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Sheetz Shade Tree - Stormwater Report STORMWATER REPORT SHEETZ – SHADE TREE LANE WILMINGTON, NORTH CAROLINA MAY 15, 2024 PREPARED FOR: Sheetz, Inc. 5700 Sixth Avenue Altoona, PA 16602 PREPARED BY: Timmons Group, NC License No. 023728 5410 Trinity Road, Suite 102 Raleigh, North Carolina 27607 www.timmons.com Sheetz – Shade Tree Lane Wilmington, NC Project Number: 64250.002 Table of Contents Stormwater Narrative ......................................................................................................................................... 1 Project Background ........................................................................................................................................ 1 Proposed Project Description ......................................................................................................................... 1 Proposed Stormwater Management ............................................................................................................... 1 Stormwater Runoff Control ......................................................................................................................... 1 TSS Removal ............................................................................................................................................. 1 Seasonal High Water Table ........................................................................................................................ 1 Methodology for Stormwater Modeling ....................................................................................................... 2 Hydrology ................................................................................................................................................... 2 Hydraulics .................................................................................................................................................. 2 Pre & Post Development Runoff Summary ................................................................................................. 2 Reference Material ............................................................................................................................................ 3 SHWT Report................................................................................................................................................. 3 NOAA Rainfall Data ....................................................................................................................................... 3 National Wetlands Inventory Map................................................................................................................... 3 USGS Map ..................................................................................................................................................... 3 FEMA Map ..................................................................................................................................................... 3 Soil Survey Map ............................................................................................................................................. 3 Pre/Post Development Drainage Area Maps .................................................................................................. 3 Peak Flow Analysis ........................................................................................................................................... 4 Worksheet – SCS Curve Numbers ................................................................................................................. 4 Hydraflow Report ........................................................................................................................................... 4 Water Quality Calculations ................................................................................................................................ 5 Contech Design Worksheets .......................................................................................................................... 5 Stormwater Operation & Maintenance Agreement ............................................................................................. 6 Hydraulic Grade Line Calculations ..................................................................................................................... 7 Q10 Analysis Using Hydraflow Software ........................................................................................................ 7 Q25 Analysis Using Hydraflow Software ........................................................................................................ 7 Sheetz – Shade Tree Lane Wilmington, NC Project Number: 64250.002 1 | www.timmons.com Stormwater Narrative Project Background The Sheetz – Shade Tree Lane project is located at 4915 Carolina Beach Road, Wilmington, North Carolina. The property identification number (PIN) is as follows: • R07100-003-024-000 The site consists of approximately 4.4 acres and is currently occupied by a landscaping company. The property will be subdivided, and the resulting Sheetz property will be 2.76 acres (after ROW dedication). FIRM Panel 3720313400K indicates the site is not within a special flood hazard area. There is an existing jurisdictional stream on the property. Permits will be obtained to remove this stream. Proposed Project Description This project proposes a new 6,139 SF convenience store and gas canopy with associated parking lot and utilities. There is approximately 0.56 AC of existing impervious cover within the existing property boundary, with 0.46 acres of impervious on the subdivided Sheetz parcel. The proposed improvements will result in a post- developed impervious cover of 2.01 AC (including 0.1 ac (4,356 SF) future impervious), which includes 1.71 ac of impervious on the Sheetz parcel. The post-developed impervious percentage on the Sheetz parcel (post- ROW dedication) is 62%. Proposed Stormwater Management This site has been graded to maintain similar drainage patterns to the existing conditions. To the maximum extent practical, the onsite impervious areas are directed toward the proposed underground detention and StormFilter SCM. Stormwater Runoff Control A Contech underground detention & StormFilter system is proposed to improve the quantity and quality of stormwater runoff for the site in compliance with the rules contained in the New Hanover County Design Manual. The SCM has been designed for 85% TSS removal in accordance with the NCDENR BMP Manual. Since the existing impervious is sheet flowing off the site, we are providing greater stormwater control by reducing the area of uncontrolled runoff from the site. TSS Removal The NCDEQ Stormwater Design Manual requirement of 85% Total Suspended Solid removal requirement has been exceeded by the proposed underground detention and StormFilter SCM. Seasonal High Water Table A seasonal high water table investigation was performed by ECS Southeast, LLC. The attached report indicates that at the location of the SCM, the SHWT is 16-18” below existing grade. See the attached report for more detailed information. Due to the proximity of the SHWT, a clay liner and concrete slab for anti-buoyancy will be provided for the Contech SCM. Sheetz – Shade Tree Lane Wilmington, NC Project Number: 64250.002 2 | www.timmons.com Methodology for Stormwater Modeling A pre-development and post-development hydrologic analysis was completed for the site using the SCS TR20 method. A hydraulic analysis was completed using Hydraflow modeling software to route these storm events through the proposed underground detention and outlet structure. Hydrology The SCS TR20 method was used to determine the peak discharge rates for the pre-development and post- development conditions, develop runoff hydrographs and size the detention storage for the SCM. Rainfall data used in the design was taken from published NOAA data for the City of Wilmington. SCS runoff curve numbers were based on Table 2-2 in the TR55 manual. The Time of Concentration (Tc) values were determined using the TR55 method for sheet, shallow and concentrated flows, with a minimum Tc of 5 minutes. Hydraulics Computer simulated reservoir routing using Hydraflow modeling software was completed for the 1-year, 2-year, 10-year, 25-year, and 100-year storm events utilizing stage-storage and stage-discharge functions. Stage- storage was determined using the dimensions of the detention system and stage-discharge functions were developed using the proposed outlet structures. The outlet structures were designed to attenuate the post- development discharge rates for the 1, 2, 10, and 25-year storm events equal to or less than pre-development levels. Pre & Post Development Runoff Summary Site Condition Storm Event (cfs) 1-year (cfs) 2-year (cfs) 10-year (cfs) 25-year (cfs) 100-year (cfs) Pre-Development 7.751 10.37 18.86 25.03 36.80 Post- Development without Detention 10.09 12.76 21.29 27.49 39.38 Post- Development with Detention 5.900 9.724 18.02 23.63 35.13 Sheetz – Shade Tree Lane Wilmington, NC Project Number: 64250.002 3 | www.timmons.com Reference Material SHWT Report NOAA Rainfall Data National Wetlands Inventory Map USGS Map FEMA Map Soil Survey Map Pre/Post Development Drainage Area Maps January 17, 2024 Mr. Richard Collier, PE McKim & Creed 243 North Front Street Wilmington, North Carolina 28401 Reference: Report of Seasonal High Water Table Estimation and Infiltration Testing Sheetz Shade Tree Wilmington, New Hanover County, North Carolina ECS Project No. 49.22135 Dear Mr. Collier: ECS Southeast, LLC (ECS) recently conducted a seasonal high water table (SHWT) estimation and infiltration testing within the stormwater control measure (SCM) area(s) at the intersection of Shade Tree Lane and Carolina Beach Road in Wilmington, New Hanover County, North Carolina. This letter, with attachments, is the report of our testing. Field Testing On January 16, 2024, ECS conducted an exploration of the subsurface soil and groundwater conditions, in accordance with the NCDEQ Stormwater Design Manual section A-2, at two requested locations shown on the attached Boring Location Plan (Figure 1). The boring locations were surveyed prior to ECSs site visit. The purpose of this exploration was to obtain subsurface information of the in situ soils for the SCM area(s). ECS explored the subsurface soil and groundwater conditions by advancing one hand auger boring into the existing ground surface at each of the requested boring locations. ECS visually classified the subsurface soils and obtained representative samples of each soil type encountered. ECS also recorded the SHWT and groundwater elevation observed at the time of the hand auger borings. The attached Infiltration Testing Form provides a summary of the subsurface conditions encountered at the hand auger boring locations. The SHWT and groundwater elevation was estimated at the boring locations below the existing grade elevation. A summary of the findings are as follows: Location SHWT Groundwater I-1 18 inches 36 inches I-2 16 inches 32 inches ECS has conducted two infiltration tests utilizing a compact constant head permeameter near the hand auger borings in order to estimate the infiltration rate for the subsurface soils. Infiltration tests are typically conducted at two feet above the SHWT or in the most restrictive soil horizon Tests in clayey conditions are conducted for durations of up to 30 minutes. If a more precise hydraulic conductivity value is desired for these locations, then ECS recommends collecting samples and performing laboratory permeability testing. Report of SHWT Estimation and Infiltration Testing Sheetz Shade Tree Wilmington, New Hanover County, North Carolina ECS Project No. 49.22135 January 17, 2024 2 Field Test Results Below is a summary of the infiltration test results: Location Description Depth Inches/ hour I-1 Gray/orange sandy CLAY 24 inches <0.001 I-2 Black silty SAND 12 inches 0.03 Infiltration rates and SHWT may vary within the proposed site due to changes in elevation, soil classification and subsurface conditions. ECS recommends that a licensed surveyor provide the elevations of the boring locations. Closure ECS’s analysis of the site has been based on our understanding of the site, the project information provided to us, and the data obtained during our exploration. If the project information provided to us is changed, please contact us so that our recommendations can be reviewed and appropriate revisions provided, if necessary. The discovery of any site or subsurface conditions during construction which deviate from the data outlined in this exploration should be reported to us for our review, analysis and revision of our recommendations, if necessary. The assessment of site environmental conditions for the presence of pollutants in the soil and groundwater of the site is beyond the scope of this geotechnical exploration. ECS appreciates the opportunity to provide our services to you on this project. If you have any questions concerning this report or this project, please contact us. Respectfully, ECS SOUTHEAST, LLC K. Brooks Wall W. Brandon Fulton, PSC, PWS, LSS Project Manager Environmental Department Manager bwall@ecslimited.com bfulton@ecslimited.com 910-686-9114 704-525-5152 Attachments: Figure 1 - Boring Location Plan Infiltration Testing Form GBA Document APPROXIMATE BORING LOCATIONS SCALE SHOWN ABOVE Sheetz Shade Tree Wilmington, New Hanover County, North Carolina ECS Project # 49.22135 January 16, 2024 KBW Figure 1–Boring Location Plan Provided by: Mckim & Creed I-1 I-2 N W S E N W S E Infiltration Testing Form Sheetz Shade Tree Wilmington, New Hanover County, North Carolina ECS Project No. 49.22135 January 16, 2024 Location Depth USCS Soil Description I-1 0-18” SM Black silty SAND 18”-24” SC Gray clayey SAND 24”-36” SC Gray/orange sandy CLAY Seasonal High Water Table was estimated to be at 18 inches below the existing grade elevation. Groundwater was observed to be at 36 inches below the existing grade elevation. Test was conducted at 24 inches below existing grade elevation Infiltration Rate: <0.001 inches per hour Location Depth USCS Soil Description I-2 0-36” SM Black silty SAND 36”-48” SC Gray/orange sandy CLAY Seasonal High Water Table was estimated to be at 16 inches below the existing grade elevation. Groundwater was observed to be at 32 inches below the existing grade elevation. Test was conducted at 12 inches below existing grade elevation Infiltration Rate: 0.03 inches per hour Geotechnical-Engineering Report Important Information about This Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes. While you cannot eliminate all such risks, you can manage them. The following information is provided to help. The Geoprofessional Business Association (GBA) has prepared this advisory to help you – assumedly a client representative – interpret and apply this geotechnical-engineering report as effectively as possible. In that way, clients can benefit from a lowered exposure to the subsurface problems that, for decades, have been a principal cause of construction delays, cost overruns, claims, and disputes. If you have questions or want more information about any of the issues discussed below, contact your GBA-member geotechnical engineer. Active involvement in the Geoprofessional Business Association exposes geotechnical engineers to a wide array of risk-confrontation techniques that can be of genuine benefit for everyone involved with a construction project. Geotechnical-Engineering Services Are Performed for Specific Purposes, Persons, and ProjectsGeotechnical engineers structure their services to meet the specific needs of their clients. A geotechnical-engineering study conducted for a given civil engineer will not likely meet the needs of a civil-works constructor or even a different civil engineer. Because each geotechnical-engineering study is unique, each geotechnical-engineering report is unique, prepared solely for the client. Those who rely on a geotechnical-engineering report prepared for a different client can be seriously misled. No one except authorized client representatives should rely on this geotechnical-engineering report without first conferring with the geotechnical engineer who prepared it. And no one – not even you – should apply this report for any purpose or project except the one originally contemplated. Read this Report in FullCostly problems have occurred because those relying on a geotechnical-engineering report did not read it in its entirety. Do not rely on an executive summary. Do not read selected elements only. Read this report in full. You Need to Inform Your Geotechnical Engineer about ChangeYour geotechnical engineer considered unique, project-specific factors when designing the study behind this report and developing the confirmation-dependent recommendations the report conveys. A few typical factors include: • the client’s goals, objectives, budget, schedule, and risk-management preferences; • the general nature of the structure involved, its size, configuration, and performance criteria; • the structure’s location and orientation on the site; and • other planned or existing site improvements, such as retaining walls, access roads, parking lots, and underground utilities. Typical changes that could erode the reliability of this report include those that affect: • the site’s size or shape; • the function of the proposed structure, as when it’s changed from a parking garage to an office building, or from a light-industrial plant to a refrigerated warehouse; • the elevation, configuration, location, orientation, or weight of the proposed structure; • the composition of the design team; or • project ownership. As a general rule, always inform your geotechnical engineer of project changes – even minor ones – and request an assessment of their impact. The geotechnical engineer who prepared this report cannot accept responsibility or liability for problems that arise because the geotechnical engineer was not informed about developments the engineer otherwise would have considered. This Report May Not Be ReliableDo not rely on this report if your geotechnical engineer prepared it: • for a different client; • for a different project; • for a different site (that may or may not include all or a portion of the original site); or • before important events occurred at the site or adjacent to it; e.g., man-made events like construction or environmental remediation, or natural events like floods, droughts, earthquakes, or groundwater fluctuations. Note, too, that it could be unwise to rely on a geotechnical-engineering report whose reliability may have been affected by the passage of time, because of factors like changed subsurface conditions; new or modified codes, standards, or regulations; or new techniques or tools. If your geotechnical engineer has not indicated an “apply-by” date on the report, ask what it should be, and, in general, if you are the least bit uncertain about the continued reliability of this report, contact your geotechnical engineer before applying it. A minor amount of additional testing or analysis – if any is required at all – could prevent major problems. Most of the “Findings” Related in This Report Are Professional Opinions Before construction begins, geotechnical engineers explore a site’s subsurface through various sampling and testing procedures. Geotechnical engineers can observe actual subsurface conditions only at those specific locations where sampling and testing were performed. The data derived from that sampling and testing were reviewed by your geotechnical engineer, who then applied professional judgment to form opinions about subsurface conditions throughout the site. Actual sitewide-subsurface conditions may differ – maybe significantly – from those indicated in this report. Confront that risk by retaining your geotechnical engineer to serve on the design team from project start to project finish, so the individual can provide informed guidance quickly, whenever needed. This Report’s Recommendations Are Confirmation-DependentThe recommendations included in this report – including any options or alternatives – are confirmation-dependent. In other words, they are not final, because the geotechnical engineer who developed them relied heavily on judgment and opinion to do so. Your geotechnical engineer can finalize the recommendations only after observing actual subsurface conditions revealed during construction. If through observation your geotechnical engineer confirms that the conditions assumed to exist actually do exist, the recommendations can be relied upon, assuming no other changes have occurred. The geotechnical engineer who prepared this report cannot assume responsibility or liability for confirmation-dependent recommendations if you fail to retain that engineer to perform construction observation. This Report Could Be MisinterpretedOther design professionals’ misinterpretation of geotechnical-engineering reports has resulted in costly problems. Confront that risk by having your geotechnical engineer serve as a full-time member of the design team, to: • confer with other design-team members, • help develop specifications, • review pertinent elements of other design professionals’ plans and specifications, and • be on hand quickly whenever geotechnical-engineering guidance is needed. You should also confront the risk of constructors misinterpreting this report. Do so by retaining your geotechnical engineer to participate in prebid and preconstruction conferences and to perform construction observation. Give Constructors a Complete Report and GuidanceSome owners and design professionals mistakenly believe they can shift unanticipated-subsurface-conditions liability to constructors by limiting the information they provide for bid preparation. To help prevent the costly, contentious problems this practice has caused, include the complete geotechnical-engineering report, along with any attachments or appendices, with your contract documents, but be certain to note conspicuously that you’ve included the material for informational purposes only. To avoid misunderstanding, you may also want to note that “informational purposes” means constructors have no right to rely on the interpretations, opinions, conclusions, or recommendations in the report, but they may rely on the factual data relative to the specific times, locations, and depths/elevations referenced. Be certain that constructors know they may learn about specific project requirements, including options selected from the report, only from the design drawings and specifications. Remind constructors that they may perform their own studies if they want to, and be sure to allow enough time to permit them to do so. Only then might you be in a position to give constructors the information available to you, while requiring them to at least share some of the financial responsibilities stemming from unanticipated conditions. Conducting prebid and preconstruction conferences can also be valuable in this respect. Read Responsibility Provisions Closely Some client representatives, design professionals, and constructors do not realize that geotechnical engineering is far less exact than other engineering disciplines. That lack of understanding has nurtured unrealistic expectations that have resulted in disappointments, delays, cost overruns, claims, and disputes. To confront that risk, geotechnical engineers commonly include explanatory provisions in their reports. Sometimes labeled “limitations,” many of these provisions indicate where geotechnical engineers’ responsibilities begin and end, to help others recognize their own responsibilities and risks. Read these provisions closely. Ask questions. Your geotechnical engineer should respond fully and frankly. Geoenvironmental Concerns Are Not Covered The personnel, equipment, and techniques used to perform an environmental study – e.g., a “phase-one” or “phase-two” environmental site assessment – differ significantly from those used to perform a geotechnical-engineering study. For that reason, a geotechnical- engineering report does not usually relate any environmental findings, conclusions, or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Unanticipated subsurface environmental problems have led to project failures. If you have not yet obtained your own environmental information, ask your geotechnical consultant for risk-management guidance. As a general rule, do not rely on an environmental report prepared for a different client, site, or project, or that is more than six months old. Obtain Professional Assistance to Deal with Moisture Infiltration and Mold While your geotechnical engineer may have addressed groundwater, water infiltration, or similar issues in this report, none of the engineer’s services were designed, conducted, or intended to prevent uncontrolled migration of moisture – including water vapor – from the soil through building slabs and walls and into the building interior, where it can cause mold growth and material-performance deficiencies. Accordingly, proper implementation of the geotechnical engineer’s recommendations will not of itself be sufficient to prevent moisture infiltration. Confront the risk of moisture infiltration by including building-envelope or mold specialists on the design team. Geotechnical engineers are not building-envelope or mold specialists. Copyright 2016 by Geoprofessional Business Association (GBA). Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly prohibited, except with GBA’s specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission of GBA, and only for purposes of scholarly research or book review. Only members of GBA may use this document or its wording as a complement to or as an element of a report of any kind. Any other firm, individual, or other entity that so uses this document without being a GBA member could be committing negligent Telephone: 301/565-2733 e-mail: info@geoprofessional.org www.geoprofessional.org NOAA Atlas 14, Volume 2, Version 3 Location name: Wilmington, North Carolina, USA* Latitude: 34.1511°, Longitude: -77.9024° Elevation: 17 ft** * source: ESRI Maps** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley NOAA, National Weather Service, Silver Spring, Maryland PF_tabular | PF_graphical | Maps_&_aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 5-min 0.530 (0.494‑0.572) 0.630 (0.587‑0.680) 0.737 (0.685‑0.793) 0.819 (0.759‑0.883) 0.925 (0.853‑0.994) 1.00 (0.922‑1.08) 1.09 (0.991‑1.17) 1.17 (1.06‑1.26) 1.27 (1.14‑1.38) 1.36 (1.21‑1.47) 10-min 0.846 (0.789‑0.914) 1.01 (0.938‑1.09) 1.18 (1.10‑1.27) 1.31 (1.21‑1.41) 1.47 (1.36‑1.58) 1.60 (1.47‑1.72) 1.73 (1.58‑1.86) 1.85 (1.68‑1.99) 2.02 (1.81‑2.18) 2.14 (1.91‑2.32) 15-min 1.06 (0.986‑1.14) 1.27 (1.18‑1.37) 1.49 (1.39‑1.61) 1.66 (1.54‑1.79) 1.87 (1.72‑2.01) 2.02 (1.86‑2.18) 2.18 (1.99‑2.35) 2.34 (2.12‑2.52) 2.54 (2.28‑2.74) 2.69 (2.40‑2.91) 30-min 1.45 (1.35‑1.57) 1.75 (1.63‑1.89) 2.12 (1.97‑2.28) 2.40 (2.23‑2.59) 2.77 (2.55‑2.97) 3.05 (2.80‑3.28) 3.34 (3.05‑3.60) 3.64 (3.30‑3.92) 4.04 (3.62‑4.36) 4.36 (3.88‑4.72) 60-min 1.81 (1.68‑1.95) 2.20 (2.04‑2.37) 2.72 (2.53‑2.93) 3.13 (2.90‑3.37) 3.68 (3.40‑3.96) 4.13 (3.80‑4.45) 4.60 (4.20‑4.95) 5.10 (4.62‑5.49) 5.79 (5.20‑6.26) 6.36 (5.66‑6.89) 2-hr 2.14 (1.97‑2.34) 2.61 (2.40‑2.86) 3.32 (3.06‑3.63) 3.91 (3.59‑4.27) 4.76 (4.34‑5.19) 5.48 (4.97‑5.97) 6.26 (5.65‑6.82) 7.11 (6.37‑7.74) 8.38 (7.42‑9.13) 9.46 (8.31‑10.4) 3-hr 2.28 (2.10‑2.51) 2.78 (2.56‑3.06) 3.56 (3.26‑3.90) 4.22 (3.86‑4.62) 5.20 (4.72‑5.69) 6.05 (5.47‑6.62) 7.00 (6.27‑7.65) 8.05 (7.15‑8.78) 9.64 (8.46‑10.5) 11.0 (9.57‑12.1) 6-hr 2.85 (2.62‑3.14) 3.48 (3.20‑3.84) 4.45 (4.08‑4.91) 5.29 (4.83‑5.82) 6.55 (5.93‑7.18) 7.64 (6.88‑8.38) 8.87 (7.93‑9.71) 10.2 (9.05‑11.2) 12.3 (10.7‑13.5) 14.2 (12.2‑15.6) 12-hr 3.34 (3.04‑3.72) 4.08 (3.71‑4.53) 5.26 (4.77‑5.83) 6.28 (5.68‑6.95) 7.82 (7.01‑8.64) 9.19 (8.18‑10.1) 10.7 (9.47‑11.8) 12.5 (10.9‑13.7) 15.1 (13.0‑16.7) 17.5 (14.9‑19.3) 24-hr 3.94 (3.59‑4.38) 4.78 (4.36‑5.32) 6.18 (5.63‑6.88) 7.42 (6.73‑8.25) 9.33 (8.37‑10.4) 11.0 (9.80‑12.2) 13.0 (11.4‑14.4) 15.2 (13.1‑16.9) 18.6 (15.8‑20.8) 21.7 (18.0‑24.4) 2-day 4.62 (4.23‑5.10) 5.59 (5.12‑6.18) 7.17 (6.55‑7.94) 8.55 (7.78‑9.46) 10.7 (9.59‑11.8) 12.5 (11.2‑13.9) 14.6 (12.9‑16.3) 17.0 (14.8‑19.0) 20.6 (17.6‑23.2) 23.9 (19.9‑27.0) 3-day 4.90 (4.49‑5.40) 5.91 (5.42‑6.53) 7.54 (6.89‑8.32) 8.94 (8.14‑9.87) 11.1 (9.97‑12.2) 12.9 (11.5‑14.3) 15.0 (13.2‑16.6) 17.3 (15.1‑19.3) 20.9 (17.8‑23.4) 24.0 (20.2‑27.1) 4-day 5.17 (4.75‑5.69) 6.24 (5.73‑6.87) 7.90 (7.23‑8.71) 9.33 (8.50‑10.3) 11.5 (10.4‑12.6) 13.3 (11.9‑14.7) 15.3 (13.6‑17.0) 17.6 (15.4‑19.6) 21.1 (18.1‑23.6) 24.1 (20.4‑27.3) 7-day 5.91 (5.47‑6.44) 7.13 (6.60‑7.76) 8.96 (8.27‑9.77) 10.5 (9.66‑11.4) 12.7 (11.6‑13.9) 14.6 (13.3‑16.0) 16.7 (15.0‑18.3) 19.0 (16.8‑20.8) 22.3 (19.5‑24.7) 25.1 (21.6‑28.0) 10-day 6.66 (6.19‑7.22) 7.98 (7.40‑8.66) 9.89 (9.14‑10.7) 11.5 (10.6‑12.5) 13.8 (12.7‑15.0) 15.8 (14.4‑17.1) 17.9 (16.1‑19.5) 20.2 (18.0‑22.0) 23.5 (20.7‑25.9) 26.3 (22.8‑29.2) 20-day 8.92 (8.32‑9.59) 10.6 (9.92‑11.4) 12.9 (12.1‑13.9) 14.9 (13.8‑16.0) 17.6 (16.3‑18.9) 19.9 (18.2‑21.4) 22.3 (20.3‑24.1) 24.8 (22.4‑27.0) 28.4 (25.3‑31.1) 31.4 (27.6‑34.6) 30-day 11.0 (10.3‑11.7) 13.0 (12.3‑13.9) 15.7 (14.7‑16.7) 17.8 (16.7‑19.0) 20.7 (19.3‑22.1) 23.1 (21.4‑24.7) 25.5 (23.6‑27.4) 28.0 (25.7‑30.2) 31.5 (28.5‑34.2) 34.3 (30.8‑37.5) 45-day 13.6 (12.9‑14.5) 16.1 (15.2‑17.2) 19.1 (18.0‑20.4) 21.6 (20.2‑22.9) 24.9 (23.3‑26.5) 27.6 (25.7‑29.4) 30.3 (28.1‑32.4) 33.1 (30.5‑35.6) 37.0 (33.6‑39.9) 40.0 (36.1‑43.5) 60-day 16.4 (15.5‑17.4) 19.3 (18.3‑20.5) 22.6 (21.4‑24.0) 25.2 (23.8‑26.8) 28.8 (27.0‑30.5) 31.5 (29.5‑33.5) 34.2 (31.9‑36.5) 37.0 (34.3‑39.5) 40.6 (37.3‑43.7) 43.4 (39.6‑46.9) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical 5/9/24, 2:50 PM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=34.1511&lon=-77.9024&data=depth&units=english&series=pds 1/4 NOAA Atlas 14, Volume 2, Version 3 Location name: Wilmington, North Carolina, USA* Latitude: 34.1511°, Longitude: -77.9024° Elevation: 17 ft** * source: ESRI Maps** source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley NOAA, National Weather Service, Silver Spring, Maryland PF_tabular | PF_graphical | Maps_&_aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)1 Duration Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 5-min 6.36 (5.93‑6.86) 7.56 (7.04‑8.16) 8.84 (8.22‑9.52) 9.83 (9.11‑10.6) 11.1 (10.2‑11.9) 12.0 (11.1‑13.0) 13.0 (11.9‑14.0) 14.0 (12.7‑15.1) 15.3 (13.7‑16.5) 16.3 (14.5‑17.7) 10-min 5.08 (4.73‑5.48) 6.05 (5.63‑6.52) 7.08 (6.58‑7.63) 7.86 (7.28‑8.47) 8.84 (8.15‑9.50) 9.59 (8.81‑10.3) 10.4 (9.45‑11.1) 11.1 (10.1‑12.0) 12.1 (10.9‑13.1) 12.9 (11.4‑13.9) 15-min 4.23 (3.94‑4.57) 5.07 (4.72‑5.47) 5.97 (5.55‑6.43) 6.63 (6.14‑7.14) 7.47 (6.89‑8.03) 8.10 (7.44‑8.72) 8.72 (7.96‑9.39) 9.34 (8.46‑10.1) 10.1 (9.10‑11.0) 10.8 (9.58‑11.7) 30-min 2.90 (2.70‑3.13) 3.50 (3.26‑3.78) 4.24 (3.94‑4.57) 4.80 (4.45‑5.18) 5.53 (5.10‑5.95) 6.10 (5.60‑6.56) 6.68 (6.10‑7.19) 7.27 (6.59‑7.83) 8.07 (7.24‑8.72) 8.72 (7.76‑9.44) 60-min 1.81 (1.68‑1.95) 2.20 (2.04‑2.37) 2.72 (2.53‑2.93) 3.13 (2.90‑3.37) 3.68 (3.40‑3.96) 4.13 (3.80‑4.45) 4.60 (4.20‑4.95) 5.10 (4.62‑5.49) 5.79 (5.20‑6.26) 6.36 (5.66‑6.89) 2-hr 1.07 (0.985‑1.17) 1.31 (1.20‑1.43) 1.66 (1.53‑1.81) 1.96 (1.79‑2.13) 2.38 (2.17‑2.59) 2.74 (2.48‑2.98) 3.13 (2.82‑3.41) 3.56 (3.19‑3.87) 4.19 (3.71‑4.57) 4.73 (4.16‑5.18) 3-hr 0.760 (0.699‑0.835) 0.926 (0.852‑1.02) 1.18 (1.09‑1.30) 1.40 (1.28‑1.54) 1.73 (1.57‑1.89) 2.02 (1.82‑2.20) 2.33 (2.09‑2.55) 2.68 (2.38‑2.92) 3.21 (2.82‑3.50) 3.67 (3.18‑4.02) 6-hr 0.476 (0.437‑0.525) 0.580 (0.534‑0.641) 0.743 (0.681‑0.819) 0.884 (0.806‑0.972) 1.09 (0.990‑1.20) 1.28 (1.15‑1.40) 1.48 (1.32‑1.62) 1.71 (1.51‑1.87) 2.06 (1.79‑2.26) 2.37 (2.04‑2.60) 12-hr 0.277 (0.252‑0.308) 0.338 (0.307‑0.375) 0.436 (0.396‑0.484) 0.521 (0.471‑0.577) 0.649 (0.581‑0.717) 0.762 (0.679‑0.840) 0.890 (0.786‑0.980) 1.03 (0.904‑1.14) 1.26 (1.08‑1.38) 1.45 (1.23‑1.60) 24-hr 0.164 (0.149‑0.182) 0.199 (0.181‑0.221) 0.257 (0.234‑0.286) 0.309 (0.280‑0.343) 0.388 (0.348‑0.431) 0.459 (0.408‑0.509) 0.539 (0.474‑0.599) 0.632 (0.547‑0.703) 0.775 (0.656‑0.868) 0.902 (0.750‑1.02) 2-day 0.096 (0.088‑0.106) 0.116 (0.106‑0.128) 0.149 (0.136‑0.165) 0.178 (0.162‑0.197) 0.221 (0.199‑0.245) 0.260 (0.232‑0.289) 0.304 (0.268‑0.338) 0.353 (0.307‑0.395) 0.429 (0.365‑0.483) 0.496 (0.415‑0.562) 3-day 0.068 (0.062‑0.074) 0.082 (0.075‑0.090) 0.104 (0.095‑0.115) 0.124 (0.113‑0.137) 0.153 (0.138‑0.169) 0.179 (0.160‑0.198) 0.207 (0.183‑0.230) 0.240 (0.209‑0.267) 0.289 (0.247‑0.325) 0.333 (0.280‑0.376) 4-day 0.053 (0.049‑0.059) 0.064 (0.059‑0.071) 0.082 (0.075‑0.090) 0.097 (0.088‑0.107) 0.119 (0.107‑0.131) 0.138 (0.124‑0.152) 0.159 (0.141‑0.176) 0.183 (0.160‑0.203) 0.219 (0.188‑0.246) 0.251 (0.212‑0.284) 7-day 0.035 (0.032‑0.038) 0.042 (0.039‑0.046) 0.053 (0.049‑0.058) 0.062 (0.057‑0.068) 0.075 (0.069‑0.082) 0.087 (0.079‑0.095) 0.099 (0.089‑0.108) 0.112 (0.100‑0.123) 0.132 (0.115‑0.146) 0.149 (0.128‑0.166) 10-day 0.027 (0.025‑0.030) 0.033 (0.030‑0.036) 0.041 (0.038‑0.044) 0.047 (0.044‑0.051) 0.057 (0.052‑0.062) 0.065 (0.059‑0.071) 0.074 (0.067‑0.081) 0.084 (0.075‑0.091) 0.097 (0.086‑0.107) 0.109 (0.095‑0.121) 20-day 0.018 (0.017‑0.019) 0.022 (0.020‑0.023) 0.026 (0.025‑0.029) 0.030 (0.028‑0.033) 0.036 (0.033‑0.039) 0.041 (0.038‑0.044) 0.046 (0.042‑0.050) 0.051 (0.046‑0.056) 0.059 (0.052‑0.064) 0.065 (0.057‑0.072) 30-day 0.015 (0.014‑0.016) 0.018 (0.017‑0.019) 0.021 (0.020‑0.023) 0.024 (0.023‑0.026) 0.028 (0.026‑0.030) 0.032 (0.029‑0.034) 0.035 (0.032‑0.038) 0.038 (0.035‑0.041) 0.043 (0.039‑0.047) 0.047 (0.042‑0.052) 45-day 0.012 (0.011‑0.013) 0.014 (0.014‑0.015) 0.017 (0.016‑0.018) 0.019 (0.018‑0.021) 0.023 (0.021‑0.024) 0.025 (0.023‑0.027) 0.028 (0.025‑0.030) 0.030 (0.028‑0.032) 0.034 (0.031‑0.036) 0.037 (0.033‑0.040) 60-day 0.011 (0.010‑0.012) 0.013 (0.012‑0.014) 0.015 (0.014‑0.016) 0.017 (0.016‑0.018) 0.019 (0.018‑0.021) 0.021 (0.020‑0.023) 0.023 (0.022‑0.025) 0.025 (0.023‑0.027) 0.028 (0.025‑0.030) 0.030 (0.027‑0.032) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top PF graphical 5/9/24, 2:49 PM Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/pfds/pfds_printpage.html?lat=34.1511&lon=-77.9024&data=intensity&units=english&series=pds 1/4 Sheetz U.S. Fish and Wildlife Service, National Standards and Support Team,wetlands_team@fws.gov Wetlands Estuarine and Marine Deepwater Estuarine and Marine Wetland Freshwater Emergent Wetland Freshwater Forested/Shrub Wetland Freshwater Pond Lake Other Riverine May 15, 2024 0 0.1 0.20.05 mi 0 0.15 0.30.075 km 1:5,967 This page was produced by the NWI mapperNational Wetlands Inventory (NWI) This map is for general reference only. The US Fish and Wildlife Service is not responsible for the accuracy or currentness of the base data shown on this map. All wetlands related data should be used in accordance with the layer metadata found on the Wetlands Mapper web site. National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOODHAZARD AREAS Without Base Flood Elevation (BFE)Zone A, V, A99With BFE or DepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areasof 1% annual chance flood with averagedepth less than one foot or with drainageareas of less than one square mileZone X Future Conditions 1% Annual Chance Flood HazardZone X Area with Reduced Flood Risk due to Levee. See Notes.Zone X Area with Flood Risk due to LeveeZone D NO SCREENArea of Minimal Flood Hazard Zone X Area of Undetermined Flood HazardZone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below.The basemap shown complies with FEMA's basemapaccuracy standards The flood hazard information is derived directly from theauthoritative NFHL web services provided by FEMA. This mapwas exported on 5/13/2024 at 10:45 AM and does notreflect changes or amendments subsequent to this date andtime. The NFHL and effective information may change orbecome superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Legend OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 8 B 20.2 The pin displayed on the map is an approximatepoint selected by the user and does not representan authoritative property location. 1:6,000 77°54'31"W 34°9'19"N 77°53'54"W 34°8'49"N Basemap Imagery Source: USGS National Map 2023 17 Custom Soil Resource Report Map—Hydrologic Soil Group 37 8 2 6 0 0 37 8 2 6 4 0 37 8 2 6 8 0 37 8 2 7 2 0 37 8 2 7 6 0 37 8 2 8 0 0 37 8 2 8 4 0 37 8 2 8 8 0 37 8 2 9 2 0 37 8 2 6 0 0 37 8 2 6 4 0 37 8 2 6 8 0 37 8 2 7 2 0 37 8 2 7 6 0 37 8 2 8 0 0 37 8 2 8 4 0 37 8 2 8 8 0 232200 232240 232280 232320 232360 232400 232200 232240 232280 232320 232360 232400 34° 9' 10'' N 77 ° 5 4 ' 1 7 ' ' W 34° 9' 10'' N 77 ° 5 4 ' 7 ' ' W 34° 8' 59'' N 77 ° 5 4 ' 1 7 ' ' W 34° 8' 59'' N 77 ° 5 4 ' 7 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 18N WGS84 0 50 100 200 300 Feet 0 20 40 80 120 Meters Map Scale: 1:1,590 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Rating Polygons A A/D B B/D C C/D D Not rated or not available Soil Rating Lines A A/D B B/D C C/D D Not rated or not available Soil Rating Points A A/D B B/D C C/D D Not rated or not available Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: New Hanover County, North Carolina Survey Area Data: Version 25, Sep 13, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Nov 8, 2022—Dec 1, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Custom Soil Resource Report 18 Table—Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI Le Leon sand A/D 3.0 51.0% Ly Lynn Haven fine sand A/D 1.9 33.0% St Stallings fine sand A/D 0.9 15.9% Totals for Area of Interest 5.9 100.0% Rating Options—Hydrologic Soil Group Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher Custom Soil Resource Report 19 Sheetz – Shade Tree Lane Wilmington, NC Project Number: 64250.002 4 | www.timmons.com Peak Flow Analysis Worksheet – SCS Curve Numbers Hydraflow Report Project: Sheetz - Shade Tree Project No.: 64250.002 Calculated By: April Blye Date: 05/09/2024 SCS Weighted Curve Numbers - Pre-Development *CNi Ai (Ac)CNi x Ai 98 0.31 30 91 0.27 25 77 0.54 42 80 3.24 259 4.36 356 ∑ (Ci x Ai) ∑ Ai *CNi Ai (Ac)CNi x Ai 98 0.001 0 77 0.010 1 80 0.029 2 0.04 3 ∑ (Ci x Ai) ∑ Ai Cc = = 80 TIMMONS GROUP Category Impervious Lawns/Managed Open Space (D Soils) Gravel (D Soils) Woods (D Soils) DA 1.1 (To Analysis Point A) DA 1.2 (To Analysis Point B) Cc = = 82 Category Impervious Woods (D Soils) Lawns/Managed Open Space (D Soils) Project: Sheetz - Shade Tree Project No.: 64250.002 Calculated By: April Blye Date: 05/09/2024 SCS Weighted Curve Numbers - Post-Development *CNi Ai (Ac)CNi x Ai 98 1.84 180.3 80 0.12 9.6 1.96 190 ∑ (Ci x Ai) ∑ Ai *CNi Ai (Ac)CNi x Ai 98 0.16 16 80 2.19 175 2.35 191 ∑ (Ci x Ai) ∑ Ai *CNi Ai (Ac)CNi x Ai 98 0.01 1 80 0.07 5.6 77 0.01 0.8 0.09 7 ∑ (Ci x Ai) ∑ Ai Impervious TIMMONS GROUP DA 2.1 (TO BMP) Category Lawns/Managed Open Space (D Soils) Cc = = 97 DA 2.2 (Bypass to Analysis Point A) Category Impervious (Includes 0.1 ac future impervious) Cc = = 82 Lawns/Managed Open Space (D Soils) Cc = = 81 Lawns/Managed Open Space (D Soils) DA 2.3 (Bypass to Analysis Point B) Category Impervious Woods (D Soils) 1 2 4 6 7 8 9 1112 1 Watershed Model Schematic Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Project: 2024-05-15-Sheetz.gpw Wednesday, 05 / 15 / 2024 Hyd.Origin Description Legend 1 SCS Runoff DA1.1 (Analysis Pt A) 2 SCS Runoff DA1.2 (Analysis Pt B) 4 Combine Pre-Development Total 6 SCS Runoff DA2.1 (To SCM) 7 SCS Runoff DA2.2 (Bypass Analysis Pt A) 8 SCS Runoff DA2.3 (Bypass Analysis Pt B) 9 Reservoir UG DETENTION 11 Combine Post-Development (Undetained) 12 Combine Post-Development Total (Detained) Hydraflow Table of Contents 2024-05-15-Sheetz.gpw Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Watershed Model Schematic...................................................................................... 1 Hydrograph Return Period Recap............................................................................. 2 1 - Year Summary Report......................................................................................................................... 3 Hydrograph Reports................................................................................................................... 4 Hydrograph No. 1, SCS Runoff, DA1.1 (Analysis Pt A)............................................................ 4 TR-55 Tc Worksheet............................................................................................................ 5 Hydrograph No. 2, SCS Runoff, DA1.2 (Analysis Pt B)........................................................... 6 Hydrograph No. 4, Combine, Pre-Development Total.............................................................. 7 Hydrograph No. 6, SCS Runoff, DA2.1 (To SCM).................................................................... 8 Hydrograph No. 7, SCS Runoff, DA2.2 (Bypass Analysis Pt A)............................................... 9 TR-55 Tc Worksheet.......................................................................................................... 10 Hydrograph No. 8, SCS Runoff, DA2.3 (Bypass Analysis Pt B)............................................. 11 Hydrograph No. 9, Reservoir, UG DETENTION..................................................................... 12 Pond Report - UG DETENTION........................................................................................ 13 Hydrograph No. 11, Combine, Post-Development (Undetained)........................................... 14 Hydrograph No. 12, Combine, Post-Development Total (Detained)....................................... 15 2 - Year Summary Report....................................................................................................................... 16 Hydrograph Reports................................................................................................................. 17 Hydrograph No. 1, SCS Runoff, DA1.1 (Analysis Pt A).......................................................... 17 Hydrograph No. 2, SCS Runoff, DA1.2 (Analysis Pt B)......................................................... 18 Hydrograph No. 4, Combine, Pre-Development Total............................................................ 19 Hydrograph No. 6, SCS Runoff, DA2.1 (To SCM).................................................................. 20 Hydrograph No. 7, SCS Runoff, DA2.2 (Bypass Analysis Pt A)............................................. 21 Hydrograph No. 8, SCS Runoff, DA2.3 (Bypass Analysis Pt B)............................................. 22 Hydrograph No. 9, Reservoir, UG DETENTION..................................................................... 23 Hydrograph No. 11, Combine, Post-Development (Undetained)........................................... 24 Hydrograph No. 12, Combine, Post-Development Total (Detained)....................................... 25 10 - Year Summary Report....................................................................................................................... 26 Hydrograph Reports................................................................................................................. 27 Hydrograph No. 1, SCS Runoff, DA1.1 (Analysis Pt A).......................................................... 27 Hydrograph No. 2, SCS Runoff, DA1.2 (Analysis Pt B)......................................................... 28 Hydrograph No. 4, Combine, Pre-Development Total............................................................ 29 Hydrograph No. 6, SCS Runoff, DA2.1 (To SCM).................................................................. 30 Hydrograph No. 7, SCS Runoff, DA2.2 (Bypass Analysis Pt A)............................................. 31 Hydrograph No. 8, SCS Runoff, DA2.3 (Bypass Analysis Pt B)............................................. 32 Hydrograph No. 9, Reservoir, UG DETENTION..................................................................... 33 Hydrograph No. 11, Combine, Post-Development (Undetained)........................................... 34 Hydrograph No. 12, Combine, Post-Development Total (Detained)....................................... 35 25 - Year Summary Report....................................................................................................................... 36 Contents continued...2024-05-15-Sheetz.gpw Hydrograph Reports................................................................................................................. 37 Hydrograph No. 1, SCS Runoff, DA1.1 (Analysis Pt A).......................................................... 37 Hydrograph No. 2, SCS Runoff, DA1.2 (Analysis Pt B)......................................................... 38 Hydrograph No. 4, Combine, Pre-Development Total............................................................ 39 Hydrograph No. 6, SCS Runoff, DA2.1 (To SCM).................................................................. 40 Hydrograph No. 7, SCS Runoff, DA2.2 (Bypass Analysis Pt A)............................................. 41 Hydrograph No. 8, SCS Runoff, DA2.3 (Bypass Analysis Pt B)............................................. 42 Hydrograph No. 9, Reservoir, UG DETENTION..................................................................... 43 Hydrograph No. 11, Combine, Post-Development (Undetained)........................................... 44 Hydrograph No. 12, Combine, Post-Development Total (Detained)....................................... 45 100 - Year Summary Report....................................................................................................................... 46 Hydrograph Reports................................................................................................................. 47 Hydrograph No. 1, SCS Runoff, DA1.1 (Analysis Pt A).......................................................... 47 Hydrograph No. 2, SCS Runoff, DA1.2 (Analysis Pt B)......................................................... 48 Hydrograph No. 4, Combine, Pre-Development Total............................................................ 49 Hydrograph No. 6, SCS Runoff, DA2.1 (To SCM).................................................................. 50 Hydrograph No. 7, SCS Runoff, DA2.2 (Bypass Analysis Pt A)............................................. 51 Hydrograph No. 8, SCS Runoff, DA2.3 (Bypass Analysis Pt B)............................................. 52 Hydrograph No. 9, Reservoir, UG DETENTION..................................................................... 53 Hydrograph No. 11, Combine, Post-Development (Undetained)........................................... 54 Hydrograph No. 12, Combine, Post-Development Total (Detained)....................................... 55 IDF Report.................................................................................................................. 56 Hydrograph Return Period Recap 2 Hyd. Hydrograph Inflow Peak Outflow (cfs) Hydrograph No. type hyd(s) Description (origin) 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr 1 SCS Runoff ------ 7.710 10.31 ------- ------- 18.76 24.89 ------- 36.59 DA1.1 (Analysis Pt A) 2 SCS Runoff ------ 0.091 0.123 ------- ------- 0.228 0.305 ------- 0.451 DA1.2 (Analysis Pt B) 4 Combine 1, 2, 7.751 10.37 ------- ------- 18.86 25.03 ------- 36.80 Pre-Development Total 6 SCS Runoff ------ 7.183 8.764 ------- ------- 13.71 17.28 ------- 24.12 DA2.1 (To SCM) 7 SCS Runoff ------ 3.998 5.386 ------- ------- 9.921 13.23 ------- 19.55 DA2.2 (Bypass Analysis Pt A) 8 SCS Runoff ------ 0.221 0.295 ------- ------- 0.532 0.704 ------- 1.032 DA2.3 (Bypass Analysis Pt B) 9 Reservoir 6 2.204 4.200 ------- ------- 8.011 10.39 ------- 15.76 UG DETENTION 11 Combine 6, 7, 8, 10.09 12.76 ------- ------- 21.29 27.49 ------- 39.38 Post-Development (Undetained) 12 Combine 7, 8, 9, 5.900 9.724 ------- ------- 18.02 23.63 ------- 35.13 Post-Development Total (Detained) Proj. file: 2024-05-15-Sheetz.gpw Wednesday, 05 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hydrograph Summary Report 3 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 7.710 2 734 34,056 ------ ------ ------ DA1.1 (Analysis Pt A) 2 SCS Runoff 0.091 2 724 271 ------ ------ ------ DA1.2 (Analysis Pt B) 4 Combine 7.751 2 734 34,327 1, 2, ------ ------ Pre-Development Total 6 SCS Runoff 7.183 2 724 23,957 ------ ------ ------ DA2.1 (To SCM) 7 SCS Runoff 3.998 2 734 17,668 ------ ------ ------ DA2.2 (Bypass Analysis Pt A) 8 SCS Runoff 0.221 2 724 659 ------ ------ ------ DA2.3 (Bypass Analysis Pt B) 9 Reservoir 2.204 2 740 23,937 6 13.99 11,784 UG DETENTION 11 Combine 10.09 2 724 42,284 6, 7, 8, ------ ------ Post-Development (Undetained) 12 Combine 5.900 2 738 42,264 7, 8, 9, ------ ------ Post-Development Total (Detained) 2024-05-15-Sheetz.gpw Return Period: 1 Year Wednesday, 05 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 1 DA1.1 (Analysis Pt A) Hydrograph type = SCS Runoff Peak discharge = 7.710 cfs Storm frequency = 1 yrs Time to peak = 734 min Time interval = 2 min Hyd. volume = 34,056 cuft Drainage area = 4.360 ac Curve number = 82 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 19.60 min Total precip. = 3.94 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 4 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 Q (cfs) Time (min) DA1.1 (Analysis Pt A) Hyd. No. 1 -- 1 Year Hyd No. 1 TR55 Tc Worksheet 5 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hyd. No. 1 DA1.1 (Analysis Pt A) Description A B C Totals Sheet Flow Manning's n-value = 0.150 0.011 0.011 Flow length (ft) = 50.0 0.0 0.0 Two-year 24-hr precip. (in) = 4.78 0.00 0.00 Land slope (%) = 1.00 0.00 0.00 Travel Time (min) = 6.08 + 0.00 + 0.00 = 6.08 Shallow Concentrated Flow Flow length (ft) = 55.00 0.00 0.00 Watercourse slope (%) = 5.10 0.00 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =3.64 0.00 0.00 Travel Time (min) = 0.25 + 0.00 + 0.00 = 0.25 Channel Flow X sectional flow area (sqft) = 21.00 7.00 12.56 Wetted perimeter (ft) = 15.23 9.40 12.56 Channel slope (%) = 0.60 2.60 0.10 Manning's n-value = 0.150 0.013 0.013 Velocity (ft/s) =0.95 15.17 3.62 Flow length (ft) ({0})624.0 42.0 503.0 Travel Time (min) = 10.90 + 0.05 + 2.31 = 13.26 Total Travel Time, Tc .............................................................................. 19.60 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 2 DA1.2 (Analysis Pt B) Hydrograph type = SCS Runoff Peak discharge = 0.091 cfs Storm frequency = 1 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 271 cuft Drainage area = 0.040 ac Curve number = 80 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 3.94 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 6 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 0.01 0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05 0.06 0.06 0.07 0.07 0.08 0.08 0.09 0.09 0.10 0.10 Q (cfs) Time (min) DA1.2 (Analysis Pt B) Hyd. No. 2 -- 1 Year Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 4 Pre-Development Total Hydrograph type = Combine Peak discharge = 7.751 cfs Storm frequency = 1 yrs Time to peak = 734 min Time interval = 2 min Hyd. volume = 34,327 cuft Inflow hyds. = 1, 2 Contrib. drain. area = 4.400 ac 7 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 Q (cfs) Time (min) Pre-Development Total Hyd. No. 4 -- 1 Year Hyd No. 4 Hyd No. 1 Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 6 DA2.1 (To SCM) Hydrograph type = SCS Runoff Peak discharge = 7.183 cfs Storm frequency = 1 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 23,957 cuft Drainage area = 1.960 ac Curve number = 97 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 3.94 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 8 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 Q (cfs) Time (min) DA2.1 (To SCM) Hyd. No. 6 -- 1 Year Hyd No. 6 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 7 DA2.2 (Bypass Analysis Pt A) Hydrograph type = SCS Runoff Peak discharge = 3.998 cfs Storm frequency = 1 yrs Time to peak = 734 min Time interval = 2 min Hyd. volume = 17,668 cuft Drainage area = 2.350 ac Curve number = 81 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 19.60 min Total precip. = 3.94 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 9 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 Q (cfs) Time (min) DA2.2 (Bypass Analysis Pt A) Hyd. No. 7 -- 1 Year Hyd No. 7 TR55 Tc Worksheet 10 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hyd. No. 7 DA2.2 (Bypass Analysis Pt A) Description A B C Totals Sheet Flow Manning's n-value = 0.150 0.011 0.011 Flow length (ft) = 50.0 0.0 0.0 Two-year 24-hr precip. (in) = 4.78 0.00 0.00 Land slope (%) = 1.00 0.00 0.00 Travel Time (min) = 6.08 + 0.00 + 0.00 = 6.08 Shallow Concentrated Flow Flow length (ft) = 55.00 0.00 0.00 Watercourse slope (%) = 5.10 0.00 0.00 Surface description = Unpaved Paved Paved Average velocity (ft/s) =3.64 0.00 0.00 Travel Time (min) = 0.25 + 0.00 + 0.00 = 0.25 Channel Flow X sectional flow area (sqft) = 21.00 7.00 12.56 Wetted perimeter (ft) = 15.23 9.40 12.56 Channel slope (%) = 0.60 2.60 0.10 Manning's n-value = 0.150 0.013 0.013 Velocity (ft/s) =0.95 15.17 3.62 Flow length (ft) ({0})624.0 42.0 503.0 Travel Time (min) = 10.90 + 0.05 + 2.31 = 13.26 Total Travel Time, Tc .............................................................................. 19.60 min Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 8 DA2.3 (Bypass Analysis Pt B) Hydrograph type = SCS Runoff Peak discharge = 0.221 cfs Storm frequency = 1 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 659 cuft Drainage area = 0.090 ac Curve number = 82 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 3.94 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 11 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) DA2.3 (Bypass Analysis Pt B) Hyd. No. 8 -- 1 Year Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 9 UG DETENTION Hydrograph type = Reservoir Peak discharge = 2.204 cfs Storm frequency = 1 yrs Time to peak = 740 min Time interval = 2 min Hyd. volume = 23,937 cuft Inflow hyd. No. = 6 - DA2.1 (To SCM) Max. Elevation = 13.99 ft Reservoir name = UG DETENTION Max. Storage = 11,784 cuft Storage Indication method used. 12 0 240 480 720 960 1200 1440 1680 1920 2160 2400 2640 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 Q (cfs) Time (min) UG DETENTION Hyd. No. 9 -- 1 Year Hyd No. 9 Hyd No. 6 Total storage used = 11,784 cuft Pond Report 13 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Pond No. 1 - UG DETENTION Pond Data UG Chambers -Invert elev. = 11.00 ft, Rise x Span = 6.00 x 6.00 ft, Barrel Len = 836.00 ft, No. Barrels = 1, Slope = 0.00%, Headers = No Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) 0.00 11.00 n/a 0 0 0.60 11.60 n/a 1,230 1,230 1.20 12.20 n/a 2,138 3,368 1.80 12.80 n/a 2,600 5,968 2.40 13.40 n/a 2,864 8,832 3.00 14.00 n/a 2,992 11,824 3.60 14.60 n/a 2,992 14,816 4.20 15.20 n/a 2,863 17,679 4.80 15.80 n/a 2,599 20,277 5.40 16.40 n/a 2,136 22,413 6.00 17.00 n/a 1,229 23,642 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in)= 24.00 2.08 10.00 0.00 Span (in)= 24.00 2.08 18.00 0.00 No. Barrels = 1 1 1 0 Invert El. (ft)= 10.50 11.00 13.10 0.00 Length (ft)= 50.00 1.00 0.50 0.00 Slope (%)= 0.50 1.00 1.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff.= 0.60 0.60 0.60 0.60 Multi-Stage = n/a Yes No No Crest Len (ft)= 3.47 1.00 0.00 0.00 Crest El. (ft)= 16.00 14.50 0.00 0.00 Weir Coeff.= 3.33 3.33 3.33 3.33 Weir Type = Rect Rect --- --- Multi-Stage = Yes Yes No No Exfil.(in/hr)= 0.000 (by Wet area) TW Elev. (ft)= 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). 0.00 4.00 8.00 12.00 16.00 20.00 24.00 28.00 32.00 36.00 40.00 Stage (ft) 0.00 11.00 1.00 12.00 2.00 13.00 3.00 14.00 4.00 15.00 5.00 16.00 6.00 17.00 Elev (ft) Discharge (cfs) Stage / Discharge Total Q Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 11 Post-Development (Undetained) Hydrograph type = Combine Peak discharge = 10.09 cfs Storm frequency = 1 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 42,284 cuft Inflow hyds. = 6, 7, 8 Contrib. drain. area = 4.400 ac 14 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 Q (cfs) Time (min) Post-Development (Undetained) Hyd. No. 11 -- 1 Year Hyd No. 11 Hyd No. 6 Hyd No. 7 Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 12 Post-Development Total (Detained) Hydrograph type = Combine Peak discharge = 5.900 cfs Storm frequency = 1 yrs Time to peak = 738 min Time interval = 2 min Hyd. volume = 42,264 cuft Inflow hyds. = 7, 8, 9 Contrib. drain. area = 2.440 ac 15 0 240 480 720 960 1200 1440 1680 1920 2160 2400 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 5.00 5.00 6.00 6.00 Q (cfs) Time (min) Post-Development Total (Detained) Hyd. No. 12 -- 1 Year Hyd No. 12 Hyd No. 7 Hyd No. 8 Hyd No. 9 Hydrograph Summary Report 16 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 10.31 2 732 45,630 ------ ------ ------ DA1.1 (Analysis Pt A) 2 SCS Runoff 0.123 2 724 368 ------ ------ ------ DA1.2 (Analysis Pt B) 4 Combine 10.37 2 732 45,998 1, 2, ------ ------ Pre-Development Total 6 SCS Runoff 8.764 2 724 29,535 ------ ------ ------ DA2.1 (To SCM) 7 SCS Runoff 5.386 2 734 23,815 ------ ------ ------ DA2.2 (Bypass Analysis Pt A) 8 SCS Runoff 0.295 2 724 883 ------ ------ ------ DA2.3 (Bypass Analysis Pt B) 9 Reservoir 4.200 2 732 29,515 6 14.17 12,670 UG DETENTION 11 Combine 12.76 2 724 54,233 6, 7, 8, ------ ------ Post-Development (Undetained) 12 Combine 9.724 2 732 54,213 7, 8, 9, ------ ------ Post-Development Total (Detained) 2024-05-15-Sheetz.gpw Return Period: 2 Year Wednesday, 05 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 1 DA1.1 (Analysis Pt A) Hydrograph type = SCS Runoff Peak discharge = 10.31 cfs Storm frequency = 2 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 45,630 cuft Drainage area = 4.360 ac Curve number = 82 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 19.60 min Total precip. = 4.78 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 17 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 Q (cfs) Time (min) DA1.1 (Analysis Pt A) Hyd. No. 1 -- 2 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 2 DA1.2 (Analysis Pt B) Hydrograph type = SCS Runoff Peak discharge = 0.123 cfs Storm frequency = 2 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 368 cuft Drainage area = 0.040 ac Curve number = 80 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 4.78 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 18 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) DA1.2 (Analysis Pt B) Hyd. No. 2 -- 2 Year Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 4 Pre-Development Total Hydrograph type = Combine Peak discharge = 10.37 cfs Storm frequency = 2 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 45,998 cuft Inflow hyds. = 1, 2 Contrib. drain. area = 4.400 ac 19 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 Q (cfs) Time (min) Pre-Development Total Hyd. No. 4 -- 2 Year Hyd No. 4 Hyd No. 1 Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 6 DA2.1 (To SCM) Hydrograph type = SCS Runoff Peak discharge = 8.764 cfs Storm frequency = 2 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 29,535 cuft Drainage area = 1.960 ac Curve number = 97 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 4.78 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 20 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (min) DA2.1 (To SCM) Hyd. No. 6 -- 2 Year Hyd No. 6 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 7 DA2.2 (Bypass Analysis Pt A) Hydrograph type = SCS Runoff Peak discharge = 5.386 cfs Storm frequency = 2 yrs Time to peak = 734 min Time interval = 2 min Hyd. volume = 23,815 cuft Drainage area = 2.350 ac Curve number = 81 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 19.60 min Total precip. = 4.78 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 21 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 3.00 3.00 4.00 4.00 5.00 5.00 6.00 6.00 Q (cfs) Time (min) DA2.2 (Bypass Analysis Pt A) Hyd. No. 7 -- 2 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 8 DA2.3 (Bypass Analysis Pt B) Hydrograph type = SCS Runoff Peak discharge = 0.295 cfs Storm frequency = 2 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 883 cuft Drainage area = 0.090 ac Curve number = 82 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 4.78 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 22 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) DA2.3 (Bypass Analysis Pt B) Hyd. No. 8 -- 2 Year Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 9 UG DETENTION Hydrograph type = Reservoir Peak discharge = 4.200 cfs Storm frequency = 2 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 29,515 cuft Inflow hyd. No. = 6 - DA2.1 (To SCM) Max. Elevation = 14.17 ft Reservoir name = UG DETENTION Max. Storage = 12,670 cuft Storage Indication method used. 23 0 240 480 720 960 1200 1440 1680 1920 2160 2400 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (min) UG DETENTION Hyd. No. 9 -- 2 Year Hyd No. 9 Hyd No. 6 Total storage used = 12,670 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 11 Post-Development (Undetained) Hydrograph type = Combine Peak discharge = 12.76 cfs Storm frequency = 2 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 54,233 cuft Inflow hyds. = 6, 7, 8 Contrib. drain. area = 4.400 ac 24 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 14.00 14.00 Q (cfs) Time (min) Post-Development (Undetained) Hyd. No. 11 -- 2 Year Hyd No. 11 Hyd No. 6 Hyd No. 7 Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 12 Post-Development Total (Detained) Hydrograph type = Combine Peak discharge = 9.724 cfs Storm frequency = 2 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 54,213 cuft Inflow hyds. = 7, 8, 9 Contrib. drain. area = 2.440 ac 25 0 240 480 720 960 1200 1440 1680 1920 2160 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (min) Post-Development Total (Detained) Hyd. No. 12 -- 2 Year Hyd No. 12 Hyd No. 7 Hyd No. 8 Hyd No. 9 Hydrograph Summary Report 26 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 18.76 2 732 84,056 ------ ------ ------ DA1.1 (Analysis Pt A) 2 SCS Runoff 0.228 2 724 692 ------ ------ ------ DA1.2 (Analysis Pt B) 4 Combine 18.86 2 732 84,748 1, 2, ------ ------ Pre-Development Total 6 SCS Runoff 13.71 2 724 47,100 ------ ------ ------ DA2.1 (To SCM) 7 SCS Runoff 9.921 2 732 44,333 ------ ------ ------ DA2.2 (Bypass Analysis Pt A) 8 SCS Runoff 0.532 2 724 1,627 ------ ------ ------ DA2.3 (Bypass Analysis Pt B) 9 Reservoir 8.011 2 730 47,080 6 14.88 16,136 UG DETENTION 11 Combine 21.29 2 724 93,060 6, 7, 8, ------ ------ Post-Development (Undetained) 12 Combine 18.02 2 732 93,040 7, 8, 9, ------ ------ Post-Development Total (Detained) 2024-05-15-Sheetz.gpw Return Period: 10 Year Wednesday, 05 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 1 DA1.1 (Analysis Pt A) Hydrograph type = SCS Runoff Peak discharge = 18.76 cfs Storm frequency = 10 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 84,056 cuft Drainage area = 4.360 ac Curve number = 82 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 19.60 min Total precip. = 7.42 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 27 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 3.00 3.00 6.00 6.00 9.00 9.00 12.00 12.00 15.00 15.00 18.00 18.00 21.00 21.00 Q (cfs) Time (min) DA1.1 (Analysis Pt A) Hyd. No. 1 -- 10 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 2 DA1.2 (Analysis Pt B) Hydrograph type = SCS Runoff Peak discharge = 0.228 cfs Storm frequency = 10 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 692 cuft Drainage area = 0.040 ac Curve number = 80 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 7.42 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 28 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) DA1.2 (Analysis Pt B) Hyd. No. 2 -- 10 Year Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 4 Pre-Development Total Hydrograph type = Combine Peak discharge = 18.86 cfs Storm frequency = 10 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 84,748 cuft Inflow hyds. = 1, 2 Contrib. drain. area = 4.400 ac 29 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 3.00 3.00 6.00 6.00 9.00 9.00 12.00 12.00 15.00 15.00 18.00 18.00 21.00 21.00 Q (cfs) Time (min) Pre-Development Total Hyd. No. 4 -- 10 Year Hyd No. 4 Hyd No. 1 Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 6 DA2.1 (To SCM) Hydrograph type = SCS Runoff Peak discharge = 13.71 cfs Storm frequency = 10 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 47,100 cuft Drainage area = 1.960 ac Curve number = 97 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 7.42 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 30 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 14.00 14.00 Q (cfs) Time (min) DA2.1 (To SCM) Hyd. No. 6 -- 10 Year Hyd No. 6 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 7 DA2.2 (Bypass Analysis Pt A) Hydrograph type = SCS Runoff Peak discharge = 9.921 cfs Storm frequency = 10 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 44,333 cuft Drainage area = 2.350 ac Curve number = 81 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 19.60 min Total precip. = 7.42 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 31 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 Q (cfs) Time (min) DA2.2 (Bypass Analysis Pt A) Hyd. No. 7 -- 10 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 8 DA2.3 (Bypass Analysis Pt B) Hydrograph type = SCS Runoff Peak discharge = 0.532 cfs Storm frequency = 10 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 1,627 cuft Drainage area = 0.090 ac Curve number = 82 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 7.42 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 32 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) DA2.3 (Bypass Analysis Pt B) Hyd. No. 8 -- 10 Year Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 9 UG DETENTION Hydrograph type = Reservoir Peak discharge = 8.011 cfs Storm frequency = 10 yrs Time to peak = 730 min Time interval = 2 min Hyd. volume = 47,080 cuft Inflow hyd. No. = 6 - DA2.1 (To SCM) Max. Elevation = 14.88 ft Reservoir name = UG DETENTION Max. Storage = 16,136 cuft Storage Indication method used. 33 0 240 480 720 960 1200 1440 1680 1920 2160 2400 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 14.00 14.00 Q (cfs) Time (min) UG DETENTION Hyd. No. 9 -- 10 Year Hyd No. 9 Hyd No. 6 Total storage used = 16,136 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 11 Post-Development (Undetained) Hydrograph type = Combine Peak discharge = 21.29 cfs Storm frequency = 10 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 93,060 cuft Inflow hyds. = 6, 7, 8 Contrib. drain. area = 4.400 ac 34 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 Q (cfs) Time (min) Post-Development (Undetained) Hyd. No. 11 -- 10 Year Hyd No. 11 Hyd No. 6 Hyd No. 7 Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 12 Post-Development Total (Detained) Hydrograph type = Combine Peak discharge = 18.02 cfs Storm frequency = 10 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 93,040 cuft Inflow hyds. = 7, 8, 9 Contrib. drain. area = 2.440 ac 35 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 3.00 3.00 6.00 6.00 9.00 9.00 12.00 12.00 15.00 15.00 18.00 18.00 21.00 21.00 Q (cfs) Time (min) Post-Development Total (Detained) Hyd. No. 12 -- 10 Year Hyd No. 12 Hyd No. 7 Hyd No. 8 Hyd No. 9 Hydrograph Summary Report 36 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 24.89 2 732 112,853 ------ ------ ------ DA1.1 (Analysis Pt A) 2 SCS Runoff 0.305 2 724 937 ------ ------ ------ DA1.2 (Analysis Pt B) 4 Combine 25.03 2 732 113,790 1, 2, ------ ------ Pre-Development Total 6 SCS Runoff 17.28 2 724 59,823 ------ ------ ------ DA2.1 (To SCM) 7 SCS Runoff 13.23 2 732 59,766 ------ ------ ------ DA2.2 (Bypass Analysis Pt A) 8 SCS Runoff 0.704 2 724 2,184 ------ ------ ------ DA2.3 (Bypass Analysis Pt B) 9 Reservoir 10.39 2 730 59,803 6 15.26 17,938 UG DETENTION 11 Combine 27.49 2 724 121,773 6, 7, 8, ------ ------ Post-Development (Undetained) 12 Combine 23.63 2 732 121,754 7, 8, 9, ------ ------ Post-Development Total (Detained) 2024-05-15-Sheetz.gpw Return Period: 25 Year Wednesday, 05 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 1 DA1.1 (Analysis Pt A) Hydrograph type = SCS Runoff Peak discharge = 24.89 cfs Storm frequency = 25 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 112,853 cuft Drainage area = 4.360 ac Curve number = 82 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 19.60 min Total precip. = 9.33 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 37 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 28.00 28.00 Q (cfs) Time (min) DA1.1 (Analysis Pt A) Hyd. No. 1 -- 25 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 2 DA1.2 (Analysis Pt B) Hydrograph type = SCS Runoff Peak discharge = 0.305 cfs Storm frequency = 25 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 937 cuft Drainage area = 0.040 ac Curve number = 80 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 9.33 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 38 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) DA1.2 (Analysis Pt B) Hyd. No. 2 -- 25 Year Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 4 Pre-Development Total Hydrograph type = Combine Peak discharge = 25.03 cfs Storm frequency = 25 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 113,790 cuft Inflow hyds. = 1, 2 Contrib. drain. area = 4.400 ac 39 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 28.00 28.00 Q (cfs) Time (min) Pre-Development Total Hyd. No. 4 -- 25 Year Hyd No. 4 Hyd No. 1 Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 6 DA2.1 (To SCM) Hydrograph type = SCS Runoff Peak discharge = 17.28 cfs Storm frequency = 25 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 59,823 cuft Drainage area = 1.960 ac Curve number = 97 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 9.33 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 40 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Q (cfs) 0.00 0.00 3.00 3.00 6.00 6.00 9.00 9.00 12.00 12.00 15.00 15.00 18.00 18.00 Q (cfs) Time (min) DA2.1 (To SCM) Hyd. No. 6 -- 25 Year Hyd No. 6 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 7 DA2.2 (Bypass Analysis Pt A) Hydrograph type = SCS Runoff Peak discharge = 13.23 cfs Storm frequency = 25 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 59,766 cuft Drainage area = 2.350 ac Curve number = 81 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 19.60 min Total precip. = 9.33 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 41 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 2.00 2.00 4.00 4.00 6.00 6.00 8.00 8.00 10.00 10.00 12.00 12.00 14.00 14.00 Q (cfs) Time (min) DA2.2 (Bypass Analysis Pt A) Hyd. No. 7 -- 25 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 8 DA2.3 (Bypass Analysis Pt B) Hydrograph type = SCS Runoff Peak discharge = 0.704 cfs Storm frequency = 25 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 2,184 cuft Drainage area = 0.090 ac Curve number = 82 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 9.33 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 42 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Q (cfs) 0.00 0.00 0.10 0.10 0.20 0.20 0.30 0.30 0.40 0.40 0.50 0.50 0.60 0.60 0.70 0.70 0.80 0.80 0.90 0.90 1.00 1.00 Q (cfs) Time (min) DA2.3 (Bypass Analysis Pt B) Hyd. No. 8 -- 25 Year Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 9 UG DETENTION Hydrograph type = Reservoir Peak discharge = 10.39 cfs Storm frequency = 25 yrs Time to peak = 730 min Time interval = 2 min Hyd. volume = 59,803 cuft Inflow hyd. No. = 6 - DA2.1 (To SCM) Max. Elevation = 15.26 ft Reservoir name = UG DETENTION Max. Storage = 17,938 cuft Storage Indication method used. 43 0 240 480 720 960 1200 1440 1680 1920 2160 Q (cfs) 0.00 0.00 3.00 3.00 6.00 6.00 9.00 9.00 12.00 12.00 15.00 15.00 18.00 18.00 Q (cfs) Time (min) UG DETENTION Hyd. No. 9 -- 25 Year Hyd No. 9 Hyd No. 6 Total storage used = 17,938 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 11 Post-Development (Undetained) Hydrograph type = Combine Peak discharge = 27.49 cfs Storm frequency = 25 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 121,773 cuft Inflow hyds. = 6, 7, 8 Contrib. drain. area = 4.400 ac 44 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 28.00 28.00 Q (cfs) Time (min) Post-Development (Undetained) Hyd. No. 11 -- 25 Year Hyd No. 11 Hyd No. 6 Hyd No. 7 Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 12 Post-Development Total (Detained) Hydrograph type = Combine Peak discharge = 23.63 cfs Storm frequency = 25 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 121,754 cuft Inflow hyds. = 7, 8, 9 Contrib. drain. area = 2.440 ac 45 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 Q (cfs) Time (min) Post-Development Total (Detained) Hyd. No. 12 -- 25 Year Hyd No. 12 Hyd No. 7 Hyd No. 8 Hyd No. 9 Hydrograph Summary Report 46 Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph No. type flow interval Peak volume hyd(s) elevation strge used Description (origin) (cfs) (min) (min) (cuft) (ft) (cuft) 1 SCS Runoff 36.59 2 732 169,227 ------ ------ ------ DA1.1 (Analysis Pt A) 2 SCS Runoff 0.451 2 724 1,418 ------ ------ ------ DA1.2 (Analysis Pt B) 4 Combine 36.80 2 732 170,644 1, 2, ------ ------ Pre-Development Total 6 SCS Runoff 24.12 2 724 84,284 ------ ------ ------ DA2.1 (To SCM) 7 SCS Runoff 19.55 2 732 90,040 ------ ------ ------ DA2.2 (Bypass Analysis Pt A) 8 SCS Runoff 1.032 2 724 3,275 ------ ------ ------ DA2.3 (Bypass Analysis Pt B) 9 Reservoir 15.76 2 728 84,264 6 15.99 20,947 UG DETENTION 11 Combine 39.38 2 724 177,599 6, 7, 8, ------ ------ Post-Development (Undetained) 12 Combine 35.13 2 730 177,579 7, 8, 9, ------ ------ Post-Development Total (Detained) 2024-05-15-Sheetz.gpw Return Period: 100 Year Wednesday, 05 / 15 / 2024 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 1 DA1.1 (Analysis Pt A) Hydrograph type = SCS Runoff Peak discharge = 36.59 cfs Storm frequency = 100 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 169,227 cuft Drainage area = 4.360 ac Curve number = 82 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 19.60 min Total precip. = 13.00 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 47 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 Q (cfs) Time (min) DA1.1 (Analysis Pt A) Hyd. No. 1 -- 100 Year Hyd No. 1 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 2 DA1.2 (Analysis Pt B) Hydrograph type = SCS Runoff Peak discharge = 0.451 cfs Storm frequency = 100 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 1,418 cuft Drainage area = 0.040 ac Curve number = 80 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 13.00 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 48 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Q (cfs) 0.00 0.00 0.05 0.05 0.10 0.10 0.15 0.15 0.20 0.20 0.25 0.25 0.30 0.30 0.35 0.35 0.40 0.40 0.45 0.45 0.50 0.50 Q (cfs) Time (min) DA1.2 (Analysis Pt B) Hyd. No. 2 -- 100 Year Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 4 Pre-Development Total Hydrograph type = Combine Peak discharge = 36.80 cfs Storm frequency = 100 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 170,644 cuft Inflow hyds. = 1, 2 Contrib. drain. area = 4.400 ac 49 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 Q (cfs) Time (min) Pre-Development Total Hyd. No. 4 -- 100 Year Hyd No. 4 Hyd No. 1 Hyd No. 2 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 6 DA2.1 (To SCM) Hydrograph type = SCS Runoff Peak discharge = 24.12 cfs Storm frequency = 100 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 84,284 cuft Drainage area = 1.960 ac Curve number = 97 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 13.00 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 50 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 28.00 28.00 Q (cfs) Time (min) DA2.1 (To SCM) Hyd. No. 6 -- 100 Year Hyd No. 6 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 7 DA2.2 (Bypass Analysis Pt A) Hydrograph type = SCS Runoff Peak discharge = 19.55 cfs Storm frequency = 100 yrs Time to peak = 732 min Time interval = 2 min Hyd. volume = 90,040 cuft Drainage area = 2.350 ac Curve number = 81 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = TR55 Time of conc. (Tc) = 19.60 min Total precip. = 13.00 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 51 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 3.00 3.00 6.00 6.00 9.00 9.00 12.00 12.00 15.00 15.00 18.00 18.00 21.00 21.00 Q (cfs) Time (min) DA2.2 (Bypass Analysis Pt A) Hyd. No. 7 -- 100 Year Hyd No. 7 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 8 DA2.3 (Bypass Analysis Pt B) Hydrograph type = SCS Runoff Peak discharge = 1.032 cfs Storm frequency = 100 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 3,275 cuft Drainage area = 0.090 ac Curve number = 82 Basin Slope = 0.0 % Hydraulic length = 0 ft Tc method = User Time of conc. (Tc) = 5.00 min Total precip. = 13.00 in Distribution = Type III Storm duration = 24 hrs Shape factor = 484 52 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 Q (cfs) 0.00 0.00 1.00 1.00 2.00 2.00 Q (cfs) Time (min) DA2.3 (Bypass Analysis Pt B) Hyd. No. 8 -- 100 Year Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 9 UG DETENTION Hydrograph type = Reservoir Peak discharge = 15.76 cfs Storm frequency = 100 yrs Time to peak = 728 min Time interval = 2 min Hyd. volume = 84,264 cuft Inflow hyd. No. = 6 - DA2.1 (To SCM) Max. Elevation = 15.99 ft Reservoir name = UG DETENTION Max. Storage = 20,947 cuft Storage Indication method used. 53 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 4.00 4.00 8.00 8.00 12.00 12.00 16.00 16.00 20.00 20.00 24.00 24.00 28.00 28.00 Q (cfs) Time (min) UG DETENTION Hyd. No. 9 -- 100 Year Hyd No. 9 Hyd No. 6 Total storage used = 20,947 cuft Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 11 Post-Development (Undetained) Hydrograph type = Combine Peak discharge = 39.38 cfs Storm frequency = 100 yrs Time to peak = 724 min Time interval = 2 min Hyd. volume = 177,599 cuft Inflow hyds. = 6, 7, 8 Contrib. drain. area = 4.400 ac 54 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 Q (cfs) Time (min) Post-Development (Undetained) Hyd. No. 11 -- 100 Year Hyd No. 11 Hyd No. 6 Hyd No. 7 Hyd No. 8 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Hyd. No. 12 Post-Development Total (Detained) Hydrograph type = Combine Peak discharge = 35.13 cfs Storm frequency = 100 yrs Time to peak = 730 min Time interval = 2 min Hyd. volume = 177,579 cuft Inflow hyds. = 7, 8, 9 Contrib. drain. area = 2.440 ac 55 0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560 Q (cfs) 0.00 0.00 10.00 10.00 20.00 20.00 30.00 30.00 40.00 40.00 Q (cfs) Time (min) Post-Development Total (Detained) Hyd. No. 12 -- 100 Year Hyd No. 12 Hyd No. 7 Hyd No. 8 Hyd No. 9 Hydraflow Rainfall Report 56 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Wednesday, 05 / 15 / 2024 Return Intensity-Duration-Frequency Equation Coefficients (FHA) Period (Yrs) B D E (N/A) 1 78.7228 12.4000 0.8810 -------- 2 91.8716 12.6000 0.8709 -------- 3 0.0000 0.0000 0.0000 -------- 5 97.1683 12.7000 0.8342 -------- 10 93.7879 12.1000 0.7948 -------- 25 87.4911 11.1000 0.7431 -------- 50 82.4765 10.5000 0.7036 -------- 100 74.7156 9.3000 0.6577 -------- File name: WILMINGTON.IDF Intensity = B / (Tc + D)^E Return Intensity Values (in/hr) Period (Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60 1 6.36 5.09 4.26 3.68 3.24 2.90 2.63 2.41 2.22 2.06 1.93 1.81 2 7.56 6.08 5.11 4.42 3.90 3.50 3.18 2.91 2.69 2.50 2.34 2.20 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5 8.84 7.18 6.08 5.30 4.70 4.24 3.87 3.56 3.30 3.08 2.89 2.72 10 9.82 8.01 6.81 5.95 5.31 4.80 4.39 4.05 3.77 3.52 3.31 3.13 25 11.10 9.08 7.75 6.80 6.09 5.53 5.08 4.70 4.39 4.12 3.88 3.68 50 11.99 9.85 8.45 7.45 6.69 6.10 5.62 5.22 4.89 4.60 4.35 4.13 100 12.99 10.66 9.16 8.10 7.31 6.68 6.17 5.75 5.40 5.10 4.83 4.60 Tc = time in minutes. Values may exceed 60. Rainfall Precipitation Table (in) Precip. file name: S:\332\64250-Sheetz\002-332-ShadeTreeLn\Calc\Storm\02_Hydraflow\2_Hydraflow SCM\Wilmington.pcp Storm Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr SCS 24-hour 3.94 4.78 0.00 3.30 7.42 9.33 6.80 13.00 SCS 6-Hr 0.00 1.80 0.00 0.00 2.60 0.00 0.00 4.00 Huff-1st 0.00 1.55 0.00 2.75 4.00 5.38 6.50 8.00 Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Custom 0.00 1.75 0.00 2.80 3.90 5.25 6.00 7.10 Sheetz – Shade Tree Lane Wilmington, NC Project Number: 64250.002 5 | www.timmons.com Water Quality Calculations Contech Design Worksheets Design Engineer:lrs Blue Cells =Input Date 5/14/2024 Black Cells =Calculation Site Information Project Name Sheetz - Shade Tree Lane REV2 Project State NC Project Location Wilmington SE Drainage Area, Ad 1.96 ac Impervious Area, Ai 1.84 ac Pervious Area, Ap 0.12 % Impervious 94% Runoff Coefficient, Rv 0.89 =0.05+0.9*(Ai/Ad) Water Quality Volume Calculations Design storm rainfall depth, Rd 1.5 in Water quality volume, WQV 9550.5 ft3 =Ad*Rv*Rd*(43560/12) Storage Component Calculations Capture 75% of WQV 7162.9 ft3 =0.75*WQV Pretreatment credit (estimated or calculated), %pre 30% Mass loading calculations Mean Annual Rainfall, P 58 in Agency required % removal 85% Percent Runoff Capture (% capture)90% Mean Annual Runoff,Vt 334,364 ft3 =P*Ad*Rv*(43560/12)*%capture Event Mean Concentration of Pollutant, EMC 70.0 mg/l (Suggestion: Use 60 for residential, 70 for Commercial, 100 for Industrial) Annual Mass Load, Mtotal 1460.27 lbs =EMC*Vt*(28.3)*(0.000001)*(2.2046) Filter System Filtration brand StormFilter Cartridge height 18 in Cartridge Quantity Calculation Mass removed by pretreatment system, Mpre 438 lbs =Mtotal * %removal Mass load to filters after pretreatment, Mpass1 1022 lbs =Mtotal - Mpre Estimate the required filter efficiency, Efilter 79%=1+(%removal - 1)/(1 - %pre) Mass to be captured by filters, Mfilter 803 lbs =Mpass1 * Efilter Maximum Cartridge Flow rate, Qcart 7.5 gpm =q * (7.5 ft2/cartridge) Mass load per cartridge, Mcart (lbs)36 lbs =lookup mass load per cartridge Number of Cartridges required, Nmass 23 =ROUNDUP(Mfilter/Mcart,0) Maximum Treatment Capacity 0.38 =Nmass*(Qcart/449) SUMMARY Maximum Treatment Flow Rate, cfs 0.38 Target Pollutant(s):TSS Cartridge Flow Rate, gpm 7.5 Media:Perlite Number of Cartridges 23 Stormfilter Size 8'x12' Vault Determining Number of Cartridges for Volume-Based Design in NC ©2008 CONTECH Stormwater Solutions contechstormwater.com 1 of 1 lrs 5/14/2024 Enter Pipe I.D.=72 in.Total CMP Length=836 ft. Enter Desired Increment =1 in.System Invert=11.00 ft. Inc Num Water Level (in.) Inc Area (sq. ft.) Hyd Rad (ft.) Top Width (ft.) Volume (cf) WS Elevatio n (ft.) 1 1 0.08 0.06 1.40 65 11.08 2 2 0.22 0.11 1.97 184 11.17 3 3 0.40 0.16 2.40 337 11.25 4 4 0.62 0.22 2.75 517 11.33 5 5 0.86 0.27 3.05 719 11.42 6 6 1.13 0.32 3.32 941 11.50 7 7 1.41 0.37 3.56 1180 11.58 8 8 1.72 0.42 3.77 1436 11.67 9 9 2.04 0.47 3.97 1705 11.75 10 10 2.38 0.52 4.15 1988 11.83 11 11 2.73 0.57 4.32 2283 11.92 12 12 3.10 0.61 4.47 2589 12.00 13 13 3.48 0.66 4.62 2906 12.08 14 14 3.87 0.71 4.75 3232 12.17 15 15 4.27 0.75 4.87 3568 12.25 16 16 4.68 0.79 4.99 3911 12.33 17 17 5.10 0.84 5.10 4263 12.42 18 18 5.53 0.88 5.20 4621 12.50 19 19 5.96 0.92 5.29 4986 12.58 20 20 6.41 0.96 5.37 5358 12.67 21 21 6.86 1.00 5.45 5735 12.75 22 22 7.32 1.04 5.53 6118 12.83 23 23 7.78 1.08 5.60 6505 12.92 24 24 8.25 1.12 5.66 6897 13.00 25 25 8.72 1.15 5.71 7293 13.08 WQVadj WSE 26 26 9.20 1.19 5.76 7693 13.17 27 27 9.68 1.22 5.81 8096 13.25 28 28 10.17 1.26 5.85 8502 13.33 29 29 10.66 1.29 5.89 8911 13.42 30 30 11.15 1.32 5.92 9322 13.50 31 31 11.65 1.36 5.94 9735 13.58 32 32 12.14 1.39 5.96 10150 13.67 33 33 12.64 1.42 5.98 10566 13.75 34 34 13.14 1.45 5.99 10983 13.83 35 35 13.64 1.47 6.00 11401 13.92 Round Pipe Stage Storage Table Contech Engineered Solutions, LLC Engineer: Date Project Name Site Information Total Volume/LF 28.27 Sheetz - Shade Tree REV4 NC Wilmington Project State Project Location These results are submitted to you as a guideline only, without liability on the part of CONTECH Construction Products Inc. for accuracy or suitability to any particular application, and are subject to your verification. 36 36 14.14 1.50 6.00 11819 14.00 37 37 14.64 1.53 6.00 12237 14.08 38 38 15.14 1.55 5.99 12654 14.17 39 39 15.64 1.58 5.98 13071 14.25 40 40 16.13 1.60 5.96 13487 14.33 41 41 16.63 1.62 5.94 13902 14.42 42 42 17.12 1.64 5.92 14315 14.50 43 43 17.62 1.66 5.89 14726 14.58 44 44 18.10 1.68 5.85 15135 14.67 45 45 18.59 1.70 5.81 15541 14.75 46 46 19.07 1.72 5.76 15944 14.83 47 47 19.55 1.73 5.71 16344 14.92 48 48 20.02 1.75 5.66 16740 15.00 49 49 20.49 1.76 5.60 17132 15.08 50 50 20.96 1.77 5.53 17520 15.17 51 51 21.41 1.78 5.45 17902 15.25 52 52 21.87 1.79 5.37 18279 15.33 53 53 22.31 1.80 5.29 18651 15.42 54 54 22.75 1.81 5.20 19016 15.50 55 55 23.18 1.82 5.10 19375 15.58 56 56 23.60 1.82 4.99 19726 15.67 57 57 24.01 1.82 4.87 20070 15.75 58 58 24.41 1.83 4.75 20405 15.83 59 59 24.80 1.83 4.62 20731 15.92 60 60 25.18 1.82 4.47 21048 16.00 61 61 25.54 1.82 4.32 21354 16.08 62 62 25.90 1.82 4.15 21649 16.17 63 63 26.23 1.81 3.97 21932 16.25 64 64 26.56 1.80 3.77 22202 16.33 65 65 26.86 1.79 3.56 22457 16.42 66 66 27.15 1.77 3.32 22697 16.50 67 67 27.41 1.75 3.05 22918 16.58 68 68 27.66 1.73 2.75 23121 16.67 69 69 27.87 1.70 2.40 23300 16.75 70 70 28.05 1.67 1.97 23453 16.83 71 71 28.20 1.62 1.40 23572 16.92 72 72 28.27 1.50 0.00 23637 17.00 These results are submitted to you as a guideline only, without liability on the part of CONTECH Construction Products Inc. for accuracy or suitability to any particular application, and are subject to your verification. Volume StormFilter Outflow & Orifice Calculation Wilmington, NC Input Calculated Date:5/14/24 By:lrs Discharge flow rate from StormFilter: Restrictor Disc Diameter (in)0.443 Restrictor Disc Diameter (ft)0.037 Restrictor Disk Calibration: 0.61 0.0011 10 0.017 7.5 Sheetz - Shade Tree Lane REV1 Specific Data: 6.5 22 Flow Rate per Cartridge: 0.0134 6.01 Total Unit Outflow: 0.0134 0.2948 During the worst-case scenario, there is 6.5 feet of head available on the orifice. Flow, Q (cfs) Flow, Q (gpm) Number of cartridges With 22 cartridges, the total StormFilter discharge outflow rate is 0.2948 cfs during the worst-case scenario. Project Name:Sheetz - Shade Tree Lane REV1 Contech No:792,671 The Volume StormFilter restrictor disc is calibrated to flow at 7.5 gpm at 10 feet of head, or 1 gpm/sf or less for all cartridge sizes Orifice Coefficient Area of Restrictor Disc (sf) Head, h (ft) Flow, Q (cfs) Flow, Q (gpm) Max. Head, h, on Cartridges (ft) Flow, Q (cfs) per cartridge Flow, Q (cfs) total (Q = No. Cartridges x Flow per Cartridge) With 6.5 of head available, each cartridge will discharge 6.01 gpm, or 0.0134 cfs. Since 6.01 gpm is less than the 1 GPM/sf flow rate for the 18 inch cartridge, the mass loading calculations are preserved and 22 cartridges are suitable for this site. Equivalent Orifice Diameter: 0.2948 0.61 6.5 0.173 2.081 This equivalent orifice, however, it not a physical orifice. It is simply a method for accounting for the flow through the Volume StormFilter in routing calculations when required. Total Outflow (cfs) Orifice Coefficent Max. Head on cartridges (ft) Equivalent Diameter, D (ft) Equivalent Diameter, D (in) The following equations back-calculate from the total worst-case StormFilter flow rate and head to determine an equivalent orifice diameter that can be used to represent the StormFilter when designed on a volume/mass basis. 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