0.080 7.03 21.52 0.33 21.36 0.33 1.52 10.7 0.47 0.6 V 6.6 Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Section Flow Average Froude Uniform-Flow (Crit. Depth) Roughness of Flow Perimeter Radius Width Depth Factor Rate Velocity Number Critical Slope Yc Coefficient A P R=A/P T D=A/T Z=AD1/2 Q Vc Fr (Critical)Sc ft n ft2 ft ft ft ft ft2.5 ft3/s ft/s #ft/ft 0.21 0.132 4.29 20.94 0.20 20.84 0.21 1.95 11.0 2.57 1.00 0.428 Minimum Minimum Minimum Minimum Channel Top Width Channel Top Width Depth T Depth T ft ft ft ft 1.31 25.24 1.34 25.36 Comment Flow is Stable. Determination of Minimum Channel Depth & Top Width Maximum Slope Minimum Slope LJK Normal Depth Comment O.K. O.K. Critical Depth Emergency Spillway (Clogged Pond) SR&R Environmental, Inc.5/10SR&R-23-1Drainage Channel Analysis (Rip Rap Lined)3/18/2024JCL SMITH GARDNER, INC.Rip Rap (Emergency Spillway)06 SRR Drainage Channel_JCL DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYChannel No.CHECKED BY Design Parameters: PEAK DISCHARGE,Q2 =6.7 ft3/s Source: HydroCAD 2-Yr, 24-Hr Storm PEAK DISCHARGE,Q25 =15.8 ft3/s Source: HydroCAD 25-Yr, 24-Hr Storm Bottom Width,B =6.0 ft Permanent Grass Lining:Temporary Lining: Left Side Slope,z1 =2.0 horizontal :1 vertical Grass Retardance =D Temporary Lining Used (Y/N) =Y Right Side Slope,z2 =2.0 horizontal :1 vertical K = 34.6 RECP Product Name = NA Green - Curlex I, or equal Vallow =4.5 ft/sec Manning's Coefficient,n =0.035 Minimum Freeboard =0.5 ft tallow =0.60 lb/ft2 tallow = 1.55 lb/ft2 Maximum Channel Slope,Smax = 0.010 ft/ft Bare Ground (If Temporary Liner Not Used): Minimum Channel Slope,Smin = 0.005 ft/ft Manning's Coefficient,n =0.020 Vallow =2.0 ft/sec Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Average Flow Froude Maximum Allowable Factor (Norm. Depth) Roughness of Flow Perimeter Radius Width Depth Velocity Rate Number Shear Stress Velocity (V) or of Safety Yn Coefficient A P R=A/P T D=A/T Vn Q Fr (Normal)td Sh. Stress (S)vallow/vn or ft n ft2 ft ft ft ft ft/s ft3/s #lb/ft2 Used?tallow/td Maximum Slope: 0.44 0.035 3.03 7.97 0.38 7.76 0.39 2.23 6.8 0.63 0.3 S 5.6 Minimum Slope: 0.53 0.035 3.74 8.37 0.45 8.12 0.46 1.76 6.6 0.46 0.2 S 9.4 Maximum Slope: 0.99 0.062 7.90 10.43 0.76 9.96 0.79 1.98 15.7 0.39 0.6 V 2.3 Minimum Slope: 1.23 0.065 10.41 11.50 0.90 10.92 0.95 1.51 15.7 0.27 0.4 V 3.0 Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Section Flow Average Froude Uniform-Flow (Crit. Depth) Roughness of Flow Perimeter Radius Width Depth Factor Rate Velocity Number Critical Slope Yc Coefficient A P R=A/P T D=A/T Z=AD1/2 Q Vc Fr (Critical)Sc ft n ft2 ft ft ft ft ft2.5 ft3/s ft/s #ft/ft 0.32 0.035 2.12 7.43 0.29 7.28 0.29 1.15 6.5 3.07 1.00 0.028 0.56 0.056 3.99 8.50 0.47 8.24 0.48 2.77 15.7 3.95 1.00 0.060 Minimum Minimum Minimum Minimum Channel Top Width Channel Top Width Depth T Depth T ft ft ft ft 1.49 11.96 1.73 12.92 Maximum Slope Minimum Slope Comment Q2 Flow is Stable. Q25 Flow is Stable. Determination of Minimum Channel Depth & Top Width (Based on Q25) O.K. O.K. Q25 O.K. O.K. Critical Depth LJK Normal Depth Comment Q2 Jurisdictional Ditch (Pre-Construction) SR&R Environmental, Inc.6/10SR&R-23-1Drainage Channel Analysis (Grass Lined)4/29/2024JCL SMITH GARDNER, INC.Juris Ditch PreCon 06 SRR Drainage Channel_JCL DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYChannel No.CHECKED BY Design Parameters: PEAK DISCHARGE,Q2 =15.2 ft3/s Source: HydroCAD 2-Yr, 24-Hr Storm PEAK DISCHARGE,Q25 =40.6 ft3/s Source: HydroCAD 25-Yr, 24-Hr Storm Bottom Width,B =8.0 ft Permanent Grass Lining:Temporary Lining: Left Side Slope,z1 =1.0 horizontal :1 vertical Grass Retardance =D Temporary Lining Used (Y/N) =Y Right Side Slope,z2 =1.0 horizontal :1 vertical K = 34.6 RECP Product Name = NA Green - Curlex I, or equal Vallow =4.5 ft/sec Manning's Coefficient,n =0.035 Minimum Freeboard =0.5 ft tallow =0.60 lb/ft2 tallow = 1.55 lb/ft2 Maximum Channel Slope,Smax = 0.010 ft/ft Bare Ground (If Temporary Liner Not Used): Minimum Channel Slope,Smin = 0.003 ft/ft Manning's Coefficient,n =0.020 Vallow =2.0 ft/sec Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Average Flow Froude Maximum Allowable Factor (Norm. Depth) Roughness of Flow Perimeter Radius Width Depth Velocity Rate Number Shear Stress Velocity (V) or of Safety Yn Coefficient A P R=A/P T D=A/T Vn Q Fr (Normal)td Sh. Stress (S)vallow/vn or ft n ft2 ft ft ft ft ft/s ft3/s #lb/ft2 Used?tallow/td Maximum Slope: 0.62 0.035 5.34 9.75 0.55 9.24 0.58 2.85 15.2 0.66 0.4 S 4.0 Minimum Slope: 0.89 0.035 7.91 10.52 0.75 9.78 0.81 1.93 15.3 0.38 0.2 S 9.3 Maximum Slope: 1.40 0.051 13.16 11.96 1.10 10.80 1.22 3.09 40.6 0.49 0.9 V 1.5 Minimum Slope: 2.07 0.055 20.84 13.85 1.50 12.14 1.72 1.94 40.5 0.26 0.4 V 2.3 Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Section Flow Average Froude Uniform-Flow (Crit. Depth) Roughness of Flow Perimeter Radius Width Depth Factor Rate Velocity Number Critical Slope Yc Coefficient A P R=A/P T D=A/T Z=AD1/2 Q Vc Fr (Critical)Sc ft n ft2 ft ft ft ft ft2.5 ft3/s ft/s #ft/ft 0.47 0.035 3.98 9.33 0.43 8.94 0.45 2.66 15.1 3.79 1.00 0.025 0.89 0.048 7.91 10.52 0.75 9.78 0.81 7.12 40.4 5.10 1.00 0.039 Minimum Minimum Minimum Minimum Channel Top Width Channel Top Width Depth T Depth T ft ft ft ft 1.90 11.80 2.57 13.14 SR&R Environmental, Inc.7/10SR&R-23-1Drainage Channel Analysis (Grass Lined)1/31/2024JCLWest Easement Ditch (Pre-Construction)LJK Normal Depth Comment Q2 O.K. O.K. Q25 O.K. O.K. Critical Depth Comment Q2 Flow is Stable. Q25 Flow is Stable. Determination of Minimum Channel Depth & Top Width (Based on Q25) Maximum Slope Minimum Slope SMITH GARDNER, INC.Western Easement (PreCon)06 SRR Drainage Channel_JCL DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYChannel No.CHECKED BY Design Parameters: PEAK DISCHARGE,Q2 =17.2 ft3/s Source: HydroCAD 2-Yr, 24-Hr Storm PEAK DISCHARGE,Q25 =45.6 ft3/s Source: HydroCAD 25-Yr, 24-Hr Storm Bottom Width,B =8.0 ft Permanent Grass Lining:Temporary Lining: Left Side Slope,z1 =1.0 horizontal :1 vertical Grass Retardance =D Temporary Lining Used (Y/N) =Y Right Side Slope,z2 =1.0 horizontal :1 vertical K = 34.6 RECP Product Name = NA Green - Curlex I, or equal Vallow =4.5 ft/sec Manning's Coefficient,n =0.035 Minimum Freeboard =0.5 ft tallow =0.60 lb/ft2 tallow = 1.55 lb/ft2 Maximum Channel Slope,Smax = 0.010 ft/ft Bare Ground (If Temporary Liner Not Used): Minimum Channel Slope,Smin = 0.003 ft/ft Manning's Coefficient,n =0.020 Vallow =2.0 ft/sec Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Average Flow Froude Maximum Allowable Factor (Norm. Depth) Roughness of Flow Perimeter Radius Width Depth Velocity Rate Number Shear Stress Velocity (V) or of Safety Yn Coefficient A P R=A/P T D=A/T Vn Q Fr (Normal)td Sh. Stress (S)vallow/vn or ft n ft2 ft ft ft ft ft/s ft3/s #lb/ft2 Used?tallow/td Maximum Slope: 0.67 0.035 5.81 9.90 0.59 9.34 0.62 2.98 17.3 0.67 0.4 S 3.7 Minimum Slope: 0.96 0.035 8.60 10.72 0.80 9.92 0.87 2.01 17.3 0.38 0.2 S 8.6 Maximum Slope: 1.48 0.050 14.03 12.19 1.15 10.96 1.28 3.25 45.6 0.51 0.9 V 1.4 Minimum Slope: 2.19 0.054 22.32 14.19 1.57 12.38 1.80 2.04 45.6 0.27 0.4 V 2.2 Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Section Flow Average Froude Uniform-Flow (Crit. Depth) Roughness of Flow Perimeter Radius Width Depth Factor Rate Velocity Number Critical Slope Yc Coefficient A P R=A/P T D=A/T Z=AD1/2 Q Vc Fr (Critical)Sc ft n ft2 ft ft ft ft ft2.5 ft3/s ft/s #ft/ft 0.51 0.035 4.34 9.44 0.46 9.02 0.48 3.01 17.1 3.94 1.00 0.024 0.96 0.047 8.60 10.72 0.80 9.92 0.87 8.01 45.5 5.28 1.00 0.037 Minimum Minimum Minimum Minimum Channel Top Width Channel Top Width Depth T Depth T ft ft ft ft 1.98 11.96 2.69 13.38 SR&R Environmental, Inc.8/10SR&R-23-1Drainage Channel Analysis (Grass Lined)4/29/2024JCLWest Easement Ditch (Pre-Construction)LJK Normal Depth Comment Q2 O.K. O.K. Q25 O.K. O.K. Critical Depth Comment Q2 Flow is Stable. Q25 Flow is Stable. Determination of Minimum Channel Depth & Top Width (Based on Q25) Maximum Slope Minimum Slope SMITH GARDNER, INC.Western Easement (PostCon)06 SRR Drainage Channel_JCL DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYChannel No.CHECKED BY Design Parameters: PEAK DISCHARGE,Q2 =4.6 ft3/s Source: HydroCAD 2-Yr, 24-Hr Storm PEAK DISCHARGE,Q25 =12.6 ft3/s Source: HydroCAD 25-Yr, 24-Hr Storm Bottom Width,B =3.0 ft Permanent Grass Lining:Temporary Lining: Left Side Slope,z1 =3.0 horizontal :1 vertical Grass Retardance =D Temporary Lining Used (Y/N) =Y Right Side Slope,z2 =3.0 horizontal :1 vertical K = 34.6 RECP Product Name = NA Green - Curlex I, or equal Vallow =4.5 ft/sec Manning's Coefficient,n =0.035 Minimum Freeboard =0.5 ft tallow =0.60 lb/ft2 tallow = 1.55 lb/ft2 Maximum Channel Slope,Smax = 0.010 ft/ft Bare Ground (If Temporary Liner Not Used): Minimum Channel Slope,Smin = 0.002 ft/ft Manning's Coefficient,n =0.020 Vallow =2.0 ft/sec Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Average Flow Froude Maximum Allowable Factor (Norm. Depth) Roughness of Flow Perimeter Radius Width Depth Velocity Rate Number Shear Stress Velocity (V) or of Safety Yn Coefficient A P R=A/P T D=A/T Vn Q Fr (Normal)td Sh. Stress (S)vallow/vn or ft n ft2 ft ft ft ft ft/s ft3/s #lb/ft2 Used?tallow/td Maximum Slope: 0.49 0.035 2.19 6.10 0.36 5.94 0.37 2.15 4.7 0.62 0.3 S 5.1 Minimum Slope: 0.74 0.035 3.86 7.68 0.50 7.44 0.52 1.20 4.7 0.29 0.1 S 16.8 Maximum Slope: 1.11 0.066 7.03 10.02 0.70 9.66 0.73 1.79 12.6 0.37 0.7 V 2.5 Minimum Slope: 1.73 0.076 14.17 13.94 1.02 13.38 1.06 0.89 12.6 0.15 0.2 V 5.1 Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Section Flow Average Froude Uniform-Flow (Crit. Depth) Roughness of Flow Perimeter Radius Width Depth Factor Rate Velocity Number Critical Slope Yc Coefficient A P R=A/P T D=A/T Z=AD1/2 Q Vc Fr (Critical)Sc ft n ft2 ft ft ft ft ft2.5 ft3/s ft/s #ft/ft 0.37 0.035 1.52 5.34 0.28 5.22 0.29 0.82 4.7 3.06 1.00 0.028 0.65 0.057 3.22 7.11 0.45 6.90 0.47 2.20 12.5 3.87 1.00 0.063 Minimum Minimum Minimum Minimum Channel Top Width Channel Top Width Depth T Depth T ft ft ft ft 1.61 12.66 2.23 16.38 SR&R Environmental, Inc.9/10SR&R-23-1Drainage Channel Analysis (Grass Lined)4/29/2024JCLOn-Site Channel to West Easement LJK Normal Depth Comment Q2 O.K. O.K. Q25 O.K. O.K. Critical Depth Comment Q2 Flow is Stable. Q25 Flow is Stable. Determination of Minimum Channel Depth & Top Width (Based on Q25) Maximum Slope Minimum Slope SMITH GARDNER, INC.DC to WDE (Post Con)06 SRR Drainage Channel_JCL DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYChannel No.CHECKED BY Design Parameters: PEAK DISCHARGE,Q2 =7.6 ft3/s Source: HydroCAD 2-Yr, 24-Hr Storm PEAK DISCHARGE,Q25 =18.5 ft3/s Source: HydroCAD 25-Yr, 24-Hr Storm Bottom Width,B =4.0 ft Permanent Grass Lining:Temporary Lining: Left Side Slope,z1 =1.0 horizontal :1 vertical Grass Retardance =D Temporary Lining Used (Y/N) =Y Right Side Slope,z2 =1.0 horizontal :1 vertical K = 34.6 RECP Product Name = NA Green - Curlex I, or equal Vallow =4.5 ft/sec Manning's Coefficient,n =0.035 Minimum Freeboard =0.5 ft tallow =0.60 lb/ft2 tallow = 1.55 lb/ft2 Maximum Channel Slope,Smax = 0.010 ft/ft Bare Ground (If Temporary Liner Not Used): Minimum Channel Slope,Smin = 0.005 ft/ft Manning's Coefficient,n =0.020 Vallow =2.0 ft/sec Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Average Flow Froude Maximum Allowable Factor (Norm. Depth) Roughness of Flow Perimeter Radius Width Depth Velocity Rate Number Shear Stress Velocity (V) or of Safety Yn Coefficient A P R=A/P T D=A/T Vn Q Fr (Normal)td Sh. Stress (S)vallow/vn or ft n ft2 ft ft ft ft ft/s ft3/s #lb/ft2 Used?tallow/td Maximum Slope: 0.62 0.035 2.86 5.75 0.50 5.24 0.55 2.67 7.7 0.64 0.4 S 4.0 Minimum Slope: 0.76 0.035 3.62 6.15 0.59 5.52 0.66 2.11 7.6 0.46 0.2 S 6.5 Maximum Slope: 1.36 0.056 7.29 7.85 0.93 6.72 1.08 2.54 18.5 0.43 0.8 V 1.8 Minimum Slope: 1.70 0.059 9.69 8.81 1.10 7.40 1.31 1.92 18.6 0.30 0.5 V 2.3 Depth of Flow Manning's Area Wetted Hydraulic Top Hydraulic Section Flow Average Froude Uniform-Flow (Crit. Depth) Roughness of Flow Perimeter Radius Width Depth Factor Rate Velocity Number Critical Slope Yc Coefficient A P R=A/P T D=A/T Z=AD1/2 Q Vc Fr (Critical)Sc ft n ft2 ft ft ft ft ft2.5 ft3/s ft/s #ft/ft 0.46 0.035 2.05 5.30 0.39 4.92 0.42 1.32 7.5 3.66 1.00 0.026 0.81 0.050 3.90 6.29 0.62 5.62 0.69 3.24 18.4 4.72 1.00 0.048 Minimum Minimum Minimum Minimum Channel Top Width Channel Top Width Depth T Depth T ft ft ft ft 1.86 7.72 2.20 8.40 SR&R Environmental, Inc.10/10SR&R-23-1Drainage Channel Analysis (Grass Lined)4/29/20243NCDOT R/W Ditch (Pre-Construction)LJK Normal Depth Comment Q2 O.K. O.K. Q25 O.K. O.K. Critical Depth Comment Q2 Flow is Stable. Q25 Flow is Stable. Determination of Minimum Channel Depth & Top Width (Based on Q25) Maximum Slope Minimum Slope SMITH GARDNER, INC.NCDOT ROW PreCon 06 SRR Drainage Channel_JCL DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 ADDRESS TEL WEB PROJECT SHEET 1 OF 2 DATE COMPUTED BY SUBJECT JOB #CHECKED BY OBJECTIVE: REFERENCE: ANALYSIS: 1. 2.Input Culvert Parameters: HW A =allowable headwater depth (ft) N =number of pipes used Q PIPE =peak discharge /N (cfs) D =culvert diameter (in) Type of Culvert (i.e., Concrete, CMP, etc.) L =culvert length (ft) s =culvert slope (ft/ft) n =Manning’s number ke =entrance loss coefficient d c =critical depth (use critical depth figures) (ft) CALCULATIONS: - Inlet Control: A.Enter Inlet Control Nomograph with D & QPIPE and find HW/D for the proper entrance type. B.Compute HW . If HW exceeds HW A , try larger culvert. - Outlet Control: A.Enter outlet control nomograph with L , Ke , & D . B. where:or tailwater depth, whichever is greater. C.If HW exceeds HW A , try larger culvert. 14 N. Boylan Avenue, Raleigh, NC 27603 919.828.0577 www.smithgardnerinc.com SR&R Environmental - 220 Crowatan 4/26/2024 Debo, T.N., and Reese, A.J., Municipal Storm Water Management, Lewis Publishers, Boca Raton, FL, 1995, p. 333. The following approach is used in the design of culverts (after Debo and Reese): Determine the peak discharge from the design storm(s) (from HydroCAD or spreadsheet methods). Use the peak discharge from the 25-Yr 24-Hr storm unless otherwise specified. To compute HW, connect the length scale for the type of entrance condition and culvert diameter scale with a straight line, pivot on the turning line, and draw a straight line from the design discharge through the turning point to the head loss scale H. Compute HW from the following equation: JCL Culvert Analysis SR&R-23-1 LJK To design culverts to handle stormwater flow from the design storm(s). The main design criteria will be to ensure that all culverts will be able to accommodate the peak discharge from the design storm without exceeding the allowable headwater depth. SMITH GARDNER, INC.07 CULVERT SG DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYCHECKED BY Culvert No.:Proposed Driveway Pipe Peak Discharge: PEAK DISCHARGE, Q25 (cfs) =18.5 Source:HydroCAD 25-Yr 24-Hr Storm Culvert Parameters: Allowable HW Depth (ft) =3 Number of Pipes, N =1 Qpipe (cfs) =18.5 Culvert Diameter, D (in) =24 Type of Culvert =RCP Invert In Elev. (ft) =25.0 Invert Out Elev. (ft) =25.0 Culvert Length, L (ft) =84 Culvert Slope, S (ft/ft) =0.0001 Manning's Number, n =0.011 Entrance Loss Coef., ke =0.5 Critical Depth (ft) =1.5 Tailwater Depth (ft) =0.0 Case 1: Inlet Control HW/D =1.4 (From Inlet Control Nomograph)HW (ft) =2.8 INLET CONTROL GOVERNS! LJK SR&R Environmental - 220 Crowatan Road 2/2SR&R-23-1Culvert Analysis 4/26/2024JCL SMITH GARDNER, INC.C-1 07 CULVERT SG DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 ADDRESS TEL WEB PROJECT SHEET 1 OF 4 DATECOMPUTED BYSUBJECTJOB #CHECKED BY OBJECTIVE: REFERENCES: ANALYSIS: 1. Positive Projecting Embankment Soil Load: (CPDM Eqn. 4.1) (CPDM Eqn. 4.2) where:WE =earth load, (lbs/LF) VAF =vertical arching factor (CPDM Illustration 4.7)PL =prism load, (lbs/LF)gs =average unit weight of soil cover (lbs/ft3) H =height of backfill over top of pipe (ft)DO =outside diameter of pipe (ft) (given in CPDM Table 42). Trench Soil Load: (CPDM Eqn. 4.3) (CPDM Eqn. 4.4) where:W d =fill load for trench condition, (lbs/LF)C d =trench load coefficientgs=average unit weight of soil cover (lbs/ft3) B d =width of trench (ft)DO =outside diameter of pipe (ft) (given in CPDM Table 42).H =height of backfill over top of pipe (ft)K =ratio of active lateral unit pressure to vertical unit pressurem'=tan f', coefficient of friction between fill material and sides of trench The analysis is based on the following procedure recommended by the American Concrete Pipe Association (ACPA). Note that the design parameters will vary depending on what condition the pipe is installed (trench, positive projecting embankment, negative projecting embankment, or jacked/tunneled). Determination of Earth Load, WE: Based on the assumed concrete pipe parameters (size, backfill, etc.) use the tables and figures in the Concrete Pipe Design Manual (CPDM) to determine the earth load acting on the pipe or the following equations. Note that the values determined in the tables and figures are based on a backfill unit weight of 100 lbs/ft3. This value must be adjusted for the anticipated backfill unit weight. Also, for a negative projecting embankment condition, values for projection ratio, p' (vertical distance between the top of the pipe and natural ground divided by the trench width), and settlement ratio, rsd, must be determined in order to use the figures. Table 40 of the CPDM gives suggested values for rsd based on the value of p'. 14 N. Boylan Avenue, Raleigh, NC 27603 919.828.0577 www.smithgardnerinc.com SR&R Environmental, Inc.4/29/2024 To determine the loads acting on each concrete pipe and evaluate the required pipe strength. Select the appropriate class of pipe to satisfy the strength requirement. American Concrete Pipe Association (2011), Concrete Pipe Design Manual, ACPA, Vienna, VA. American Society for Testing and Materials, “ASTM C 76 - Standard Specification for Reinforced Concrete Culvert, Storm Drain, & Sewer Pipe”, ASTM, Philadelphia. LJKConcrete Pipe Strength Analysis SR&R 23-1 JCL W VAFxPLE= ()PL H D DS O O=+-é ëê ù ûúgp4 8 ()W C B D d d S d O S=+-g p g2 2 4 8 C e Kd K H Bd=--1 2 2 m m ' ' SMITH GARDNER, INC.08 SRR CONCRETE PIPE SGV2 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEET 2 OF 4 DATE COMPUTED BY SUBJECT JOB #CHECKED BY Per the CPDM:K m '=0.1924 max. for granular materials without cohesionKm'=0.165 max. for sand and gravelKm'=0.150 max. for saturated top soilKm'=0.130 max. for ordinary clayKm'=0.110 max. for saturated clay 2. 3. 4. where:B fv =variable bedding factor, trenchBfe=bedding factor, embankment (CPDM Illustration 4.22)Bfo =minimum bedding factor, trench (CPDM Illustration 4.23)B d =trench width at top of pipe (ft)Bc =outside horizontal span of pipe (ft)Bdt =transition width at top of pipe (ft) (given in CPDM Tables 13-39). Use CPDM Illustration 4.25 to determine the live load bedding factor, BfLL. 5. 6. where:WE =earth load on pipe (lbs/linear ft)W F =fluid load on pipe (lbs/linear ft) (=gw x Apipe= 62.4 lbs/ft3 x pD2/4)W L =live load on pipe (lbs/linear ft)B f =bedding factor=Bfefor embankment installations =Bfv for trench installationsBfLL=live load bedding factor FS =factor of safetyD=pipe diameter (ft) Concrete Pipe Strength Analysis SR&R 23-1 JCL Determination of Bedding Factors: Determine the bedding factors based on the guidance given in the CPDM. For embankment installations, the bedding factor, Bfe, is found from Illustration 4.22 of the CPDM depending on the selected Standard Installation. For trench installations the bedding factor is based on the following equation: (CPDM Eqn. 4.22) LJK Selection of Installation Type: Select the Standard Installation based on the guidance given in the CPDM. Note that a Type 1 Standard Installation requires the highest construction quality and degree of inspection while a Type 4 Standard Installation requires virtually no construction quality or inspection. Determination of Live Load, WL: Based on the concrete pipe parameters (size, backfill, etc.) use the tables in the CPDM to determine the live load acting on the pipe. Note that the values for backfill heights of 10 feet or more and considered insignificant to the design of the pipe. 4/29/2024 Application of Factor of Safety, FS: According to the ACPA, a factor of safety of 1.0 should be applied if the 0.01-inch crack strength is used as the design criterion rather than the ultimate strength. Selection of Pipe Strength/Class:The required three-edge bearing strength of circular reinforced concrete pipe is expressed as Dload in the following equation: (CPDM Eqn. 4.24) SR&R Environmental, Inc. ()() ()B B B B B B B Bfv fe fo d c dt c fo=-- -+ D W W B W B FS DLoadEF f L fLL =++é ëêê ù ûúú+ SMITH GARDNER, INC.08 SRR CONCRETE PIPE SGV2 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEET 3 OF 4 DATE COMPUTED BY SUBJECT JOB #CHECKED BY Select class of reinforced concrete pipe based on the following ASTM C-76 guidelines: V 3,000 II 1,000 III 1,350IV2,000 Note that if BfLL is greater than Bfe for embankment installations or Bfv for trench installations, use Bfe or Bfv in place of BfLL. Maximum D LoadFor 0.01-inch CrackPipe Class (lb/lf/ft of diameter) I 800 LJK Concrete Pipe Strength Analysis SR&R 23-1 JCL SR&R Environmental, Inc.4/29/2024 SMITH GARDNER, INC.08 SRR CONCRETE PIPE SGV2 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 PROJECT SHEETJOB #SUBJECT DATECOMPUTED BYCHECKED BY Culvert No.:C-1 Concrete Pipe Parameters: Type of Pipe =Circular, ConcretePipe Diameter, D (in) =24 Outside Horizontal Span, Bc (ft) (= DO) =2.50 (From CPDM Table 42) Height of Backfill,H (ft) =1.0 Backfill Type =Sand & Gravel Backfill Unit Wt. (lbs/ft3) =110 Standard Installation =Type 4Trench Width,Bd (ft) =5.0 Must be < transition width. Otherwise, treat as Embankment Installation. Transition Width,Bdt (ft) =7.0 (From CPDM - Table 23) Km'0.150 (conservative for sand & gravel backfill) Determine Earth and Fluid Loads: Cd (lbs/LF) =0.19 Wd (lbs/LF) =608 WF (lbs/LF) =196 Determine Live Load: W L (lbs/LF) =3,010 (From CPDM Table 42) Determine Bedding Factors: Embankment Bedding Factor,Bfe =1.7 (From CPDM Illustration 4.22) Min. Trench Bedding Factor,Bfo =1.5 (From CPDM Illustration 4.23) Variable Trench Bedding Factor,B fv =1.6 Live Load Bedding Factor, BfLL =2.2 (From CPDM Illustration 4.25) Factor of Safety: Factor of Safety,FS =1.00 (Use 1.0 for Reinforced; 1.25 to 1.5 for Non-Reinforced) Selection of Required Pipe Strength/Class: D Load (lbs/LF/ft) =1,184 Pipe Class Max. D-Load I 800II1,000 III 1,350 Use Class III RCP IV 2,000 V 3,000 JCL (Table per ASTM C 76) SR&R Environmental, Inc.4/4SR&R 23-1Concrete Pipe Strength Analysis 4/29/2024(Trench Condition)LJK SMITH GARDNER, INC.Trench 08 SRR CONCRETE PIPE SGV2 DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 Technical Specifications SR&R Environmental – Laydown Yard Castle Hayne, North Carolina Prepared for: SR&R Environmental, Inc. Wilmington, North Carolina October 2023 © 2023 Smith Gardner, Inc. This document is intended for the sole use of the client for which it was prepared and for the purpose agreed upon by the client and Smith Gardner, Inc. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 This page intentionally left blank. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Table of Contents Page i SR&R Environmental – Laydown Yard Castle Hayne, North Carolina Technical Specifications Table of Contents Section Specification 02110 Site Preparation 02222 Excavation 02223 Embankment 02240 Geotextiles 02270 Erosion and Sedimentation Control 02271 Rip Rap 02275 Rolled Erosion Control Products 02608 Precast Concrete Structures 02720 Stormwater Systems 02930 Revegetation DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 This page intentionally left blank. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Site Preparation Page 02110-1 SECTION 02110 SITE PREPARATION A. Description 1. General: a. The Contractor shall furnish all labor, material, and equipment to complete Site Preparation in accordance with the Contract Drawings and these Specifications. b. Principal items of work include: 1. Notifying all authorities owning utility lines running to or on the property. Protect and maintain all utility lines to remain and cap those that are not required in accordance with instructions of the Utility Companies, and all other authorities having jurisdiction. 2. Clearing the site within the clearing limits, including removal of grass, brush, shrubs, trees, loose debris, and other encumbrances except for trees to remain. 3. Boxing and protecting all areas to be preserved. 4. Removing all topsoil from designated areas and stockpiling on site where directed by the Engineer for future use. 5. Disposing from the site all debris resulting from work under this Section. 2. Related Work: Related Contract Work is described in the following sections of the Specifications: Work Section Excavation 02222 Embankment 02223 Erosion and Sedimentation Control 02270 B. Materials Not Used. C. Submittals Not Used. Site Preparation: Site Preparation includes clearing, grubbing, and/or stripping operations. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Site Preparation Page 02110-2 D. Construction 1. Clearing of the Site: a. Clearing limits, as shown on the Contract Drawings, shall be established by the Contractor’s Surveyor. Once established, the clearing limits shall be inspected and approved by the Engineer prior to clearing the affected areas. b. Install required erosion and sedimentation control measures prior to performing clearing and grubbing activities. c. Before the start of excavation and grading operations, the areas within the clearing limits shown on the Contract Drawings shall be cleared and grubbed. d. Clearing shall consist of cutting, removal, and satisfactory disposal of all trees, fallen timber, brush, bushes, rubbish, fencing, and other perishable and objectionable material. Should it become necessary to remove a tree, bush, brush, or other plants outside the clearing limits, the Contractor shall do so only after permission has been granted by the Engineer. e. Where necessary, excavation resulting from the removal of trees, roots, and the like shall be filled with suitable material, as approved by the Engineer, and thoroughly compacted per the requirements contained in Section 02223, Embankment, of these Specifications. e. In temporary construction easement locations, only those trees and shrubs shall be removed which are in actual interference with excavation or grading work under this Contract, and removal shall be subject to approval by the Engineer. However, the Engineer reserves the right to order additional trees and shrubs removed at no additional cost to the Owner, if such, in their opinion, they are too close to the work to be maintained or have become damaged due to the Contractor's operations. 2. Stripping and Stockpiling Existing Topsoil: a. Existing topsoil and sod on the site within areas designated on the Contract Drawings shall be stripped to whatever depth it may occur, and stored in locations directed by the Engineer. b. The topsoil shall be free of stones, roots, brush, rubbish, or other unsuitable materials before stockpiling. c. Care shall be taken not to contaminate the stockpiled topsoil with any unsuitable materials. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Site Preparation Page 02110-3 3. Grubbing: a. Grubbing shall consist of the removal and disposal of all stumps, roots, logs, sticks, and other perishable materials to a depth of at least 6 inches below ground surfaces. b. Large stumps located in areas to be excavated may be removed during grading operations, subject to the approval of the Engineer. 4. Disposal of Cleared and Grubbed Material: Open burning of clearing debris will be allowed on this project with necessary permits and prior approval from the local Fire Department. Any material other than plant growth shall not be burned. Otherwise, all trees, stumps, roots, bushes, etc. shall be removed from the site and disposed of by the Contractor. Alternatively, the Contractor may grind woody materials into wood mulch and either remove from the site or stockpile on-site in the location(s) approved by the Owner. END OF SECTION DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 This page intentionally left blank. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Excavation Page 02222-1 SECTION 02222 EXCAVATION A. Description 1. General: The Contractor shall furnish all labor, material, and equipment required to complete Excavation of the project area in accordance with the Contract Drawings and these Specifications, except as noted below: a. Clearing and grubbing and removal of topsoil is addressed in Section 02110, Site Preparation, of these Specifications. 2. Related Work: Related Contract Work is described in the following sections of the Specifications: Work Section Site Preparation 02110 Embankment 02223 Erosion and Sedimentation Control 02270 3. Definitions: a. Excavation: shall consist of the removal and satisfactory disposal and/or stockpiling of all materials (borrow and/or unsuitable materials included) located with the limits of construction including widening cuts and shaping of slopes necessary for the preparation of roadbeds, slope areas, cutting of any ditches, channels, waterways, entrances, and other work incidental thereto. b. Borrow: shall consist of approved on-site material required for the construction of embankments/fills or for other portions of the work. c. Select Borrow (Where Applicable): shall consist of approved off-site material required for the construction of embankments/fills, roadway subgrade, backfilling, or for other portions of the work as shown on Contract Drawings or in these Specifications. The Contractor shall make their own arrangements for obtaining select borrow and pay all costs involved. d. Unsuitable Material: is any in-place or excavated material which contains undesirable materials or is in a state which is not appropriate for the intended use or support of planned structures, embankment, or excavation. This may Excavation: Excavation includes excavating, sealing, hauling, scraping, undercutting, removal of accumulated surface water or ground water, stockpiling, and all necessary and incidental items as required for bringing the site to the specified lines and grades. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Excavation Page 02222-2 include but not be limited to organic material, waste/refuse, soft, or wet material not meeting required specifications, etc. e. Unsuitable Material Overexcavation: shall consist of the removal and satisfactory disposal of all unsuitable material located within the limits of construction and below subgrade elevations shown or indicated on the Contract Drawings. Where excavation to the subgrade elevations results in a subgrade or slopes of unsuitable material, the Contractor shall overexcavate such material to below the grades shown or indicated on the Contract Drawings or as otherwise directed by the Engineer. B. Materials Excavation shall include the removal of all soil, weathered rock, boulders, conduits, pipe, unsuitable material, and all other obstacles encountered and shown or indicated on the Contract Drawings and/or specified herein. C. Submittals Not Used. D. Construction 1. The Contractor shall conduct Excavation activities in such a manner that erosion of disturbed areas and off site sedimentation is absolutely minimized as outlined in Section 02270, Erosion and Sedimentation Control, of these Specifications. 2. The Contractor shall excavate to the lines and grades shown on the Contract Drawings. The Contractor will perform all surveys necessary to establish and verify lines and grades for all Excavation, including pipe excavations, soil overexcavation, and anchor trenches. 3. Stockpiling: The Contractor shall stockpile materials as needed in appropriate stockpiles as approved by the Engineer. Stockpiles shall be properly sloped and the surfaces sealed by the Contractor at the end of each working day, or during the day in the event of heavy rain, to the satisfaction of the Engineer. 4. The Contractor shall protect all existing facilities and structures including, but not limited to, existing utilities, monitoring wells, signs, grade stakes, etc. during the grading and stockpiling operations. 5. All excavations shall be made in the dry and in such a manner and to such widths as will give ample room for properly constructing and inspecting the structures and/or piping they are to contain and for such sheeting, timbering, pumping, and drainage as may be required. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Excavation Page 02222-3 6. The Contractor shall be responsible for the control of surface and subsurface water when necessary. Except for certain erosion and sedimentation control measures and other areas designated to impound water, all areas shall be graded to drain. 7. Excavation slopes shall be flat enough to avoid sloughs and slides that will cause disturbance of the subgrade or damage of adjacent areas. Slides and overbreaks which occur due to negligence, carelessness, or improper construction techniques on the part of the Contractor shall be removed and disposed of by the Contractor as directed by the Engineer at no additional cost to the Owner. 8. The intersection of slopes with natural ground surfaces, including the beginning and ending of cut slopes, shall be uniformly rounded. All protruding roots and other vegetation shall be removed from slopes. 9. The bottom of all excavations for structures and pipes shall be examined by the Engineer for bearing value and the presence of unsuitable material. If, in the opinion of the Engineer, additional Excavation is required due to the low bearing value of the subgrade material, or if the in-place materials are soft, yielding, pumping and wet, the Contractor shall remove such material to the required width and depth and replace it with thoroughly compacted structural fill, or material directed by the Engineer. No payment will be made for subgrade disturbance caused by inadequate Dewatering or improper construction methods. 10. Any areas excavated below design subgrade elevations by the Contractor, unless directed by the Engineer, shall be brought back to design elevations at no cost to the Owner. The Contractor shall place and compact such material in accordance with Section 02223, Embankment, of these Specifications. 11. The Contractor shall dispose of excess or unsuitable excavation materials on-site at location(s) approved by the Owner. 12. The Contractor shall properly level-off bottoms of all excavations. Proof-rolling shall be conducted with appropriate equipment. 13. Upon reaching subgrade elevations shown in excavation areas, the Contractor shall scarify subgrade soils to a minimum depth of 6" and obtain the Engineer’s approval of quality. If unsuitable materials are encountered at the subgrade elevation, perform additional excavations as approved by the Engineer to remove unsuitable materials. 14. Overexcavation and Backfill: a. Where subgrade materials are determined to be unsuitable, such materials shall be removed by the Contractor to the lengths, widths, and depths approved by the Engineer in advance and backfilled with compacted Embankment in accordance with Section 02223, Embankment, of these Specifications. b. No additional payment will be made for such overexcavation and backfill 1 foot or less than the finished subgrade (or pre-existing grades where pre-existing grades are lower than finished subgrade) as this is considered superficial. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Excavation Page 02222-4 c. Where overexcavation of unsuitable material is greater than 1 foot beneath the finished subgrade (or pre-existing grades where pre-existing grades are lower than finished subgrade), payment shall be made on a unit price basis for overexcavation and backfill and the measured quantity shall include the entire excavation quantity below the finished subgrade (or pre-existing grades where pre-existing grades are lower than finished subgrade) elevations. The unit price for overexcavation and backfill shall include disposal of unsuitable materials. 15. All cuts shall be brought to the grade and cross section shown or indicated on the Contract Drawings, or established by the Engineer, prior to final inspection. 16. The Contractor shall protect finished lines and grades of completed excavation against excessive erosion, damage from trafficking, or other causes and shall repair any damage at no additional cost to the Owner. 17. Trench Excavation: a. All pipe Excavation and trenching shall be done in strict accordance with these Specifications, all applicable parts of the OSHA Regulations, 29 CFR 1926, Subpart P, and other applicable regulations. In the event of any conflicts in this information, safe working conditions as established by the appropriate OSHA guidelines shall govern. b. The minimum trench widths shall be as indicated on the Contract Drawings. Enlargements of the trench shall be made as needed to give ample space for operations at pipe joints. The width of the trench shall be limited to the maximum dimensions shown on the Contract Drawings, except where a wider trench is needed for the installation of and work within sheeting and bracing. c. Except where otherwise specified, excavation slopes shall be flat enough to avoid slides which will cause disturbance of the subgrade, damage to adjacent areas, or endanger the lives or safety of persons in the vicinity. d. Hand excavation shall be employed wherever, in the opinion of the Engineer, it is necessary for the protection of existing utilities, poles, trees, pavements, obstructions, or structures. e. No greater length of trench in any location shall be left open, in advance of pipe laying, than shall be authorized or directed by the Engineer and, in general, such length shall be limited to approximately one hundred (100) feet. f. Pipe Bedding: All pipe bedding shall be as shown on the Contract Drawings, unless otherwise specified herein, or shall be approved by the Engineer. 18. Sheeting and Bracing: a. The Contractor shall furnish, place, and maintain such sheeting and bracing which may be required to support sides of Excavation or to protect pipes and structures from possible damage and to provide safe working conditions in DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Excavation Page 02222-5 accordance with current OSHA requirements. If the Engineer is of the opinion that at any point sufficient or proper supports have not been provided, they may order additional supports put in at the sole expense of the Contractor. The Contractor shall be responsible for the adequacy of all sheeting and bracing used and for all damage resulting from sheeting and bracing failure or from placing, maintaining, and removing it. b. The Contractor shall exercise caution in the installation and removal of sheeting to insure that excessive or unusual loadings are not transmitted to any new or existing structure. The Contractor shall promptly repair at their expense any and all damage that can be reasonably attributed to sheeting installation or removal. c. All sheeting and bracing shall be removed upon completion of the work. 19. If grading operations are suspended for any reason whatsoever, partially completed cut and fill slopes shall be brought to the required slope and the work of seeding and mulching or other required erosion and sedimentation control operations shall be performed at the Contractor’s sole expense. END OF SECTION DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 This page intentionally left blank. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Embankment Page 02223-1 SECTION 02223 EMBANKMENT A. Description 1. General: The Contractor shall furnish all labor, material, and equipment to complete Embankment including borrowing, hauling, screening, discing, drying, compaction, control of surface and subsurface water, final grading, sealing, and all necessary and incidental items as detailed or required to complete the Embankment, all in accordance with the Contract Drawings and these Specifications. 2. Related Work: Related Contract Work is described in the following sections of the Specifications: Work Section Excavation 02222 Erosion and Sedimentation Control 02270 3. Reference Standards: The latest revision of the following standards of the American Society of Testing and Materials (ASTM) are hereby made a part of these Specifications. ASTM D 698 Test Method for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft3). ASTM D 1556 Standard Test Method for Density and Unit Weight of Soil in Place by the Sand-Cone Method. ASTM D 2167 Standard Test Method for Density and Unit Weight of Soil in Place by the Rubber Balloon Method. ASTM D 2216 Standard Test Method for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass. ASTM D 2487 Standard Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System). ASTM D 2488 Standard Practice for Description and Identification of Soils (Visual-Manual Procedure). Embankment: Embankment is the on-site compacted fill that provides the foundation and the berms for the containment area, the subgrade for some access roadways and structures, and backfill around structures and piping. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Embankment Page 02223-2 ASTM D 2937 Standard Test Method for Density of Soil in Place by the Drive Cylinder Method. ASTM D 4643 Standard Test Method for Determination of Water (Moisture) Content of Soil by the Microwave Oven Method. ASTM D 4959 Standard Test Method for Determination of Water (Moisture) Content of Soil by Direct Heating Method. ASTM D 6938 Standard Test Methods for In-Place Density and Water Content of Soil and Soil-Aggregate in Place by Nuclear Methods (Shallow Depth). 4. Quality Assurance: Quality Assurance during placement of Embankment will be provided by the Owner. 5. Definitions: a Embankment: Shall include construction of all site earthwork including roadways, subgrade, perimeter berm embankments, including preparation of the areas upon which materials are to be placed. Embankment may also be referred to as structural and/or controlled fill. All Embankment materials may be either (off-site) Select Borrow or (on-site) Borrow unless otherwise noted on Contract Drawings or specified by the Engineer. b. Prepared Subgrade: The ground surface after clearing, grubbing, stripping, excavation, scarification, and/or compaction, and/or proof rolling to the satisfaction of the Engineer. c. Well-Graded: A mixture of particle sizes that has no specific concentration or lack thereof of one or more sizes. Well-graded does not define any numerical value that must be placed on the coefficient of uniformity, coefficient of curvature, or other specific grain size distribution parameters. Well-graded is used to define a material type that, when compacted, produces a strong and relatively incompressible soil mass free from detrimental voids. d. Unclassified Fill: The nature of materials to be used is not identified or described herein but must be approved by the Engineer prior to use. B. Materials 1. Embankment materials shall consist of clean well-graded natural soil classified as SP, SW, SM, SC, ML, or CL (ASTM D 2487) containing no topsoil or other deleterious material. Other material classifications may be approved by the Engineer. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Embankment Page 02223-3 2. Stones or rock fragments shall not exceed one half the maximum lift thickness as compacted in any dimension. Isolated rocks shall be a maximum of 24-inches in any dimension. C. Submittals Not Used. D. Construction 1. The Contractor shall conduct Embankment activities in such a manner that erosion of disturbed areas and off-site sedimentation is absolutely minimized as outlined in Section 02270, Erosion and Sedimentation Control, of these Specifications. 2. All placement and compaction of Embankment shall be performed only when the Engineer is informed by the Contractor of intent to perform such work. 3. Embankment shall be placed and compacted to the lines and grades shown on the Contract Drawings. Placement of Embankment outside the construction limits shall occur only as directed and approved by the Engineer. The Contractor will perform all surveys necessary to establish and verify lines and grades for all Embankment. 4. The Contractor shall protect all existing facilities including, but not limited to, utilities and monitoring wells. 5. Subgrade Preparation: a. The Engineer shall inspect the exposed subgrade prior to placement of Embankment to assure that all rocks, topsoil, vegetation, roots, debris, or other deleterious materials have been removed. b. Prior to placement of Embankment, the exposed subgrade shall be proofrolled using a static smooth-drum roller, loaded tandem axle dump truck, or other suitable equipment in the presence of the Engineer. Any soft or unsuitable materials revealed before or during the in-place compaction shall be removed as directed by the Engineer and replaced with suitable Embankment. 6. Surfaces on which Embankment is to be placed, shall be scarified or stepped in a manner which will permit bonding of the Embankment with the existing surface. 7. The Contractor shall be responsible for preparing the materials for the Embankment, including but not limited to, in-place drying or wetting of the soil necessary to achieve the compaction criteria of these Specifications. 8. The Contractor shall be responsible for the control of surface and subsurface water when necessary. Except for certain erosion and sedimentation control measures and other areas designated to impound water, all areas shall be graded to drain. 9. Embankment materials shall be placed in a manner permitting drainage and in continuous, approximately horizontal layers. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Embankment Page 02223-4 10. Compaction Requirements: a. The Contractor shall compact Embankment in accordance with the requirements shown in Table 1 of this section. If Embankment does not meet the specified requirements, the Contractor shall rework the material, as may be necessary and continue compaction to achieve these requirements, or remove and replace the material to achieve the specified requirements, at Contractor's expense. b. Each lift shall be compacted prior to placement of succeeding lifts. In confined areas, mechanical equipment, suitable for small areas and capable of achieving the density requirements, shall be required. c. Lift compaction shall be performed with an appropriately heavy, properly ballasted, penetrating-foot or smooth-drum vibratory compactor depending on soil type. Compaction equipment shall be subject to approval by the Engineer. 11. Embankment that becomes excessively eroded, soft, or otherwise unsuitable shall be removed or repaired by the Contractor as directed by the Engineer, at no cost to the Owner. 12. The exposed surface of Embankment shall be rolled with a smooth-drum roller at the end of each work day to protect from adverse weather conditions. 13. Where Embankment is to be placed and compacted on slopes that are steeper than 3H:1V, the subgrade shall be benched to a minimum depth of 6 inches and the Embankment shall be placed in horizontal lifts. 14. Backfilling for Structures and Piping: a. All structures, including manholes and pipes shall be backfilled with Embankment as shown in the Contract Drawings and as described in these Specifications. b. Where sheeting is used, the Contractor shall take all reasonable measures to prevent loss of support beneath and adjacent to pipes and existing structures when sheeting is removed. If significant volumes of soil cannot be prevented from clinging to the extracted sheets, the voids shall be continuously backfilled as rapidly as possible. The Contractor shall thereafter limit the depth below subgrade that sheeting will be driven in similar soil conditions or employ other appropriate means to prevent loss of support. c. When backfilling around structures, do not backfill until concrete has sufficiently cured (as determined by the Engineer) and is properly supported. Place backfill in a manner to avoid displacement or damage of structures. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Embankment Page 02223-5 Table 1: Required Embankment Properties Item Required % Standard Proctor (ASTM D698)2 Required Moisture Content3 Maximum Lift Thickness (Compacted) (inches) Embankment Beneath Structures and Roads1 100 +/- 2% of Optimum (std. Proctor) 8 Embankment 95 As Required for Compaction 8 Backfill Around Structures 95 8 Backfill in Pipe Trenches 95 6 Unclassified Fill N/A N/A N/A Notes: 1. Embankment beneath structures shall be considered to include a zone 10 feet out from the foundation of the structure extending down to the natural ground on a 45° slope. Embankment beneath roads shall be considered to include all embankment placed within 3 vertical feet of the final wearing surface and shall also include shoulders. 2. Determine field density using ASTM D 6938, ASTM D 1556, ASTM D 2167, or ASTM D 2937. 3. Determine field moisture content using ASTM D 6938, ASTM D 2216, ASTM D 4643, or ASTM D 4959. 4. The Engineer may allow exceptions to the above criteria for areas outside of the containment area which are not subject to significant long-term loads. END OF SECTION DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 This page intentionally left blank. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Geotextiles Page 02240-1 SECTION 02240 GEOTEXTILES A. Description 1. General: The Contractor shall furnish all labor, material, and equipment to complete installation of Geotextiles including all necessary and incidental items as detailed or required for the Contractor to complete the installation in accordance with the Contract Drawings and these Specifications, except as noted below: a. Geotextiles used as a Silt Fence is covered under Section 02270, Erosion and Sedimentation Control, of these Specifications. 2. Related Work: Related Contract Work is described in the following sections of the Specifications: Work Section Erosion and Sedimentation Control 02270 3. Reference Standards: The latest revision of the following standards of the American Society of Testing and Materials (ASTM) and the American Association of State Highway and Transportation Officials (AASHTO) are hereby made a part of these specifications. ASTM D 4355 Standard Test Method for Deterioration of Geotextiles by Exposure to Light, Moisture, and Heat in a Xenon-Arc Type Apparatus. ASTM D 4491 Standard Test Methods for Water Permeability of Geotextiles by Permittivity. ASTM D 4533 Standard Test Method for Trapezoid Tearing Strength of Geotextiles. ASTM D 4632 Standard Test Method for Grab Breaking Load and Elongation of Geotextiles. ASTM D 4751 Standard Test Method for Determining Apparent Opening Size of a Geotextile. Geotextiles: For the proposed construction, a Type GT-S (Separator/Filter) Geotextile is specified. The Type GT-S Geotextile will be placed in the laydown yard, between soil subgrade and aggregate in access roads and in some erosion control and drainage applications. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Geotextiles Page 02240-2 ASTM D 5261 Standard Test Method for Measuring Mass per Unit Area of Geotextiles. ASTM D 6241 Standard Test Method for the Static Puncture Strength of Geotextiles and Geotextile Related Products Using a 50 mm Probe. AASHTO M 288 Standard Specification for Geotextiles. 4. Quality Assurance: Quality Assurance during installation of Geotextiles will be provided by the Owner. B. Materials 1. General: The materials supplied under these Specifications shall consist of new, first-quality products designed and manufactured specifically for the purpose of this work, which shall have been satisfactorily demonstrated, by prior use, to be suitable and durable for such purposes. Labels on each roll of Geotextile shall identify the length, width, lot and roll numbers, and name of Manufacturer. 2. The Type GT-S Geotextile shall be a nonwoven spunbonded or nonwoven needlepunched synthetic fabric consisting of polyester or polypropylene manufactured in a manner approved by the Engineer. Woven fabrics may be used in certain applications if approved in advance by the Engineer. 3. All Geotextiles shall conform to the properties listed in Table 1 of this section. C. Submittals Prior to the installation of Geotextiles, the Contractor shall submit the following to the CQA Engineer: 1. Mill Certificate and Sample: Prior to shipping to the site, the Contractor shall submit a mill certificate or affidavit signed by a legally authorized official of the Manufacturer for each type of Geotextile attesting that the Geotextiles meet the physical and manufacturing requirements stated in these Specifications including needle detection and removal procedures (as applicable). The Contractor shall also submit a sample of each Geotextile to be used. The samples shall be labeled with the product name and be accompanied by the Manufacturer's specifications. 2. Shipping, Handling, and Storage Instructions: The Manufacturer's plan for shipping, handling, and storage shall be submitted for review. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Geotextiles Page 02240-3 3. Seaming Procedures: Submit proposed seaming procedures including proposed method and equipment. 4. Quality Control Certificates: For Geotextiles delivered to the site, quality control certificates, signed by the Manufacturer's quality assurance manager shall be provided which represent every roll of each type of Geotextile supplied. Each certificate shall have the roll identification number(s), test methods, frequency, and test results. At a minimum, the test results and frequency of testing shall be as shown in Table 2 of this section. 5. Furnish copies of the delivery tickets or other approved receipts as evidence for materials received that will be incorporated into the construction. D. Construction 1. Shipping, Handling, and Storage: All Geotextiles shall be shipped, handled, and stored in strict accordance with the Manufacturer's recommendations. 2. Failing CQA Material Control Tests: Geotextiles that are rejected upon testing shall be removed from the project site and replaced at Contractor's cost. Sampling and CQA testing of Geotextiles supplied as replacement for rejected material shall be performed by the Engineer at Contractor's cost. 3. Installation: a. The surface receiving the Geotextiles shall be prepared to a relatively smooth condition, free of obstructions, standing water, excessive depressions, debris, and very soft, excessively wet, and/or loose pockets of soil. This surface shall be approved by the Engineer prior to Geotextile placement. b. Geotextiles shall be placed to the lines and grades shown on the Contract Drawings. At the time of installation, Geotextiles shall be rejected by the Engineer if they have defects, rips, holes, flaws, evidence of deterioration, or other damage. c. The Geotextiles shall be placed smooth and free of excessive wrinkles. d. On slopes, Geotextiles shall be anchored at the top and unrolled down the slope. In the presence of wind, all Geotextiles shall be weighted with sandbags or other material as appropriate. Geotextiles uplifted by wind may be reused upon approval by the Engineer. 4. Seams: a. Seams to be heat bonded shall be bonded using hot plate, hot knife, ultrasonic, or other approved devices. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Geotextiles Page 02240-4 5. Repair Procedures: a. Any Geotextile that is torn, punctured, or otherwise damaged shall be repaired or replaced, as directed by the Engineer, by the Contractor at no additional cost to the Owner. The repair shall consist of a patch of the same type of Geotextile placed over the failed areas and shall overlap the existing Geotextile a minimum of 18 inches from any point of the rupture. Patches shall be spot sewn or heat bonded so as not to shift during cover placement. b. Slopes Flatter Than 6H:1V: Damaged areas of a size exceeding 10 percent of the roll width shall be removed and replaced across the entire roll width with new material. Damaged areas of a size less than 10 percent of the roll width may be patched. c. Slopes of 6H:1V or Steeper: Geotextile panels which require repair shall be removed and replaced with new material. Replacement material shall be sewn as previously described in this specification. 6. Cover Placement: a. Except when designed to remain exposed, Geotextiles shall be covered in a timely manner to limit potential UV damage. Unless otherwise approved by the Engineer, covering shall occur within 30 days of installation. Extension of this time may be considered by the Engineer based on weather conditions (i.e. prolonged cloud cover during 30 day period) or technical information provided by the Manufacturer that would justify an extension. (1) The Engineer may conduct sampling and testing of any Geotextiles exposed for a period longer than allowed to verify the material properties. The cost associated with this testing and the subsequent repair(s) shall be borne solely by the Contractor regardless of the test results. In no case will the maximum length of exposure be greater than 60 days without verification of material properties. b. Placement of cover over Geotextiles shall be performed in a manner as to ensure that the Geotextiles or underlying materials are not damaged. Cover material shall be placed such that excess tensile stress is not mobilized in the Geotextile. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Geotextiles Page 02240-5 Table 1: Required Geotextile Properties Property Test Method Units Value1 Type GT-S Geotextile Construction (NW = Nonwoven) (W = Woven) ----- ----- NW2 or W3 Mass per Unit Area (Unit Weight) ASTM D 5261 oz/yd2 N/A UV Resistance (500 hrs) ASTM D 4355 % 70 Strength Class4 AASHTO M 288 Class 2 Tensile Properties: ASTM D 4632 Grab Strength lbs 160 (NW) 250 (W) Grab Elongation % > 50 (NW) < 50 (W) Puncture Resistance ASTM D 6241 lbs 410 (NW) 950 (W) Trapezoidal Tear Strength ASTM D 4533 lbs 55 (NW) 90 (W) Apparent Opening Size (AOS) ASTM D 4751 U.S. Sieve 70+ Permittivity ASTM D 4491 sec-1 1.0 Notes: 1. Minimum Average Roll Value (MARV). 2. Nonwoven geotextiles that have been heat calendered are not acceptable, unless approved by the Engineer in advance. 3. Woven geotextiles shall be approved in advance by the Engineer. Woven geotextiles formed exclusively with slit film fibers are not acceptable. 4. AASHTO M 288 criteria include the above listed requirements for: Tensile Properties, Puncture Resistance, Trapezoidal Tear Strength, and Burst Strength. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Geotextiles Page 02240-6 Table 2: Required Manufacturer Quality Control Tests Property Test Method Minimum Test Frequency Mass per Unit Area (Unit Weight) ASTM D 5261 200,000 ft2 Ultraviolet Resistance (500 hrs) ASTM D 4355 Periodic Tensile Properties ASTM D 4632 200,000 ft2 Apparent Opening Size (AOS) ASTM D 4751 Periodic Permittivity ASTM D 4491 Periodic Puncture Resistance ASTM D 6241 200,000 ft2 Trapezoidal Tear Strength ASTM D 4533 200,000 ft2 END OF SECTION DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Erosion and Sedimentation Control Page 02270-1 SECTION 02270 EROSION AND SEDIMENTATION CONTROL A. Description 1. General: The Contractor shall furnish all labor, material, and equipment to complete installation of and maintain Erosion and Sedimentation Control measures and related work in accordance with the Contract Drawings and these Specifications. All Erosion and Sedimentation Control work shall be in accordance with the latest edition of the North Carolina Erosion and Sediment Control Planning and Design Manual as well as applicable regulations. 2. Related Work: Related Contract Work is described in the following sections of the Specifications: Work Section Geotextiles 02240 Rip Rap 02271 Rolled Erosion Control Products 02275 Precast Concrete Structures 02608 Stormwater Systems 02720 Revegetation 02930 3. Reference Standards: The latest revision of the following standards of the American Society of Testing and Materials (ASTM) are hereby made a part of these specifications. ASTM D 3786 Test Method for Hydraulic Bursting Strength of Knitted Goods and Nonwoven Fabrics: Diaphragm Bursting Strength Tester Method. ASTM D 4355 Standard Test Method for Deterioration of Geotextiles from Exposure to Ultraviolet Light and Water (Xenon-Arc Type Apparatus). ASTM D 4491 Standard Test Methods for Water Permeability of Geotextiles by Permittivity. Erosion and Sedimentation Control: Erosion and Sedimentation Control is a system of construction and engineered measures (devices, structures, practices, etc.) which act to minimize surface water induced erosion of disturbed areas and the resulting off-site sedimentation. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Erosion and Sedimentation Control Page 02270-2 ASTM D 4533 Standard Test Method for Trapezoid Tearing Strength of Geotextiles. ASTM D 4632 Standard Test Method for Grab Breaking Load and Elongation of Geotextiles. ASTM D 4751 Standard Test Method for Determining Apparent Opening Size of a Geotextile. ASTM D 4833 Standard Test Method for Index Puncture Resistance of Geotextiles, Geomembranes, and Related Products. B. Materials 1. Permanent Sediment or Detention Basins: Permanent sediment or detention basins shall be constructed as shown on the Contract Drawings. 2. Permanent Drainage Channels, Diversions, Swales, and Ditches: Permanent drainage channels, diversions, swales, and ditches shall be constructed as shown on the Contract Drawings. 3. Silt Fence: Silt fences shall be constructed as shown on the Contract Drawings and as needed, based on the Contractor’s discretion and Engineer’s approval. The silt fence is a permeable barrier erected within and downgradient of small disturbed areas to capture sediment from sheet flow. It is made of filter fabric buried at the bottom, stretched, and supported by posts and wire mesh backing. Silt fence shall conform to the following properties: a. Posts: Posts shall be 1.33 lb/linear foot steel (preferred) or wood with a minimum length of 5 feet. Steel posts shall be “U” or “T”-type. Wood posts shall have a minimum diameter of 4-inches. b. Filter Fabric: Filter fabric shall be a woven geotextile made specifically for sediment control. Filter fabric shall conform to the properties listed in Table 1 of this section. 5. Geotextiles: Geotextiles shall conform to the requirements of Section 02240, Geotextiles, of these Specifications. 6. Rip Rap: Rip Rap shall conform to the requirements of Section 02271, Rip Rap, of these Specifications. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Erosion and Sedimentation Control Page 02270-3 7. Rolled Erosion Control Products (RECPs): Rolled Erosion Control Products (RECPs) shall conform to the requirements of Section 02275, Rolled Erosion Control Products, of these Specifications. 8. Other Work: In addition to the Erosion and Sedimentation Control measures shown on the Contract Drawings, the Contractor shall provide adequate means to prevent any sediment from entering any storm drains, drop inlets, ditches, streams, or bodies of water downstream of any area disturbed by construction. Excavation materials shall be placed upstream of any trench or other excavation to prevent sedimentation of off-site areas. In areas where a natural buffer area exists between the work area and the closest stream or water course, this area shall not be disturbed. All paved areas shall be scraped and swept as necessary to prevent the accumulation of dirt and debris. Work associated with this provision shall be considered incidental to the project and no separate payment will be made. 9. Temporary and Permanent Soil Stabilization: Unless State/local requirements are stricter, the Contractor shall provide temporary or permanent soil stabilization on denuded areas within 7 days after final grade is reached on any portion of the site. The Contractor shall provide temporary soil stabilization within 7 days to denuded areas that may not be at final grade but will remain dormant for longer than 14 days. The Contractor shall provide permanent stabilization to all remaining denuded areas and/or areas with temporary stabilization upon completion of construction. C. Submittals The Contractor shall submit the following to the Engineer: 1. Submit a certification and summary of all required test results, prior to installation, that all Erosion and Sedimentation Control materials manufactured for the project have been produced in accordance with these Specifications. 2. Furnish copies of the delivery tickets or other approved receipts as evidence for materials received that will be incorporated into construction. D. Construction 1. Establishment of Erosion and Sedimentation Control Measures: a. All Erosion and Sedimentation Control measures will be constructed according to the Contract Drawings and these Specifications. b. Due to the nature of the work required by this Contract, it is anticipated that the location and nature of the Erosion and Sedimentation Control measures may need to be adjusted to reflect the current phase of construction. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Erosion and Sedimentation Control Page 02270-4 c. Erosion and Sedimentation Control measures shall be established prior to the work in a given area. Where such practice is not feasible, the Erosion and Sedimentation Control measure(s) shall be established immediately following completion of the clearing operation. d. The construction schedule adopted by the Contractor will impact the placement and need for specific measures required for the control of erosion. The Contractor shall develop and implement such additional techniques as may be required to minimize erosion and prevent or correct the discharge of sediment outside the limits of construction (unless controlled by other on-site measure(s)). e. The location and extent of Erosion and Sedimentation Control measures shall be revised at each phase of construction that results in a change in either the quantity or direction of surface runoff from construction areas. All deviations from the control provisions shown on the Contract Drawings shall have the prior approval of the Engineer. 2. Inspection and Maintenance of Erosion and Sedimentation Control Measures: a. The Contractor shall furnish the labor, material, and equipment required for the inspection and maintenance of all Erosion and Sedimentation Control measures. Maintenance shall be scheduled as required for a particular measure to maintain the removal efficiency and intent of the measure. b. All Erosion and Sedimentation Control measures shall be inspected at least once every seven calendar days and within 24 hours after any storm event of greater than 0.5 inches of rain per 24 hour period and appropriate maintenance conducted. A rain gauge shall be maintained on the site and a record of the rainfall amounts and dates shall be kept properly. c. Maintenance shall include, but not be limited to: (1) The removal and satisfactory disposal of trapped or deposited sediments from basins, traps, barriers, filters, and/or drainage features/devices; (2) Replacement of filter fabrics used for silt fences upon loss of efficiency; and (3) Replacement of any other components which are damaged or cannot serve the intended use. d. The Contractor shall accept and maintain any existing sediments that are included in existing sediment basins and traps that accept or will accept stormwater flow and or sediment accumulation from all areas within the Contractor’s limits of construction. All of these sediment basins and/or traps shall be cleaned of sediments accumulated during the performance of this project. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Erosion and Sedimentation Control Page 02270-5 e. Sediments removed from Erosion and Sedimentation Control measures shall be disposed of in locations that will not result in off-site sedimentation as approved by the Engineer. f. All Erosion and Sedimentation Control measures shall be maintained to the satisfaction of the Engineer until the site has been stabilized. 3. Graded Slopes and Fills: The angle for graded slopes and fills shall be no greater than the angle that can be retained by vegetated cover or other adequate measures. 4. Finish Grading: All disturbed areas shall be uniformly graded to the lines, grades, and elevations shown on the Contract Drawings. Except for certain erosion and sedimentation control measures and other areas designated to impound water, all areas shall be graded to drain. Finished surfaces shall be reasonably smooth, compacted, and free from irregular surface changes. Unless otherwise specified, the degree of finish shall be that ordinarily obtainable from either blade or scraper operations. Areas shall be finished to a smoothness suitable for application of topsoil. 5. Revegetation: Revegetation shall conform to the requirements of Section 02930, Revegetation, of these Specifications. 6. Cleanup: a. The Contractor shall remove from the site all debris from their work including, but not limited to, branches, paper, and rubbish in all landscape areas, and remove temporary barricades as the work proceeds. b. All areas shall be kept in a neat, orderly condition at all times. Prior to final acceptance, the Contractor shall clean up the entire landscaped area to the satisfaction of the Engineer. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Erosion and Sedimentation Control Page 02270-6 Table 1: Required Silt Fence Filter Fabric Properties Property Test Method Units Value1 Grab Tensile Strength2 ASTM D 4632 lbs 90 x 90 Grab Elongation ASTM D 4632 % 20 (Max.) Ultraviolet Resistance (500 hrs) ASTM D 4355 % 80 Apparent Opening Size (AOS) ASTM D 4751 U.S. Sieve 30+ Permittivity ASTM D 4491 sec-1 0.05 Notes: 1. Minimum Average Roll Value (MARV). 2. Values for machine and cross machine direction (MD x XD), respectively. END OF SECTION DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Rip Rap Page 02271-1 SECTION 02271 RIP RAP A. Description 1. General: The Contractor shall furnish all labor, material, and equipment to complete installation of Rip Rap for protection of earthen slopes against erosion as indicated, including all necessary and incidental items, in accordance with the Contract Drawings and these Specifications. 2. Related Work: Related Contract Work is described in the following sections of the Specifications: Work Section Geotextiles 02240 Erosion and Sedimentation Control 02270 3. Reference Standards: The latest revision of the following standards of the North Carolina Department of Transportation (NCDOT) are hereby made a part of these Specifications. NCDOT Standard Specifications for Roads and Structures. B. Materials 1. Rip Rap: Rip Rap shall be of the size indicated on the Contract Drawings and shall conform to NCDOT Section 1042, Rip Rap Materials. 2. Geotextiles: Geotextiles shall conform to the requirements outlined in Section 02240, Geotextiles, of these Specifications. C. Submittals The Contractor shall submit the following to the Engineer: 1. Submit a certification and summary of all required test results prior to installation, that all Rip Rap has been produced in accordance with these Specifications. Rip Rap: This section includes all rip rap aprons and channel protection. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Rip Rap Page 02271-2 2. Furnish copies of the delivery tickets or other approved receipts as evidence for materials received that will be incorporated into construction. D. Construction 1. Surface Preparation: a. Trim and dress all areas to conform to the Contract Drawings as indicated with tolerance of 2 inches from theoretical slope lines and grades. b. Bring areas that are below allowable minimum tolerance limit to grade by filling with compacted Embankment material similar to adjacent material. c. Geotextiles shall be placed as shown on the Contract Drawings and in accordance with Section 02240, Geotextiles, of these Specifications. d. Do not place any stone material on the prepared surface prior to inspection and approval to proceed from the Engineer. 2. Placing Rip Rap: Rip Rap shall be placed in accordance with NCDOT Section 876, Rip Rap. END OF SECTION DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Rolled Erosion Control Products Page 02275-1 SECTION 02275 ROLLED EROSION CONTROL PRODUCTS A. Description 1. General: The Contractor shall furnish all labor, material, and equipment to complete installation of all RECPs in accordance with the Contract Drawings and these Specifications. 2. Related Work: Related Contract Work is described in the following sections of the Specifications: Work Section Erosion and Sedimentation Control 02270 Revegetation 02930 3. Reference Standards: The latest revision of the following standards of the American Society of Testing and Materials (ASTM) are hereby made a part of these specifications. ASTM D 4355 Standard Test Method for Deterioration of Geotextiles from Exposure to Ultraviolet Light and Water (Xenon-Arc Type Apparatus). ASTM D 6475 Standard Test Method for Measuring Mass per Unit Area of Erosion Control Blankets. ASTM D 6524 Standard Test Method for Measuring the Resiliency of Turf Reinforcement Mats. ASTM D 6525 Standard Test Method for Measuring Nominal Thickness of Permanent Erosion Control Products. ASTM D 6566 Standard Test Method for Measuring Mass per Unit Area of Turf Reinforcement Mats. ASTM D 6818 Standard Test Method for Ultimate Tensile Properties of Turf Reinforcement Mats. Rolled Erosion Control Products: Rolled Erosion Control Products (RECPs) include erosion control blankets (ECB) placed in channels and on slopes. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Rolled Erosion Control Products Page 02275-2 B. Materials 1. General: The materials supplied under these Specifications shall consist of new, first-quality products designed and manufactured specifically for the purpose of this work, which shall have been satisfactorily demonstrated, by prior use, to be suitable and durable for such purposes. Labels on each RECP shall identify the length, width, product name, and name of Manufacturer. 2. Erosion Control Blanket (ECB) (Single Net): ECB (single net) shall consist of a machine-produced mat of straw or wood excelsior fiber covered on the top side with a photodegradable extruded plastic or woven biodegradable netting and sewn together with degradable thread. ECB (single net) shall also conform to the properties listed in Table 1 of this section. ECB (single net) shall be EroNet S75, as manufactured by North American Green, CURLEX I, as manufactured by American Excelsior Company, LANDLOK S1, as manufactured by Propex GeoSolutions, or approved equal. Flexterra Flexible Growth Media (FGM), as manufactured by Profile Products, applied at a minimum rate of 3,500 lbs/acre (or equal product/application rate) is an acceptable substitute for ECB to be placed on 2H:1V slopes (a minimum rate of 3,000 lbs/acre shall be used on 3H:1V slopes). 3. Erosion Control Blanket (ECB) (Double Net): ECB (double net) shall consist of a machine-produced mat of straw or wood excelsior fiber covered on the top and bottom sides with photodegradable extruded plastic or woven biodegradable nettings and sewn together with degradable thread. ECB (double net) shall also conform to the properties listed in Table 1 of this section. ECB (double net) shall be EroNet S150, as manufactured by North American Green, CURLEX II, as manufactured by American Excelsior Company, LANDLOK S2, as manufactured by Propex GeoSolutions, or approved equal. Flexterra Flexible Growth Media (FGM), as manufactured by Profile Products, applied at a minimum rate of 3,500 lbs/acre (or equal product/application rate) is an acceptable substitute for ECB to be placed on 2H:1V slopes (a minimum rate of 3,000 lbs/acre shall be used on 3H:1V slopes). 4. Anchors: Anchors for RECPs shall consist of machine made staples of No. 8 gauge new steel wire formed into a “U” shape. The size when formed shall be not less that 8 inches in length with a throat of not less than 1 inch in width. Longer anchors may be required for loose soils. Other anchors, such as metal pins or plastic pegs, may also be used if approved in advance by the Engineer. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Rolled Erosion Control Products Page 02275-3 C. Submittals The Contractor shall submit the following to the Engineer: 1. Mill Certificate and Sample: Prior to shipping to the site, the Contractor shall submit a mill certificate or affidavit signed by a legally authorized official of the Manufacturer for each RECP attesting that each RECP meets the physical and manufacturing requirements stated in these Specifications. The Contractor shall also submit a sample of each RECP to be used. The sample shall be labeled with the product name and be accompanied by the Manufacturer's specifications. 2. Installation Guidelines/Instructions: The Manufacturer's guidelines/instructions for installation shall be submitted for review. 3. Furnish copies of delivery tickets or other approved receipts as evidence for materials received that will be incorporated into the construction. D. Construction 1. Shipping, Handling, and Storage: All RECPs shall be shipped, handled, and stored in strict accordance with the Manufacturer's recommendations. 2. Installation - General: a. Placing of RECPs shall be done immediately following seeding. Seeding shall be performed in accordance with Section 02930, Revegetation, of these Specifications. b. RECPs shall be placed to the lines and grades shown on the Contract Drawings. The earth surface shall be smooth and free from stones, clods, or debris which will prevent the contact of the RECP with the soil. Care shall be taken to preserve the required line, grade, and cross section of the area. c. RECPs shall be unrolled in the direction of the flow of water and shall be applied without stretching so that it will lie smoothly but loosely on the soil surface. d. At the time of installation, RECPs shall be rejected, if they have defects, rips, holes, flaws, evidence of deterioration, or other damage. e. The Engineer may require adjustments in the installation requirements to fit individual conditions. 3. Installation - Channels: RECPs installed in channels shall be unrolled parallel to the direction of water flow. The first roll shall be centered longitudinally in the channel and anchored with staples. Subsequent rolls shall be installed outward to the edges of the channel and be lapped to allow installation of a common row of anchors. RECP ends shall be overlapped with the DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Rolled Erosion Control Products Page 02275-4 upstream ends on top (“shingled”). Refer to the Contract Drawings and/or the Manufacturer’s installation guidelines/instructions for installation details. 4. Installation - Slopes: RECPs installed on slopes shall be oriented in vertical strips and anchored. Subsequent rolls shall be installed outward to the edge(s) of the original roll and be lapped to allow installation of a common row of anchors. RECP ends shall be shingled. Refer to the Contract Drawings and/or the Manufacturer’s installation guidelines/instructions for installation details. 5. Maintenance: Maintenance of RECPs shall be in accordance with Section 02270, Erosion and Sedimentation Control, of these Specifications. Table 1: Required Rolled Erosion Control Product Properties Property Test Method Units Value1 Erosion Control Blanket (ECB) (Single Net) Mass per Unit Area ASTM D 6475 lbs/yd2 0.5 + 10% (Straw) 0.7 + 10% (Excelsior) Tensile Strength2 ASTM D 6818 lbs/ft 50 x 65 Tensile Elongation ASTM D 6818 % 20 Maximum Permissible Shear Stress (Un-Vegetated) ----- lbs/ft2 1.55 Functional Longevity ----- months 12 Erosion Control Blanket (ECB) (Double Net) Mass per Unit Area ASTM D 6475 lbs/yd2 0.5 + 10% (Straw) 0.7 + 10% (Excelsior) Tensile Strength2 ASTM D 6818 lbs/ft 75 x 75 Tensile Elongation ASTM D 6818 % 25 Maximum Permissible Shear Stress (Un-Vegetated) ----- lbs/ft2 1.75 Functional Longevity ----- months 12 Notes: 1. Typical for ECB; Minimum Average Roll Value (MARV) for TRM and HPTRM. 2. Values for machine and cross machine direction (MD x XD), respectively. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Precast Concrete Structures Page 02608-1 SECTION 02608 PRECAST CONCRETE STRUCTURES A. Description 1. General: The Contractor shall furnish all labor, material, and equipment to complete installation of Precast Concrete Structures in accordance with the Contract Drawings and these Specifications. 2. Related Work: Related Contract Work is described in the following sections of the Specifications: Work Section Excavation 02222 Embankment 02223 Erosion and Sedimentation Control 02270 Stormwater Systems 02720 3. Reference Standards: The latest revision of the following standards of the American Society of Testing and Materials (ASTM) are hereby made a part of these Specifications. ASTM A 615 Standard Specification for Deformed and Plain Billet-Steel Bars for Concrete Reinforcement. ASTM C 443 Standard Specification for Joints for Circular Concrete Sewer and Culvert Pipe, Using Rubber Gaskets. ASTM C 478 Standard Specification for Precast Reinforced Concrete Manhole Sections. ASTM C 497 Standard Test Methods for Concrete Pipe, Manhole Sections, or Tile. ASTM C 990 Standard Specification for Joints for Concrete Pipe, Manholes, and Precast Box Sections Using Preformed Flexible Joint Sealants. ASTM C 1433 Standard Specification for Precast Reinforced Concrete Box Sections for Culverts, Strom Drains, and Sewers. Precast Concrete Structures: Precast Concrete Structures are used in the stormwater management. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Precast Concrete Structures Page 02608-2 B. Materials 1. Precast Concrete Boxes: All precast concrete boxes shall be constructed from non- shrink, 4,000 psi compressive strength concrete in conformance with ASTM C 1433 and as detailed on the Contract Drawings. 2. Joints: All joints shall be sealed with preformed plastic gaskets in conformance with ASTM C 990 or rubber gaskets in conformance with ASTM C 443. 3. Steps: All steps shall be constructed of 0.5 inch reinforcing rod completely encased in corrosion-resistant rubber or plastic. The upper surfaces of each step shall have a traction tread of self cleaning rubber cleats and guide lugs on both sides to prevent slippage. 4. Frames and Covers: Frames and covers shall consist of cast iron frames and covers (Vulcan Foundry, or equal) equipped with steel handles and shall be of the opening size as indicated on the Contract Drawings. Markings on the covers shall indicate the intended use of the structure and shall be acceptable to the Owner. 5. Markings: All Precast Concrete Structures shall include markings clearly identifying the date of manufacture, the name of the manufacturer, and any other pertinent information. C. Submittals The Contractor shall submit the following to the Engineer: 1. The Contractor shall submit shop drawings for Precast Concrete Structures for approval at least 4 weeks prior to construction. Shop drawings shall show complete design, installation, and construction information in such detail as to enable the Engineer to determine the adequacy of the proposed units for the intended purpose. Details of steel reinforcement size and placement shall be included. The shop drawings shall include a schedule which will list the size and type of precast structure at each location where the precast structures are to be used. 2. Submit a certification and summary of all required test results, prior to installation, that all Precast Concrete Structures have been produced in accordance with these Specifications. D. Construction 1. The Precast Concrete Structures shall be installed at the locations and to the elevations indicated on the Contract Drawings. The Contractor shall give the Engineer sufficient notice so they may observe the field location and installation activities. 2. The Precast Concrete Structures will be bedded and backfilled as indicated on the Contract Drawings. 3. Precast Concrete Structures which are damaged or become damaged will be rejected or shall be repaired in a manner approved by the Engineer at the Contractor’s sole expense. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Precast Concrete Structures Page 02608-3 END OF SECTION DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 This page intentionally left blank. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Stormwater Systems Page 02720-1 SECTION 02720 STORMWATER SYSTEMS A. Description 1. General: The contractor shall furnish all labor, material, and equipment to complete installation of Stormwater Systems in accordance with the Contract Drawings and these Specifications. 2. Related Work: Related Contract Work is described in the following sections of the Specifications: Work Section Excavation 02222 Embankment 02223 Erosion and Sedimentation Control 02270 Rip Rap 02271 Precast Concrete Structures 02608 3. Reference Standards: The latest revision of the following standards of the American Society of Testing and Materials (ASTM), the American Association of State Highway and Transportation Officials (AASHTO), and the North Carolina Department of Transportation (NCDOT) are hereby made a part of these specifications. ASTM C 76 Standard Specification for Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe. ASTM C 150 Standard Specification for Portland Cement. ASTM D 1248 Standard Specification for Polyethylene Plastics Molding and Extrusion Materials For Wire and Cable. ASTM D 2321 Standard Practice for Underground Installation of Thermoplastic Pipe for Sewers and Other Gravity-Flow Applications. ASTM D 3350 Standard Specification for Polyethylene Plastics Pipe and Fittings Materials. AASHTO M 36 Specification for Corrugated Steel Pipe. Stormwater Systems: Stormwater Systems shall include all piping, pipe fittings, headwalls, flared end sections, and other appurtenances designated to convey stormwater. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Stormwater Systems Page 02720-2 AASHTO M 252 Specification for Corrugated Polyethylene Drainage Tubing, 3 to 10 Inch Diameter. AASHTO M 294 Specification for Corrugated Polyethylene Pipe, 12 to 36 Inch Diameter. NCDOT Standard Specifications for Roads and Structures and Roadway Standard Drawings. B. Materials 1. Corrugated Polyethylene (CPE) Pipe: CPE pipe and fittings shall be of the sizes and type shown on the Contract Drawings and shall conform to every aspect of AASHTO M 252 (3 to 10 inch diameters) or AASHTO M 294 (12 to 36 inch diameters). All Type S CPE pipe shall have watertight joints. 2. Flared End Sections: Flared end sections shall be reinforced and shall be fabricated from the same materials meeting the same requirements as the pipe to which they are connected. All reinforced concrete and corrugated metal flared end sections shall meet the requirements of the NCDOT. Corrugated polyethylene flared end sections shall be as recommended by the pipe manufacturer. 3. Precast Concrete Structures: Precast Concrete Structures shall be constructed as shown in the Contract Drawings and in accordance with Section 02608, Precast Concrete Structures, of these Specifications. C. Submittals The Contractor shall submit the following to the Engineer: 1. Submit a certification and summary of all required test results, prior to installation, that all Stormwater Systems have been produced in accordance with these Specifications. 2. Furnish copies of the delivery tickets or other approved receipts as evidence for materials received that will be incorporated into construction. D. Construction 1. All piping shall be installed by skilled workmen and in accordance with the best standards for piping installation. Proper tools and appliances for the safe and convenient handling and installation of the pipe and fittings shall be used. 2. All pieces shall be carefully examined for defects, and no piece shall be installed which is known to be defective. If any defective piece should be discovered after having been installed, it shall be removed and replaced at the Contractor's expense. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Stormwater Systems Page 02720-3 3. Prior to installation, the Contractor is responsible for checking the fit of design elevations for Stormwater Systems with existing conditions (i.e. conflicts with other structures, fit within existing drainage channels/features, ability to have minimum cover, etc.). The Contractor shall notify the Engineer of any conflicts and/or necessary field adjustments prior to installation for resolution or concurrence. 4. Excavation and backfilling of pipe trenches shall be as described in Section 02222, Excavation and Section 02223, Embankment, respectively, of these Specifications. 5. Following proper preparation of the trench subgrade, pipe and fittings shall be carefully lowered into the trench so as to prevent dirt and other foreign substances from gaining entrance into the pipe and fittings. Proper facilities shall be provided for lowering sections of pipe into trenches. No materials shall be dropped or dumped into the trench. 6. Water shall be kept out of the trench until jointing and backfilling are completed. When work is not in progress, open ends of pipe, fittings, and valves shall be securely closed so that no water, earth, or other substance will enter the pipes, fittings, or valves. Pipe ends left for future connections shall be valved, plugged, or capped, and anchored as required. 7. All Stormwater Systems shall be installed to accurate lines and grades with no abrupt changes in line or grade. 8. The full length of each section of pipe shall rest solidly upon the bed of the trench, with recesses excavated to accommodate bells, couplings, joints, and fittings. Before joints are made, each pipe shall be well bedded on a solid foundation. No pipe shall be brought into position until the preceding length has been thoroughly bedded and secured in place. Pipe that has the grade or joint disturbed after laying shall be taken up and re-laid by the Contractor at their own expense. END OF SECTION DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 This page intentionally left blank. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Revegetation Page 02930-1 SECTION 02930 REVEGETATION A. Description 1. General: The Contractor shall furnish all labor, material, and equipment to complete Revegetation in accordance with the Contract Drawings and these Specifications. 2. Related Work: Related Contract Work is described in the following sections of the Specifications: Work Section Excavation 02222 Embankment 02223 Erosion and Sedimentation Control 02270 Rolled Erosion Control Products 02275 3. Correction Period: The Contractor shall be responsible for the satisfactory establishment and growth of a permanent stand of vegetation as judged by the Engineer during the correction period of the Contract (Alternatively, if no correction period is defined in the Contract, the correction period shall be one year after substantial completion of the project.). During this period, the Contractor shall be responsible for the maintenance items described in Paragraph D.4 (Maintenance) of this Specification. B. Materials 1. Limestone: Unless otherwise defined by specific soil tests, supply agricultural grade ground limestone conforming to the current “Rules, Regulations, and Standards of the Fertilizer Board of Control.” 2. Fertilizer: Unless otherwise defined by specific soil tests, supply commercial fertilizer meeting applicable requirements of State and Federal law. Do not use cyanamic compounds of hydrated lime. Deliver fertilizer in original containers labeled with content analysis. 3. Grass Seed: Supply fresh, clean, new-crop seed. Do not use seed which is wet, moldy, or otherwise damaged. Deliver seed in standard sealed containers labeled with producer’s Revegetation: Revegetation includes permanent Revegetation of all site areas disturbed by the Contractor whether inside the Contract Limits or not. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Revegetation Page 02930-2 name and seed analysis, and in accord with US Department of Agriculture Rules and Regulations under Federal Seed Act. 4. Mulch: Supply clean, seed-free, threshed straw of oats, wheat, barley, rye, beans, or other locally available mulch material. a. Do not use mulch containing a quantity of matured, noxious weed seeds or other species that will be detrimental to seeding, or provide a menace to surrounding land. b. Do not use mulch material which is fresh or excessively brittle, or which is decomposed and will smother or retard growth of grass. 5. Binder: Supply emulsified asphalt or synthetic binder. 6. Water: Supply potable, free of substances harmful to growth. 7. Application rates, seed types, and other requirements shall be in accordance with Table 1 of this section. C. Submittals The Contractor shall submit the following to the Engineer: 1. Results of soil tests performed and proposed modifications, if any, to the specified requirements. 2. Certificates for each grass seed mixture, stating botanical and common name, percentage by weight, and percentages of purity, germination, and weed seed. Certify that each container of seed delivered is fully labeled in accordance with Federal Seed Act and equals or exceeds specification requirements. 3. Copies of invoices for fertilizer, showing grade furnished and total quantity applied. D. Construction 1. The Contractor shall establish a smooth, healthy, uniform, close stand of grass from the specified seed. Prior to Revegetation, the Contractor shall adequately test the soils to be revegetated to ensure the adequacy of the specified requirements. Any modifications to these requirements deemed necessary after the review of soil test results, shall be at the Contractor’s sole expense. The Engineer will perform the observations to determine when successful Revegetation is achieved. 2. Soil Preparation: a. Limit preparation to areas which will be planted soon after preparation. b. Loosen surface to minimum depth of four (4) inches. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Revegetation Page 02930-3 c. Remove stones, sticks, roots, rubbish and other extraneous matter over three (3) inches in any dimension. d. Spread lime uniformly over designated areas at the rate specified in Table 1 of this section. e. After application of lime, prior to applying fertilizer, loosen areas to be seeded with double disc or other suitable device if soil has become hard or compacted. Correct any surface irregularities in order to prevent pocket or low areas which will allow water to stand. f. Distribute fertilizer uniformly over areas to be seeded at the rate specified in Table 1 of this section. (1) Use suitable distributor. (2) Incorporate fertilizer into soil to depth of at least two (2) inches. (3) Remove stones or other substances which will interfere with turf development or subsequent mowing. g. Grade seeded areas to smooth, even surface with loose, uniformly fine texture. (1) Roll and rake, remove ridges and fill depressions, as required to meet finish grades. (2) Fine grade just prior to planting. 3. Seeding: a. Use approved mechanical power driven drills or seeders, mechanical hand seeders, or other approved equipment. b. Distribute seed evenly over entire area at the rate specified in Table 1 of this section. c. Stop work when work extends beyond most favorable planting season for species designated, or when satisfactory results cannot be obtained because of drought, high winds, excessive moisture, or other factors. d. Resume work only when favorable condition develops, or as directed by the Engineer. e. Lightly rake seed into soil followed by light rolling or cultipacking. f. Immediately protect seeded areas against erosion by mulching or placing Rolled Erosion Control Products in accordance with Section 02275 of these Specifications, where applicable. DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Revegetation Page 02930-4 (1) Spread mulch in a continuous blanket at the rate specified in Table 1 of this section. (2) Immediately following spreading mulch, secure with evenly distributed binder at the rate specified in Table 1 of this section. (3) For slopes not steeper than 3H:1V and as an option to using binder to secure mulch, use a mulch anchoring tool operated along the contour of the slope. 4. Maintenance: The Contractor shall be responsible for maintaining all seeded areas through the end of their warranty period. The Contractor shall provide, at their expense, protection of all seeded areas against damage at all times until acceptance of the work. Maintenance shall include, but not be limited to, the following items: a. Regrade and revegetate all eroded areas until adequately stabilized by grass. b. Remulch with new mulch in areas where mulch has been disturbed by wind or maintenance operations sufficiently to nullify its purpose. Anchor as required to prevent displacement. c. Replant bare areas using same materials specified. Table 1: Seeding Schedule Material Seed Type Application Rate (See Note 1) Lime ----- 4,000 lbs/acre Fertilizer (10-10-10) ----- 500 lbs/acre Seed: Permanent: Tall Fescue Pensacola Bahiagrass Bermudagrass3 Seasonal Nurse Crop2 50 lbs/acre 50 lbs/acre 35 lbs/acre See Note 2 Temporary: Seasonal Nurse Crop2 See Note 2 Mulch ----- 4,000 - 5,000 lbs/acre Binder ----- 400 gallons/acre DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 SR&R Environmental – Laydown Yard Technical Specifications October 2023 Revegetation Page 02930-5 Notes: 1. Application rates and/or chemical analysis shall be confirmed or established by a soil test(s). 2. Use seasonal nurse crop in accordance with seeding dates as stated below: March 1 - August 31 10 lbs/acre German Millet or 15 lbs/acre Sudangrass September 1 – February 28 25 lbs/acre Rye (grain). 3. From September 1 - March 1, use unhulled Bermudagrass seed. END OF SECTION DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635 DocuSign Envelope ID: 150C722E-3955-4DB3-8D0B-EAB4D64C91F8DocuSign Envelope ID: 41FF8FC5-7A79-476A-9176-8350D9E2B245DocuSign Envelope ID: 2BC8C10A-28C9-4626-9349-4F8BB660F635