HomeMy WebLinkAbout04-SIA Narrative
GORDON ROAD FIRE STATION
STORMWATER IMPACT STATEMENT
AUGUST 2, 2024
PREPARED BY:
Will Altman, P.E.
5410 Trinity Road, Suite 102
Raleigh, North Carolina 27607
919.866.4938 phone
919.866.4951 fax
william.altman@timmons.com
www.timmons.com
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
Table of Contents
Section 1: Site Analysis and Narrative
Project Data
Project Descriptions
Stormwater Drainage Narrative
Calculation Method
Summary of Results
Pre/Post Summary Tables
Section 2: Environmental Maps
USGS Map
Soil Map
FEMA FIRM Map
Section 3: Stormwater Calculations
Pre/Post Calculations
Bioretention Pond Calculations
HGL Calculations
Rip Rap Calculations
Culvert Calculations
Erosion Calculations
Section 4: Stormwater Compliance
Pre/Post Stormwater Maps
Nutrient Loading
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Section 1: Site Analysis and Narrative
Project Data
Parcel Identification Number: R04300-008-346-000
River Basin: Cape Fear
Ex. Impervious on-site and off-site: 0.00 Acres
Post Project Impervious (Onsite): 1.28 Acres
Post Project Impervious (Offsite): 0.50 Acres
Post Project Impervious (Future offsite): 0.18 Acres
Area of Land Disturbance (onsite): 2.77 Acres
Area of Land Disturbance (offsite): 3.08 Acres
Project Description
The site is located at the intersection of Gordon Road and Harris Road in New Hanover County, NC. It contains
approximately 2.77 acres of woods that are undeveloped and has no existing impervious surfaces. A driveway is
proposed to access the site from Gordon Road. The proposed features include a fire station and associated parking
areas. Most of the proposed impervious areas will be treated with a bioretention cell while the rest will be bypassed.
The site is made up of one high density area and two low density areas, one of which is offsite. Most of the high-density
drainage area A is treated using a bioretention cell that meets the relevant MDC set forth in rules .1050 through .1062.
This drainage area is 1.93 acres, of which 1.19 acres is impervious. The 0.29 acres of drainage area A (0.07 acres of
which is impervious) that is not treated by the bioretention cell is bypassed. The low-density drainage area B is 0.44
acres, of which 0.01 acres is impervious. Low-density drainage area C (offsite) is 3.37 acres, of which 0.5 acres are
impervious. There is also expected to be another 0.18 acres of impervious area from the 3.37 acres for future road
improvements by the NCDOT. The rest of the pervious area cannot be developed in the future in order to maintain the
low-density area requirements. These densities are below the maximum density threshold set forth in the stormwater
Rules .1017, .1019, and .1021 of 15A NCAC 02H .1003. The flow is dispersed using vegetative conveyances and
culverts.
Stormwater Drainage Narrative
The site is in the Cape Fear River Basin. According to the USDA Web Soils Survey, the site is made up of primarily Ly,
Se, and Kr soils. Soils on the site are mostly sandy soils, with a hydrologic soil group A and D, based upon the New
Hanover County Stormwater Manual and the USGS Web Soils Survey. A review of Flood Hazard Areas based on the
published maps and the NC Flood plain Mapping Information System indicate that the site is not in any flood zones.
Calculation Method
The hydraulic grade line (HGL) model was performed using Storm Sewers software, which utilizes Modified Rational
methodology. Rainfall data was input based on NOAA’s rainfall data. Time of concentration was calculated using TR-55
segmented. The NRCS Unit hydrograph method was utilized for calculations of pre-development and post-development
conditions including the routing of the bioretention pond. Calculations were performed for the 1-year, 2-year, 10-year, 25-
year, and 100-year 24-hour storm event.
Summary of Results
There will be one bioretention pond onsite that captures and treats approximately 1.93 acres, of which 1.19 acres are
impervious. The site is graded in a way to direct most of the water onsite into the bioretention pond with the assistance of
storm pipes while the rest of the site and all the offsite work attempts to maintain similar flow patterns as before with the
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
use of ditches and culverts. The bioretention cell is utilized to meet the pre-development and post-development quantity
requirements for both county and state, minimizing flow.
Pre/Post Summary Tables
Site Analysis
Site Condition Storm Event
1 Year (cfs) 2 Year (cfs) 10 Year (cfs) 25 Year (cfs) 100 Year (cfs)
Pre-Development
Analysis Point A 1.13 1.81 4.29 6.25 10.16
Post-Development
A1 Bioretention
(High Density)
4.92 6.48 11.49 15.07 21.90
Post-Development
A2 (Low Density) 0.12 0.25 0.79 1.25 2.21
Post-Analysis A
Combined 0.12 0.25 3.77 5.37 8.69
Pre-Development
B 0.69 1.41 4.51 7.13 12.63
Post-Development
B 0.49 0.81 2.02 2.99 4.95
Pre-Development C 5.02 7.37 15.54 21.72 33.79
Post-Development
C 6.75 9.34 17.92 24.20 36.27
Permit and Easement Requirements
On the federal level, the US Army Corps of Engineers will be reviewing impact map permits. On the state level, the
NCDEQ will be reviewing the sanitary sewer permit, water main permit, erosion control permit, and stormwater permit.
The NCDOT will be reviewing the Driveway and Encroachment permit. On the local level, New Hanover County will be
reviewing this stormwater permit and site permit. The sanitary sewer force main will require a 20’ private utility easement.
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Section 2: Environmental Maps
SCALE:
DATE:
FIGURE NO.
1AS SHOWN
1/17/2024NHC Gordon Road Fire Station
Wilmington, North Carolina
Test Location Sketch
C-1
C-3C-4 C-2
C-7
C-5
Legend
CPT Sounding
Hand Auger Boring
Image Courtesy of Stewart Cooper Newell Architects
C-6
C-8
P-1P-2
P-3P-4
P-5
P-6
P-7
P-8
P-9
P-10
C-9
C-10
A
A’
PROJECT NO.:
23060170
SW-3
SW-2
SW-1
TOPSOIL - 2 Inches
SILTY SAND (SM) - Gray and black, mostly fine sand, some low plasticity to non-plastic fines, moist.
- - - Brown
POORLY GRADED SAND WITH SILT (SP-SM) - Brown, mostly fine sand, few low plasticity to non-plastic fines,
moist.
Boring terminated at 6 ft
Target Depth
HAND AUGER BORING LOG: SW-1
DATE FINISHED:
23060170
DATE STARTED:
Wilmington, North Carolina
1/15/24 1/15/24
S&ME/C. Anderson
Not Encountered.
Hand Auger
WATER LEVEL:
NHC Gordon Road Fire Station
SAMPLING METHOD:
PROJECT:
PERFORMED BY:
NOTES:
Page 1 of 1
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MATERIAL DESCRIPTION
Elevation Unkown
TOPSOIL - 1 Inch
POORLY GRADED SAND WITH SILT (SP-SM) - Gray, mostly fine sand, few low plasticity to non-plastic fines,
moist.
SILTY SAND (SM) - Brown, mostly fine sand, some low plasticity to non-plastic fines, moist.
POORLY GRADED SAND WITH SILT (SP-SM) - Brown, mostly fine sand, few low plasticity to non-plastic fines,
moist.
Boring terminated at 6 ft
Target Depth
HAND AUGER BORING LOG: SW-2
DATE FINISHED:
23060170
DATE STARTED:
Wilmington, North Carolina
1/15/24 1/15/24
S&ME/C. Anderson
Not Encountered.
Hand Auger
WATER LEVEL:
NHC Gordon Road Fire Station
SAMPLING METHOD:
PROJECT:
PERFORMED BY:
NOTES:
Page 1 of 1
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MATERIAL DESCRIPTION
Elevation Unkown
TOPSOIL - 1 Inch
POORLY GRADED SAND WITH SILT (SP-SM) - Very loose, gray, mostly fine sand, few low plasticity to
non-plastic fines, moist.
- - - Brown
Boring terminated at 6 ft
Target Depth
HAND AUGER BORING LOG: SW-3
DATE FINISHED:
23060170
DATE STARTED:
Wilmington, North Carolina
1/15/24 1/15/24
S&ME/C. Anderson
Not Encountered.
Hand Auger
WATER LEVEL:
NHC Gordon Road Fire Station
SAMPLING METHOD:
PROJECT:
PERFORMED BY:
NOTES:
Page 1 of 1
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MATERIAL DESCRIPTION
Elevation Unkown
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
USGS Map
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Soil Map
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
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
10
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
Be Baymeade fine sand, 1 to 6
percent slopes
29.7 23.0%
Kr Kureb sand, 1 to 8 percent
slopes
34.4 26.6%
Le Leon sand 9.7 7.5%
Ly Lynn Haven fine sand 21.0 16.2%
Mu Murville fine sand 6.7 5.2%
Se Seagate fine sand 27.8 21.5%
Totals for Area of Interest 129.3 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
Custom Soil Resource Report
11
5/9/24, 11:40 AM BookReaderImages.php (2626×4079)
https://ia904701.us.archive.org/BookReader/BookReaderImages.php?zip=/28/items/usda-soil-survey-of-new-hanover-county-north-carolina-1906/usd…1/1
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
FEMA FIRM Map
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 4/2/2024 at 5:32 PM 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°51'41"W 34°16'30"N
77°51'4"W 34°16'N
Basemap Imagery Source: USGS National Map 2023
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Section 3: Stormwater Calculations
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Pre/Post Calculations
1 2 3 4
56 7
8
9
Watershed Model Schematic Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023
Project: SCS-Gordon Road.gpw Tuesday, 07 / 23 / 2024
Hyd.Origin Description
Legend
1 SCS Runoff Pre Analysis Point A
2 SCS Runoff Pre Analysis Point B
3 SCS Runoff Post Analysis Point A - High Density
4 SCS Runoff Post Analysis Point A - Low Density
5 SCS Runoff Post Analysis Point B
6 SCS Runoff Pre Analysis Point C
7 SCS Runoff Post Analysis Point C
8 Reservoir Bio
9 Combine Post Analysis A- Combined
Hydraflow Table of Contents SCS-Gordon Road.gpw
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Watershed Model Schematic...................................................................................... 1
Hydrograph Return Period Recap............................................................................. 2
1 - Year
Summary Report......................................................................................................................... 3
Hydrograph Reports................................................................................................................... 4
Hydrograph No. 1, SCS Runoff, Pre Analysis Point A.............................................................. 4
Hydrograph No. 2, SCS Runoff, Pre Analysis Point B.............................................................. 5
Hydrograph No. 3, SCS Runoff, Post Analysis Point A - High Density..................................... 6
Hydrograph No. 4, SCS Runoff, Post Analysis Point A - Low Density...................................... 7
Hydrograph No. 5, SCS Runoff, Post Analysis Point B............................................................ 8
Hydrograph No. 6, SCS Runoff, Pre Analysis Point C............................................................. 9
Hydrograph No. 7, SCS Runoff, Post Analysis Point C.......................................................... 10
Hydrograph No. 8, Reservoir, Bio........................................................................................... 11
Pond Report - Bio Retention.............................................................................................. 12
Hydrograph No. 9, Combine, Post Analysis A- Combined.....................................................14
2 - Year
Summary Report....................................................................................................................... 15
Hydrograph Reports................................................................................................................. 16
Hydrograph No. 1, SCS Runoff, Pre Analysis Point A............................................................ 16
Hydrograph No. 2, SCS Runoff, Pre Analysis Point B............................................................ 17
Hydrograph No. 3, SCS Runoff, Post Analysis Point A - High Density................................... 18
Hydrograph No. 4, SCS Runoff, Post Analysis Point A - Low Density.................................... 19
Hydrograph No. 5, SCS Runoff, Post Analysis Point B.......................................................... 20
Hydrograph No. 6, SCS Runoff, Pre Analysis Point C........................................................... 21
Hydrograph No. 7, SCS Runoff, Post Analysis Point C.......................................................... 22
Hydrograph No. 8, Reservoir, Bio........................................................................................... 23
Hydrograph No. 9, Combine, Post Analysis A- Combined.....................................................24
10 - Year
Summary Report....................................................................................................................... 25
Hydrograph Reports................................................................................................................. 26
Hydrograph No. 1, SCS Runoff, Pre Analysis Point A............................................................ 26
Hydrograph No. 2, SCS Runoff, Pre Analysis Point B............................................................ 27
Hydrograph No. 3, SCS Runoff, Post Analysis Point A - High Density................................... 28
Hydrograph No. 4, SCS Runoff, Post Analysis Point A - Low Density.................................... 29
Hydrograph No. 5, SCS Runoff, Post Analysis Point B.......................................................... 30
Hydrograph No. 6, SCS Runoff, Pre Analysis Point C........................................................... 31
Hydrograph No. 7, SCS Runoff, Post Analysis Point C.......................................................... 32
Hydrograph No. 8, Reservoir, Bio........................................................................................... 33
Hydrograph No. 9, Combine, Post Analysis A- Combined.....................................................34
25 - Year
Summary Report....................................................................................................................... 35
Hydrograph Reports................................................................................................................. 36
Hydrograph No. 1, SCS Runoff, Pre Analysis Point A............................................................ 36
Contents continued...SCS-Gordon Road.gpw
Hydrograph No. 2, SCS Runoff, Pre Analysis Point B............................................................ 37
Hydrograph No. 3, SCS Runoff, Post Analysis Point A - High Density................................... 38
Hydrograph No. 4, SCS Runoff, Post Analysis Point A - Low Density.................................... 39
Hydrograph No. 5, SCS Runoff, Post Analysis Point B.......................................................... 40
Hydrograph No. 6, SCS Runoff, Pre Analysis Point C........................................................... 41
Hydrograph No. 7, SCS Runoff, Post Analysis Point C.......................................................... 42
Hydrograph No. 8, Reservoir, Bio........................................................................................... 43
Hydrograph No. 9, Combine, Post Analysis A- Combined.....................................................44
100 - Year
Summary Report....................................................................................................................... 45
Hydrograph Reports................................................................................................................. 46
Hydrograph No. 1, SCS Runoff, Pre Analysis Point A............................................................ 46
Hydrograph No. 2, SCS Runoff, Pre Analysis Point B............................................................ 47
Hydrograph No. 3, SCS Runoff, Post Analysis Point A - High Density................................... 48
Hydrograph No. 4, SCS Runoff, Post Analysis Point A - Low Density.................................... 49
Hydrograph No. 5, SCS Runoff, Post Analysis Point B.......................................................... 50
Hydrograph No. 6, SCS Runoff, Pre Analysis Point C........................................................... 51
Hydrograph No. 7, SCS Runoff, Post Analysis Point C.......................................................... 52
Hydrograph No. 8, Reservoir, Bio........................................................................................... 53
Hydrograph No. 9, Combine, Post Analysis A- Combined.....................................................54
IDF Report.................................................................................................................. 55
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 1.127 2 724 3,768 ------ ------ ------ Pre Analysis Point A
2 SCS Runoff 0.689 2 726 3,132 ------ ------ ------ Pre Analysis Point B
3 SCS Runoff 4.915 2 724 14,709 ------ ------ ------ Post Analysis Point A - High Density
4 SCS Runoff 0.120 2 726 547 ------ ------ ------ Post Analysis Point A - Low Density
5 SCS Runoff 0.486 2 724 1,695 ------ ------ ------ Post Analysis Point B
6 SCS Runoff 5.015 2 724 15,550 ------ ------ ------ Pre Analysis Point C
7 SCS Runoff 6.747 2 724 20,278 ------ ------ ------ Post Analysis Point C
8 Reservoir 0.000 2 742 0 3 43.89 7,667 Bio
9 Combine 0.120 2 726 547 4, 8 ------ ------ Post Analysis A- Combined
SCS-Gordon Road.gpw Return Period: 1 Year Friday, 07 / 12 / 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 Friday, 07 / 12 / 2024
Hyd. No. 1
Pre Analysis Point A
Hydrograph type = SCS Runoff Peak discharge = 1.127 cfs
Storm frequency = 1 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 3,768 cuft
Drainage area = 1.110 ac Curve number = 66*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.85 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.820 x 77) + (0.290 x 36)] / 1.110
4
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
Q (cfs)
Time (min)
Pre Analysis Point A
Hyd. No. 1 -- 1 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 2
Pre Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 0.689 cfs
Storm frequency = 1 yrs Time to peak = 726 min
Time interval = 2 min Hyd. volume = 3,132 cuft
Drainage area = 1.660 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.85 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.750 x 83) + (0.910 x 36)] / 1.660
5
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
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)
Pre Analysis Point B
Hyd. No. 2 -- 1 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 3
Post Analysis Point A - High Density
Hydrograph type = SCS Runoff Peak discharge = 4.915 cfs
Storm frequency = 1 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 14,709 cuft
Drainage area = 1.930 ac Curve number = 84*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.85 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.190 x 98) + (0.350 x 39) + (0.390 x 80)] / 1.930
6
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
Q (cfs)
Time (min)
Post Analysis Point A - High Density
Hyd. No. 3 -- 1 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 4
Post Analysis Point A - Low Density
Hydrograph type = SCS Runoff Peak discharge = 0.120 cfs
Storm frequency = 1 yrs Time to peak = 726 min
Time interval = 2 min Hyd. volume = 547 cuft
Drainage area = 0.290 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.85 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.070 x 98) + (0.030 x 39) + (0.190 x 80)] / 0.290
7
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)
Post Analysis Point A - Low Density
Hyd. No. 4 -- 1 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 5
Post Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 0.486 cfs
Storm frequency = 1 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 1,695 cuft
Drainage area = 0.560 ac Curve number = 64*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.85 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.320 x 80) + (0.230 x 39)] / 0.560
8
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)
Post Analysis Point B
Hyd. No. 5 -- 1 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 6
Pre Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 5.015 cfs
Storm frequency = 1 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 15,550 cuft
Drainage area = 3.370 ac Curve number = 72
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.85 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
5.00 5.00
6.00 6.00
Q (cfs)
Time (min)
Pre Analysis Point C
Hyd. No. 6 -- 1 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 7
Post Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 6.747 cfs
Storm frequency = 1 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 20,278 cuft
Drainage area = 3.370 ac Curve number = 78*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 3.85 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.680 x 98) + (2.690 x 69)] / 3.370
10
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
7.00 7.00
Q (cfs)
Time (min)
Post Analysis Point C
Hyd. No. 7 -- 1 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 8
Bio
Hydrograph type = Reservoir Peak discharge = 0.000 cfs
Storm frequency = 1 yrs Time to peak = 742 min
Time interval = 2 min Hyd. volume = 0 cuft
Inflow hyd. No. = 3 - Post Analysis Point A - High DensityMax. Elevation = 43.89 ft
Reservoir name = Bio Retention Max. Storage = 7,667 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
11
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
3.00 3.00
4.00 4.00
5.00 5.00
Q (cfs)
Time (min)
Bio
Hyd. No. 8 -- 1 Year
Hyd No. 8 Hyd No. 3 Total storage used = 7,667 cuft
Pond Report 12
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Pond No. 1 - Bio Retention
Pond Data
Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 43.00 ft
Stage / Storage Table
Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft)
0.00 43.00 7,767 0 0
1.00 44.00 9,523 8,629 8,629
2.00 45.00 11,354 10,424 19,053
3.00 46.00 13,243 12,285 31,338
3.50 46.50 14,208 6,861 38,199
Culvert / Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr] [A] [B] [C] [D]
Rise (in)= 10.00 Inactive 0.00 0.00
Span (in)= 10.00 36.00 0.00 0.00
No. Barrels = 1 1 0 0
Invert El. (ft)= 39.42 44.50 0.00 0.00
Length (ft)= 100.00 0.00 0.00 0.00
Slope (%)= 0.50 0.00 0.00 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)= 16.00 20.00 0.00 0.00
Crest El. (ft)= 44.50 45.50 0.00 0.00
Weir Coeff.= 3.33 2.60 3.33 3.33
Weir Type = 1 Broad --- ---
Multi-Stage = Yes No No No
Exfil.(in/hr)= 2.000 (by Contour)
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).
Stage / Storage / Discharge Table
Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total
ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs
0.00 0 43.00 0.00 0.00 --- --- 0.00 0.00 --- --- 0.000 --- 0.000
0.10 863 43.10 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.044 ---0.044
0.20 1,726 43.20 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.088 --- 0.088
0.30 2,589 43.30 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.132 --- 0.132
0.40 3,452 43.40 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.176 --- 0.176
0.50 4,315 43.50 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.220 --- 0.220
0.60 5,178 43.60 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.265 --- 0.265
0.70 6,040 43.70 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.309 --- 0.309
0.80 6,903 43.80 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.353 --- 0.353
0.90 7,766 43.90 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.397 --- 0.397
1.00 8,629 44.00 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.441 --- 0.441
1.10 9,672 44.10 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.449 --- 0.449
1.20 10,714 44.20 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.458 --- 0.458
1.30 11,756 44.30 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.466 --- 0.466
1.40 12,799 44.40 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.475 --- 0.475
1.50 13,841 44.50 3.38 oc 0.00 --- --- 0.00 0.00 --- --- 0.483 --- 0.483
1.60 14,884 44.60 3.38 oc 0.00 --- --- 1.68 0.00 --- --- 0.492 --- 2.176
1.70 15,926 44.70 4.12 oc 0.00 --- --- 4.12 s 0.00 --- --- 0.500 --- 4.624
1.80 16,968 44.80 4.20 oc 0.00 --- --- 4.20 s 0.00 --- --- 0.509 --- 4.705
1.90 18,011 44.90 4.25 oc 0.00 --- --- 4.25 s 0.00 --- --- 0.517 --- 4.764
2.00 19,053 45.00 4.29 oc 0.00 --- --- 4.27 s 0.00 --- --- 0.526 --- 4.801
2.10 20,282 45.10 4.33 oc 0.00 --- --- 4.32 s 0.00 --- --- 0.534 --- 4.857
2.20 21,510 45.20 4.37 oc 0.00 --- --- 4.36 s 0.00 --- --- 0.543 --- 4.900
2.30 22,739 45.30 4.41 oc 0.00 --- --- 4.36 s 0.00 --- --- 0.552 --- 4.911
2.40 23,967 45.40 4.45 oc 0.00 --- --- 4.41 s 0.00 --- --- 0.561 --- 4.975
2.50 25,196 45.50 4.49 oc 0.00 --- --- 4.36 s 0.00 --- --- 0.569 --- 4.932
2.60 26,424 45.60 4.53 oc 0.00 --- --- 4.46 s 1.64 --- --- 0.578 --- 6.685
2.70 27,653 45.70 4.57 oc 0.00 --- --- 4.41 s 4.65 --- --- 0.587 --- 9.645
2.80 28,881 45.80 4.61 oc 0.00 --- --- 4.51 s 8.54 --- --- 0.596 --- 13.65
2.90 30,110 45.90 4.65 oc 0.00 --- --- 4.50 s 13.15 --- --- 0.604 --- 18.26
3.00 31,338 46.00 4.69 oc 0.00 --- --- 4.43 s 18.38 --- --- 0.613 --- 23.43
3.05 32,025 46.05 4.70 oc 0.00 --- --- 4.59 s 21.21 --- --- 0.618 --- 26.42
3.10 32,711 46.10 4.72 oc 0.00 --- --- 4.13 s 24.17 --- --- 0.622 --- 28.92
3.15 33,397 46.15 4.74 oc 0.00 --- --- 4.30 s 27.25 --- --- 0.627 --- 32.17
3.20 34,083 46.20 4.76 oc 0.00 --- --- 4.44 s 30.45 --- --- 0.631 --- 35.53
3.25 34,769 46.25 4.78 oc 0.00 --- --- 4.59 s 33.77 --- --- 0.635 --- 39.00
3.30 35,455 46.30 4.80 oc 0.00 --- --- 4.74 s 37.21 --- --- 0.640 --- 42.58
3.35 36,141 46.35 4.82 oc 0.00 --- --- 3.81 s 40.75 --- --- 0.644 --- 45.20
Continues on next page...
13
Bio Retention
Stage / Storage / Discharge Table
Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total
ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs
3.40 36,827 46.40 4.83 oc 0.00 --- --- 3.92 s 44.40 --- --- 0.649 --- 48.97
3.45 37,513 46.45 4.85 oc 0.00 --- --- 4.04 s 48.15 --- --- 0.653 --- 52.84
3.50 38,199 46.50 4.87 oc 0.00 --- --- 4.30 s 52.00 --- --- 0.658 --- 56.96
...End
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 9
Post Analysis A- Combined
Hydrograph type = Combine Peak discharge = 0.120 cfs
Storm frequency = 1 yrs Time to peak = 726 min
Time interval = 2 min Hyd. volume = 547 cuft
Inflow hyds. = 4, 8 Contrib. drain. area = 0.290 ac
14
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)
Post Analysis A- Combined
Hyd. No. 9 -- 1 Year
Hyd No. 9 Hyd No. 4 Hyd No. 8
Hydrograph Summary Report
15
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 1.806 2 724 5,692 ------ ------ ------ Pre Analysis Point A
2 SCS Runoff 1.410 2 724 5,274 ------ ------ ------ Pre Analysis Point B
3 SCS Runoff 6.483 2 724 19,507 ------ ------ ------ Post Analysis Point A - High Density
4 SCS Runoff 0.246 2 724 921 ------ ------ ------ Post Analysis Point A - Low Density
5 SCS Runoff 0.810 2 724 2,612 ------ ------ ------ Post Analysis Point B
6 SCS Runoff 7.369 2 724 22,329 ------ ------ ------ Pre Analysis Point C
7 SCS Runoff 9.337 2 724 27,914 ------ ------ ------ Post Analysis Point C
8 Reservoir 0.000 2 1114 0 3 44.18 10,525 Bio
9 Combine 0.246 2 724 921 4, 8 ------ ------ Post Analysis A- Combined
SCS-Gordon Road.gpw Return Period: 2 Year Friday, 07 / 12 / 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 Friday, 07 / 12 / 2024
Hyd. No. 1
Pre Analysis Point A
Hydrograph type = SCS Runoff Peak discharge = 1.806 cfs
Storm frequency = 2 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 5,692 cuft
Drainage area = 1.110 ac Curve number = 66*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 4.67 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.820 x 77) + (0.290 x 36)] / 1.110
16
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
Q (cfs)
Time (min)
Pre Analysis Point A
Hyd. No. 1 -- 2 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 2
Pre Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 1.410 cfs
Storm frequency = 2 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 5,274 cuft
Drainage area = 1.660 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 4.67 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.750 x 83) + (0.910 x 36)] / 1.660
17
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
Q (cfs)
Time (min)
Pre Analysis Point B
Hyd. No. 2 -- 2 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 3
Post Analysis Point A - High Density
Hydrograph type = SCS Runoff Peak discharge = 6.483 cfs
Storm frequency = 2 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 19,507 cuft
Drainage area = 1.930 ac Curve number = 84*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 4.67 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.190 x 98) + (0.350 x 39) + (0.390 x 80)] / 1.930
18
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
7.00 7.00
Q (cfs)
Time (min)
Post Analysis Point A - High Density
Hyd. No. 3 -- 2 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 4
Post Analysis Point A - Low Density
Hydrograph type = SCS Runoff Peak discharge = 0.246 cfs
Storm frequency = 2 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 921 cuft
Drainage area = 0.290 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 4.67 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.070 x 98) + (0.030 x 39) + (0.190 x 80)] / 0.290
19
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)
Post Analysis Point A - Low Density
Hyd. No. 4 -- 2 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 5
Post Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 0.810 cfs
Storm frequency = 2 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 2,612 cuft
Drainage area = 0.560 ac Curve number = 64*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 4.67 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.320 x 80) + (0.230 x 39)] / 0.560
20
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
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)
Post Analysis Point B
Hyd. No. 5 -- 2 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 6
Pre Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 7.369 cfs
Storm frequency = 2 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 22,329 cuft
Drainage area = 3.370 ac Curve number = 72
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 4.67 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
2.00 2.00
4.00 4.00
6.00 6.00
8.00 8.00
Q (cfs)
Time (min)
Pre Analysis Point C
Hyd. No. 6 -- 2 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 7
Post Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 9.337 cfs
Storm frequency = 2 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 27,914 cuft
Drainage area = 3.370 ac Curve number = 78*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 4.67 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.680 x 98) + (2.690 x 69)] / 3.370
22
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)
Post Analysis Point C
Hyd. No. 7 -- 2 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 8
Bio
Hydrograph type = Reservoir Peak discharge = 0.000 cfs
Storm frequency = 2 yrs Time to peak = 1114 min
Time interval = 2 min Hyd. volume = 0 cuft
Inflow hyd. No. = 3 - Post Analysis Point A - High DensityMax. Elevation = 44.18 ft
Reservoir name = Bio Retention Max. Storage = 10,525 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
23
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
7.00 7.00
Q (cfs)
Time (min)
Bio
Hyd. No. 8 -- 2 Year
Hyd No. 8 Hyd No. 3 Total storage used = 10,525 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 9
Post Analysis A- Combined
Hydrograph type = Combine Peak discharge = 0.246 cfs
Storm frequency = 2 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 921 cuft
Inflow hyds. = 4, 8 Contrib. drain. area = 0.290 ac
24
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)
Post Analysis A- Combined
Hyd. No. 9 -- 2 Year
Hyd No. 9 Hyd No. 4 Hyd No. 8
Hydrograph Summary Report
25
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 4.292 2 724 12,881 ------ ------ ------ Pre Analysis Point A
2 SCS Runoff 4.511 2 724 14,054 ------ ------ ------ Pre Analysis Point B
3 SCS Runoff 11.49 2 724 35,384 ------ ------ ------ Post Analysis Point A - High Density
4 SCS Runoff 0.788 2 724 2,455 ------ ------ ------ Post Analysis Point A - Low Density
5 SCS Runoff 2.023 2 724 6,099 ------ ------ ------ Post Analysis Point B
6 SCS Runoff 15.54 2 724 46,465 ------ ------ ------ Pre Analysis Point C
7 SCS Runoff 17.92 2 724 54,032 ------ ------ ------ Post Analysis Point C
8 Reservoir 3.443 2 740 7,864 3 44.67 15,635 Bio
9 Combine 3.769 2 738 10,319 4, 8 ------ ------ Post Analysis A- Combined
SCS-Gordon Road.gpw Return Period: 10 Year Friday, 07 / 12 / 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 Friday, 07 / 12 / 2024
Hyd. No. 1
Pre Analysis Point A
Hydrograph type = SCS Runoff Peak discharge = 4.292 cfs
Storm frequency = 10 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 12,881 cuft
Drainage area = 1.110 ac Curve number = 66*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.26 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.820 x 77) + (0.290 x 36)] / 1.110
26
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
Q (cfs)
Time (min)
Pre Analysis Point A
Hyd. No. 1 -- 10 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 2
Pre Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 4.511 cfs
Storm frequency = 10 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 14,054 cuft
Drainage area = 1.660 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.26 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.750 x 83) + (0.910 x 36)] / 1.660
27
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
Q (cfs)
Time (min)
Pre Analysis Point B
Hyd. No. 2 -- 10 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 3
Post Analysis Point A - High Density
Hydrograph type = SCS Runoff Peak discharge = 11.49 cfs
Storm frequency = 10 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 35,384 cuft
Drainage area = 1.930 ac Curve number = 84*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.26 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.190 x 98) + (0.350 x 39) + (0.390 x 80)] / 1.930
28
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
Q (cfs)
Time (min)
Post Analysis Point A - High Density
Hyd. No. 3 -- 10 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 4
Post Analysis Point A - Low Density
Hydrograph type = SCS Runoff Peak discharge = 0.788 cfs
Storm frequency = 10 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 2,455 cuft
Drainage area = 0.290 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.26 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.070 x 98) + (0.030 x 39) + (0.190 x 80)] / 0.290
29
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
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)
Post Analysis Point A - Low Density
Hyd. No. 4 -- 10 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 5
Post Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 2.023 cfs
Storm frequency = 10 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 6,099 cuft
Drainage area = 0.560 ac Curve number = 64*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.26 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.320 x 80) + (0.230 x 39)] / 0.560
30
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
Q (cfs)
Time (min)
Post Analysis Point B
Hyd. No. 5 -- 10 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 6
Pre Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 15.54 cfs
Storm frequency = 10 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 46,465 cuft
Drainage area = 3.370 ac Curve number = 72
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.26 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
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)
Pre Analysis Point C
Hyd. No. 6 -- 10 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 7
Post Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 17.92 cfs
Storm frequency = 10 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 54,032 cuft
Drainage area = 3.370 ac Curve number = 78*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 7.26 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.680 x 98) + (2.690 x 69)] / 3.370
32
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
Q (cfs)
Time (min)
Post Analysis Point C
Hyd. No. 7 -- 10 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 8
Bio
Hydrograph type = Reservoir Peak discharge = 3.443 cfs
Storm frequency = 10 yrs Time to peak = 740 min
Time interval = 2 min Hyd. volume = 7,864 cuft
Inflow hyd. No. = 3 - Post Analysis Point A - High DensityMax. Elevation = 44.67 ft
Reservoir name = Bio Retention Max. Storage = 15,635 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
33
0 120 240 360 480 600 720 840 960
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)
Bio
Hyd. No. 8 -- 10 Year
Hyd No. 8 Hyd No. 3 Total storage used = 15,635 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 9
Post Analysis A- Combined
Hydrograph type = Combine Peak discharge = 3.769 cfs
Storm frequency = 10 yrs Time to peak = 738 min
Time interval = 2 min Hyd. volume = 10,319 cuft
Inflow hyds. = 4, 8 Contrib. drain. area = 0.290 ac
34
0 120 240 360 480 600 720 840 960
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)
Post Analysis A- Combined
Hyd. No. 9 -- 10 Year
Hyd No. 9 Hyd No. 4 Hyd No. 8
Hydrograph Summary Report
35
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 6.247 2 724 18,670 ------ ------ ------ Pre Analysis Point A
2 SCS Runoff 7.130 2 724 21,594 ------ ------ ------ Pre Analysis Point B
3 SCS Runoff 15.07 2 724 47,127 ------ ------ ------ Post Analysis Point A - High Density
4 SCS Runoff 1.246 2 724 3,772 ------ ------ ------ Post Analysis Point A - Low Density
5 SCS Runoff 2.991 2 724 8,944 ------ ------ ------ Post Analysis Point B
6 SCS Runoff 21.72 2 724 65,254 ------ ------ ------ Pre Analysis Point C
7 SCS Runoff 24.20 2 724 73,796 ------ ------ ------ Post Analysis Point C
8 Reservoir 4.290 2 740 16,874 3 45.03 19,432 Bio
9 Combine 5.374 2 724 20,647 4, 8 ------ ------ Post Analysis A- Combined
SCS-Gordon Road.gpw Return Period: 25 Year Friday, 07 / 12 / 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 Friday, 07 / 12 / 2024
Hyd. No. 1
Pre Analysis Point A
Hydrograph type = SCS Runoff Peak discharge = 6.247 cfs
Storm frequency = 25 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 18,670 cuft
Drainage area = 1.110 ac Curve number = 66*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 9.12 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.820 x 77) + (0.290 x 36)] / 1.110
36
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
7.00 7.00
Q (cfs)
Time (min)
Pre Analysis Point A
Hyd. No. 1 -- 25 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 2
Pre Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 7.130 cfs
Storm frequency = 25 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 21,594 cuft
Drainage area = 1.660 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 9.12 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.750 x 83) + (0.910 x 36)] / 1.660
37
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 Analysis Point B
Hyd. No. 2 -- 25 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 3
Post Analysis Point A - High Density
Hydrograph type = SCS Runoff Peak discharge = 15.07 cfs
Storm frequency = 25 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 47,127 cuft
Drainage area = 1.930 ac Curve number = 84*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 9.12 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.190 x 98) + (0.350 x 39) + (0.390 x 80)] / 1.930
38
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)
Post Analysis Point A - High Density
Hyd. No. 3 -- 25 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 4
Post Analysis Point A - Low Density
Hydrograph type = SCS Runoff Peak discharge = 1.246 cfs
Storm frequency = 25 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 3,772 cuft
Drainage area = 0.290 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 9.12 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.070 x 98) + (0.030 x 39) + (0.190 x 80)] / 0.290
39
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
Q (cfs)
Time (min)
Post Analysis Point A - Low Density
Hyd. No. 4 -- 25 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 5
Post Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 2.991 cfs
Storm frequency = 25 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 8,944 cuft
Drainage area = 0.560 ac Curve number = 64*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 9.12 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.320 x 80) + (0.230 x 39)] / 0.560
40
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
Q (cfs)
Time (min)
Post Analysis Point B
Hyd. No. 5 -- 25 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 6
Pre Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 21.72 cfs
Storm frequency = 25 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 65,254 cuft
Drainage area = 3.370 ac Curve number = 72
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 9.12 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
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)
Pre Analysis Point C
Hyd. No. 6 -- 25 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 7
Post Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 24.20 cfs
Storm frequency = 25 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 73,796 cuft
Drainage area = 3.370 ac Curve number = 78*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 9.12 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.680 x 98) + (2.690 x 69)] / 3.370
42
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)
Post Analysis Point C
Hyd. No. 7 -- 25 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 8
Bio
Hydrograph type = Reservoir Peak discharge = 4.290 cfs
Storm frequency = 25 yrs Time to peak = 740 min
Time interval = 2 min Hyd. volume = 16,874 cuft
Inflow hyd. No. = 3 - Post Analysis Point A - High DensityMax. Elevation = 45.03 ft
Reservoir name = Bio Retention Max. Storage = 19,432 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
43
0 120 240 360 480 600 720 840 960
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)
Bio
Hyd. No. 8 -- 25 Year
Hyd No. 8 Hyd No. 3 Total storage used = 19,432 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 9
Post Analysis A- Combined
Hydrograph type = Combine Peak discharge = 5.374 cfs
Storm frequency = 25 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 20,647 cuft
Inflow hyds. = 4, 8 Contrib. drain. area = 0.290 ac
44
0 120 240 360 480 600 720 840 960
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 Analysis A- Combined
Hyd. No. 9 -- 25 Year
Hyd No. 9 Hyd No. 4 Hyd No. 8
Hydrograph Summary Report
45
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 10.16 2 724 30,582 ------ ------ ------ Pre Analysis Point A
2 SCS Runoff 12.63 2 724 37,765 ------ ------ ------ Pre Analysis Point B
3 SCS Runoff 21.90 2 724 70,077 ------ ------ ------ Post Analysis Point A - High Density
4 SCS Runoff 2.207 2 724 6,597 ------ ------ ------ Post Analysis Point A - Low Density
5 SCS Runoff 4.947 2 724 14,845 ------ ------ ------ Post Analysis Point B
6 SCS Runoff 33.79 2 724 103,100 ------ ------ ------ Pre Analysis Point C
7 SCS Runoff 36.27 2 724 112,934 ------ ------ ------ Post Analysis Point C
8 Reservoir 7.753 2 736 35,131 3 45.66 27,109 Bio
9 Combine 8.687 2 736 41,728 4, 8 ------ ------ Post Analysis A- Combined
SCS-Gordon Road.gpw Return Period: 100 Year Friday, 07 / 12 / 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 Friday, 07 / 12 / 2024
Hyd. No. 1
Pre Analysis Point A
Hydrograph type = SCS Runoff Peak discharge = 10.16 cfs
Storm frequency = 100 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 30,582 cuft
Drainage area = 1.110 ac Curve number = 66*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.820 x 77) + (0.290 x 36)] / 1.110
46
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 Analysis Point A
Hyd. No. 1 -- 100 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 2
Pre Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 12.63 cfs
Storm frequency = 100 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 37,765 cuft
Drainage area = 1.660 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.750 x 83) + (0.910 x 36)] / 1.660
47
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)
Pre Analysis Point B
Hyd. No. 2 -- 100 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 3
Post Analysis Point A - High Density
Hydrograph type = SCS Runoff Peak discharge = 21.90 cfs
Storm frequency = 100 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 70,077 cuft
Drainage area = 1.930 ac Curve number = 84*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.190 x 98) + (0.350 x 39) + (0.390 x 80)] / 1.930
48
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
Q (cfs)
Time (min)
Post Analysis Point A - High Density
Hyd. No. 3 -- 100 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 4
Post Analysis Point A - Low Density
Hydrograph type = SCS Runoff Peak discharge = 2.207 cfs
Storm frequency = 100 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 6,597 cuft
Drainage area = 0.290 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.070 x 98) + (0.030 x 39) + (0.190 x 80)] / 0.290
49
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
Q (cfs)
Time (min)
Post Analysis Point A - Low Density
Hyd. No. 4 -- 100 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 5
Post Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 4.947 cfs
Storm frequency = 100 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 14,845 cuft
Drainage area = 0.560 ac Curve number = 64*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.320 x 80) + (0.230 x 39)] / 0.560
50
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
Q (cfs)
Time (min)
Post Analysis Point B
Hyd. No. 5 -- 100 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 6
Pre Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 33.79 cfs
Storm frequency = 100 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 103,100 cuft
Drainage area = 3.370 ac Curve number = 72
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 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
Q (cfs)
0.00 0.00
5.00 5.00
10.00 10.00
15.00 15.00
20.00 20.00
25.00 25.00
30.00 30.00
35.00 35.00
Q (cfs)
Time (min)
Pre Analysis Point C
Hyd. No. 6 -- 100 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 7
Post Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 36.27 cfs
Storm frequency = 100 yrs Time to peak = 724 min
Time interval = 2 min Hyd. volume = 112,934 cuft
Drainage area = 3.370 ac Curve number = 78*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.680 x 98) + (2.690 x 69)] / 3.370
52
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
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 Analysis Point C
Hyd. No. 7 -- 100 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 8
Bio
Hydrograph type = Reservoir Peak discharge = 7.753 cfs
Storm frequency = 100 yrs Time to peak = 736 min
Time interval = 2 min Hyd. volume = 35,131 cuft
Inflow hyd. No. = 3 - Post Analysis Point A - High DensityMax. Elevation = 45.66 ft
Reservoir name = Bio Retention Max. Storage = 27,109 cuft
Storage Indication method used. Exfiltration extracted from Outflow.
53
0 120 240 360 480 600 720 840 960 1080
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)
Bio
Hyd. No. 8 -- 100 Year
Hyd No. 8 Hyd No. 3 Total storage used = 27,109 cuft
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Friday, 07 / 12 / 2024
Hyd. No. 9
Post Analysis A- Combined
Hydrograph type = Combine Peak discharge = 8.687 cfs
Storm frequency = 100 yrs Time to peak = 736 min
Time interval = 2 min Hyd. volume = 41,728 cuft
Inflow hyds. = 4, 8 Contrib. drain. area = 0.290 ac
54
0 120 240 360 480 600 720 840 960 1080
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 Analysis A- Combined
Hyd. No. 9 -- 100 Year
Hyd No. 9 Hyd No. 4 Hyd No. 8
Hydraflow Table of Contents SCS-Gordon Road-Clogged.gpw
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Thursday, 07 / 25 / 2024
100 - Year
Summary Report......................................................................................................................... 1
Hydrograph Reports................................................................................................................... 2
Hydrograph No. 1, SCS Runoff, Pre Analysis Point A.............................................................. 2
Hydrograph No. 2, SCS Runoff, Pre Analysis Point B.............................................................. 3
Hydrograph No. 3, SCS Runoff, Post Analysis Point A - High Density..................................... 4
Hydrograph No. 4, SCS Runoff, Post Analysis Point A - Low Density...................................... 5
Hydrograph No. 5, SCS Runoff, Post Analysis Point B............................................................ 6
Hydrograph No. 6, SCS Runoff, Pre Analysis Point C............................................................. 7
Hydrograph No. 7, SCS Runoff, Post Analysis Point C............................................................ 8
Hydrograph No. 8, Reservoir, Bio............................................................................................. 9
Pond Report - Bio Retention.............................................................................................. 10
Hydrograph No. 9, Combine, Post Analysis A- Combined.....................................................12
Hydrograph Summary Report
1
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 10.16 2 724 30,582 ------ ------ ------ Pre Analysis Point A
2 SCS Runoff 12.63 2 724 37,765 ------ ------ ------ Pre Analysis Point B
3 SCS Runoff 21.90 2 724 70,077 ------ ------ ------ Post Analysis Point A - High Density
4 SCS Runoff 2.207 2 724 6,597 ------ ------ ------ Post Analysis Point A - Low Density
5 SCS Runoff 4.947 2 724 14,845 ------ ------ ------ Post Analysis Point B
6 SCS Runoff 33.79 2 724 103,100 ------ ------ ------ Pre Analysis Point C
7 SCS Runoff 36.27 2 724 112,934 ------ ------ ------ Post Analysis Point C
8 Reservoir 15.17 2 728 44,880 3 45.94 30,584 Bio
9 Combine 16.79 2 728 51,477 4, 8 ------ ------ Post Analysis A- Combined
SCS-Gordon Road-Clogged.gpw Return Period: 100 Year Thursday, 07 / 25 / 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 Thursday, 07 / 25 / 2024
Hyd. No. 1
Pre Analysis Point A
Hydrograph type = SCS Runoff Peak discharge = 10.16 cfs
Storm frequency = 100 yrs Time to peak = 12.07 hrs
Time interval = 2 min Hyd. volume = 30,582 cuft
Drainage area = 1.110 ac Curve number = 66*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.820 x 77) + (0.290 x 36)] / 1.110
2
0 2 4 6 8 10 12 14 16 18 20 22 24 26
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 (hrs)
Pre Analysis Point A
Hyd. No. 1 -- 100 Year
Hyd No. 1
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Thursday, 07 / 25 / 2024
Hyd. No. 2
Pre Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 12.63 cfs
Storm frequency = 100 yrs Time to peak = 12.07 hrs
Time interval = 2 min Hyd. volume = 37,765 cuft
Drainage area = 1.660 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.750 x 83) + (0.910 x 36)] / 1.660
3
0 2 4 6 8 10 12 14 16 18 20 22 24 26
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 (hrs)
Pre Analysis Point B
Hyd. No. 2 -- 100 Year
Hyd No. 2
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Thursday, 07 / 25 / 2024
Hyd. No. 3
Post Analysis Point A - High Density
Hydrograph type = SCS Runoff Peak discharge = 21.90 cfs
Storm frequency = 100 yrs Time to peak = 12.07 hrs
Time interval = 2 min Hyd. volume = 70,077 cuft
Drainage area = 1.930 ac Curve number = 84*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(1.190 x 98) + (0.350 x 39) + (0.390 x 80)] / 1.930
4
0 2 4 6 8 10 12 14 16 18 20 22 24
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 (hrs)
Post Analysis Point A - High Density
Hyd. No. 3 -- 100 Year
Hyd No. 3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Thursday, 07 / 25 / 2024
Hyd. No. 4
Post Analysis Point A - Low Density
Hydrograph type = SCS Runoff Peak discharge = 2.207 cfs
Storm frequency = 100 yrs Time to peak = 12.07 hrs
Time interval = 2 min Hyd. volume = 6,597 cuft
Drainage area = 0.290 ac Curve number = 57*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.070 x 98) + (0.030 x 39) + (0.190 x 80)] / 0.290
5
0 2 4 6 8 10 12 14 16 18 20 22 24 26
Q (cfs)
0.00 0.00
1.00 1.00
2.00 2.00
3.00 3.00
Q (cfs)
Time (hrs)
Post Analysis Point A - Low Density
Hyd. No. 4 -- 100 Year
Hyd No. 4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Thursday, 07 / 25 / 2024
Hyd. No. 5
Post Analysis Point B
Hydrograph type = SCS Runoff Peak discharge = 4.947 cfs
Storm frequency = 100 yrs Time to peak = 12.07 hrs
Time interval = 2 min Hyd. volume = 14,845 cuft
Drainage area = 0.560 ac Curve number = 64*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.320 x 80) + (0.230 x 39)] / 0.560
6
0 2 4 6 8 10 12 14 16 18 20 22 24 26
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
Q (cfs)
Time (hrs)
Post Analysis Point B
Hyd. No. 5 -- 100 Year
Hyd No. 5
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Thursday, 07 / 25 / 2024
Hyd. No. 6
Pre Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 33.79 cfs
Storm frequency = 100 yrs Time to peak = 12.07 hrs
Time interval = 2 min Hyd. volume = 103,100 cuft
Drainage area = 3.370 ac Curve number = 72
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
7
0 2 4 6 8 10 12 14 16 18 20 22 24
Q (cfs)
0.00 0.00
5.00 5.00
10.00 10.00
15.00 15.00
20.00 20.00
25.00 25.00
30.00 30.00
35.00 35.00
Q (cfs)
Time (hrs)
Pre Analysis Point C
Hyd. No. 6 -- 100 Year
Hyd No. 6
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Thursday, 07 / 25 / 2024
Hyd. No. 7
Post Analysis Point C
Hydrograph type = SCS Runoff Peak discharge = 36.27 cfs
Storm frequency = 100 yrs Time to peak = 12.07 hrs
Time interval = 2 min Hyd. volume = 112,934 cuft
Drainage area = 3.370 ac Curve number = 78*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = User Time of conc. (Tc) = 5.00 min
Total precip. = 12.70 in Distribution = Type III
Storm duration = 24 hrs Shape factor = 484
* Composite (Area/CN) = [(0.680 x 98) + (2.690 x 69)] / 3.370
8
0 2 4 6 8 10 12 14 16 18 20 22 24
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 (hrs)
Post Analysis Point C
Hyd. No. 7 -- 100 Year
Hyd No. 7
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Thursday, 07 / 25 / 2024
Hyd. No. 8
Bio
Hydrograph type = Reservoir Peak discharge = 15.17 cfs
Storm frequency = 100 yrs Time to peak = 12.13 hrs
Time interval = 2 min Hyd. volume = 44,880 cuft
Inflow hyd. No. = 3 - Post Analysis Point A - High DensityMax. Elevation = 45.94 ft
Reservoir name = Bio Retention Max. Storage = 30,584 cuft
Storage Indication method used.
9
0 2 4 6 8 10 12 14 16 18 20 22 24 26
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 (hrs)
Bio
Hyd. No. 8 -- 100 Year
Hyd No. 8 Hyd No. 3 Total storage used = 30,584 cuft
Pond Report 10
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Thursday, 07 / 25 / 2024
Pond No. 1 - Bio Retention
Pond Data
Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 43.00 ft
Stage / Storage Table
Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft)
0.00 43.00 7,767 0 0
1.00 44.00 9,523 8,629 8,629
2.00 45.00 11,354 10,424 19,053
3.00 46.00 13,243 12,285 31,338
3.50 46.50 14,208 6,861 38,199
Culvert / Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr] [A] [B] [C] [D]
Rise (in)Inactive Inactive 0.00 0.00
Span (in)= 10.00 36.00 0.00 0.00
No. Barrels = 1 1 0 0
Invert El. (ft)= 39.42 44.50 0.00 0.00
Length (ft)= 100.00 0.00 0.00 0.00
Slope (%)= 0.50 0.00 0.00 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)Inactive 20.00 0.00 0.00
Crest El. (ft)= 44.50 45.50 0.00 0.00
Weir Coeff.= 3.33 2.60 3.33 3.33
Weir Type = 1 Broad --- ---
Multi-Stage = Yes No No No
Exfil.(in/hr)= 0.000 (by Contour)
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).
Stage / Storage / Discharge Table
Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total
ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs
0.00 0 43.00 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
0.10 863 43.10 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
0.20 1,726 43.20 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
0.30 2,589 43.30 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
0.40 3,452 43.40 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
0.50 4,315 43.50 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
0.60 5,178 43.60 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
0.70 6,040 43.70 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
0.80 6,903 43.80 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
0.90 7,766 43.90 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
1.00 8,629 44.00 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
1.10 9,672 44.10 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
1.20 10,714 44.20 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
1.30 11,756 44.30 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
1.40 12,799 44.40 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
1.50 13,841 44.50 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
1.60 14,884 44.60 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
1.70 15,926 44.70 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
1.80 16,968 44.80 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
1.90 18,011 44.90 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
2.00 19,053 45.00 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
2.10 20,282 45.10 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
2.20 21,510 45.20 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
2.30 22,739 45.30 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
2.40 23,967 45.40 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
2.50 25,196 45.50 0.00 0.00 --- --- 0.00 0.00 --- --- --- --- 0.000
2.60 26,424 45.60 0.00 0.00 --- --- 0.00 1.64 --- --- --- --- 1.644
2.70 27,653 45.70 0.00 0.00 --- --- 0.00 4.65 --- --- --- --- 4.651
2.80 28,881 45.80 0.00 0.00 --- --- 0.00 8.54 --- --- --- --- 8.544
2.90 30,110 45.90 0.00 0.00 --- --- 0.00 13.15 --- --- --- --- 13.15
3.00 31,338 46.00 0.00 0.00 --- --- 0.00 18.38 --- --- --- --- 18.38
3.05 32,025 46.05 0.00 0.00 --- --- 0.00 21.21 --- --- --- --- 21.21
3.10 32,711 46.10 0.00 0.00 --- --- 0.00 24.17 --- --- --- --- 24.17
3.15 33,397 46.15 0.00 0.00 --- --- 0.00 27.25 --- --- --- --- 27.25
3.20 34,083 46.20 0.00 0.00 --- --- 0.00 30.45 --- --- --- --- 30.45
3.25 34,769 46.25 0.00 0.00 --- --- 0.00 33.77 --- --- --- --- 33.77
3.30 35,455 46.30 0.00 0.00 --- --- 0.00 37.21 --- --- --- --- 37.21
3.35 36,141 46.35 0.00 0.00 --- --- 0.00 40.75 --- --- --- --- 40.75
Continues on next page...
11
Bio Retention
Stage / Storage / Discharge Table
Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total
ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs
3.40 36,827 46.40 0.00 0.00 --- --- 0.00 44.40 --- --- --- --- 44.40
3.45 37,513 46.45 0.00 0.00 --- --- 0.00 48.15 --- --- --- --- 48.15
3.50 38,199 46.50 0.00 0.00 --- --- 0.00 52.00 --- --- --- --- 52.00
...End
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2023 Thursday, 07 / 25 / 2024
Hyd. No. 9
Post Analysis A- Combined
Hydrograph type = Combine Peak discharge = 16.79 cfs
Storm frequency = 100 yrs Time to peak = 12.13 hrs
Time interval = 2 min Hyd. volume = 51,477 cuft
Inflow hyds. = 4, 8 Contrib. drain. area = 0.290 ac
12
0 2 4 6 8 10 12 14 16 18 20 22 24 26
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 (hrs)
Post Analysis A- Combined
Hyd. No. 9 -- 100 Year
Hyd No. 9 Hyd No. 4 Hyd No. 8
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Bioretention Pond Calculations
BIO-RETENTION AREA SIZING DATE
AS-BUILT 28-Mar-24
PROJECT NAME PROJECT NO
Gordon Road 56398
LOCATION BY
WPA
Estimate of Bio-Retention Area and Volume - Basin 1
Drainage Area, (DA) = 1.93 ac
Impervious Area c=0.95 1.19 ac
Pervious Area c= 0.15 0.74 ac
Cc = 0.64
% Impervious = 61.7 %
Temporary Water Quality Pool
Design Storm Rainfall 1.50 in (Typically 1-in)
Runoff Coeff. (Rv = 0.05 + 0.009 (% Imperv.)) = 0.60 ac/ac
Required Volume (design rainfall)(Rv)(DA) = 6,357 cf
Bio-Retention Design
Depth of Storage= 12 in
Surface Area Req.= 6,357 sf
Surface Area Provided= 7,767 sf
Underdrain Design
Soil Mix Hyd. Conductivity, K = 2.0 in/hr = 4.63E-05 fps
Surface Area, A = 7767 sf
Flow through Soil Mix, (K x A) 0.360 cfs
Safety Factor = 3.5
Design Flow, Q = 1.259 cfs
Req'd Underdrain Pipe Diameter, D = 8.68 in
D = 16 [(Q x n) / S 0.5 ]3/8
S = Underdrain Slope = 0.5%
n = 0.011 (smooth PVC)
Number of Pipes Required in Underdrain (per Tbl 5-1, NCDENR BMP Manual)
If D is < # 4" Pipes # 6" Pipes
5.13 2 2
5.95 3 3
6.66 4 4
7.22 5 11.03 5
7.75 6 11.82 6
8.20 7 12.45 7
13.09 8
9.11
10.13
If D is <
7.84
s:\1319\0001\calcs\Bioretention Sizing printed: 7/19/2024 3:49 PM Page 1 of 3
BIO-RETENTION AREA SIZING DATE
13.68 9
14.23 10
Underdrains Provided
Diameter = 6 in
Quantity = 3
Water Quality Volume
Percent Impervious, I 62%
Rv = 0.05 + 0.009(I) 0.60
1.5 inch Runoff volume (Required)
Runoff Volume, S = (Design Rainfall) (Rv) (Drainage Area)
Design Rainfall = 1.5 in
Drainage Area = 1.93 ac
Storage Required =6357 cf
Stage Storage
42.72
Weir Elevation =44.50
31411.00
38273.75
WQV Elevation =
Area (sqft) Inc. Storage (cf)
7767
9523
13243
14208
Elevation (ft)
43
44
46
46.5
45 11354
6862.75
8645
22766
10438.5 10438.50
Total Storage (cf)
8645.00
s:\1319\0001\calcs\Bioretention Sizing printed: 7/19/2024 3:49 PM Page 2 of 3
CONTROL STRUCTURE NAME
CONTROL STRUCTURE
CALCULATED BY
W Altman
5.00 ft
5.00 ft
0.5 ft
44.50 ft
39.42 ft
1.5 ft
6.58 ft
83.22 Cu-ft
0.00 ft^2
0.00 ft^2
0.00 ft^2
0.00 Cu-ft
15.00 inches
0.61 Cu-ft
164.5 Cu-ft
10264.8 lbs
1.15 FS
11804.52 lbs
12483 lbs
0 lbs
92 lbs
12391 lbsTotal Weight of Control Structure (Weight of Concrete Riser - Void Weight of Weirs - Void Weight of Pipes)
Total Weight > Displaced Water Weight? OK If Total Weight < Water Weight (Increase Base Height / Increase Wall Thickness)
Weight of Concrete Riser (Weight = Volume (Vr) * unit weight of concrete 150 lbs/ft^3)
Void Weight of Weirs (Void Weight = Volume (Vw) * unit weight of concrete 150 lbs/ft^3)
Void Weight of Pipes (Void Weight = Volume (Vp) * unit weight of concrete 150 lbs/ft^3)
Weight of Displaced Water (Weight = Volume (Vwat) * unit weight of water 62.4 lbs/ft^3)
Factor of Safety Factor
Resultant Weight of Displaced Water
TOTAL WEIGHT OF THE CONTROL STRUCTURE
Outlet Pipe Diameter (Obtained from Hydrographs)
Void Volume of Pipe (Vp)
DISPLACED VOLUME OF WATER
Volume of Displaced Water (Vwat)(Control Structure Length (L) * Width (W) * Height (H))
Area of Weir 2 (Obtained from Hydrographs)
Area of Weir 3 (Obtained from Hydrographs)
Void Volume of Weirs (Vw)
AREA OF OUTLET PIPE
Height of Resultant Riser (H)(Top of Riser Elevation - Invert Out of Outlet Pipe - Base Height)
Volume of Riser and Base (Vr)
AREA OF CONTROL STRUCTURE WEIRS
Area of Weir 1 (Obtained from Hydrographs)
Top of Riser Elevation (Obtained from Hydrographs)
Invert Out of Outlet Pipe (Obtained from Hydrographs)
Concrete / Non-shrink Grout Base Height (1.5' minumum. Engineer to ensure base is deeper than toe of slope)
DIMENSIONS OF CONTROL STRUCTURE NOTES & FORMULAS
Length of the Riser Exterior (L)
Width of the Riser Exterior (W)
Wall Thickness of the Riser (WT)(Typically 6" (0.5 ft) to 8" (0.67 ft) thickness)
PROJECT NAME
Gordon Road
PROJECT NUMBER
56398
ANTI-BOUYANCY CALCULATIONS
s:\1319\0001\calcs\Bioretention Sizing printed: 7/19/2024 3:49 PM Page 3 of 3
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Drainage Area Calculations
Project: Gordon Road Fire Station Project No.: 56398
Calculated By: A Chaloupecky Date:7/19/2024
Curve Number Value - Pre-Development
CN Ai (Ac)CNi x Ai
77.00 0.82 63.03
36.00 0.29 10.56
83.00 0.00 0.00
1.11 73.588499
∑ (CNi x Ai)
∑ Ai
CN Ai (Ac)CNi x Ai
77.00 0.00 0.00
36.00 0.91 32.87
83.00 0.75 62.02
1.66 94.886387
∑ (CNi x Ai)
∑ Ai
CN Ai (Ac)CNi x Ai
77.00 2.95 227.50
36.00 0.42 15.07
83.00 0.00 0.00
3.37 242.56683
∑ (CNi x Ai)
∑ Ai
Woods (HSG D) - Good
Woods (HSG A) - Fair
Woods (HSG D) - Poor
CN = = 72
CN = = 57
Pre Development C
Category
Pre Development B
Category
Woods (HSG D) - Good
Woods (HSG A) - Fair
Woods (HSG D) - Poor
CN = = 66
Woods (HSG D) - Good
TIMMONS GROUP
Pre Development A
Category
Woods (HSG A) - Fair
Woods (HSG D) - Poor
CN Ai (Ac)CNi x Ai
98.00 1.19 116.22
39.00 0.35 13.53
80.00 0.39 31.49
1.93 161.24
∑ (CNi x Ai)
∑ Ai
CN Ai (Ac)CNi x Ai
98.00 0.07 6.78
39.00 0.19 7.43
80.00 0.03 2.41
0.29 16.62
∑ (CNi x Ai)
∑ Ai
CN Ai (Ac)CNi x Ai
98.00 0.01 1.40
39.00 0.23 8.80
80.00 0.32 25.24
0.56 35.44
∑ (CNi x Ai)
∑ Ai
CN Ai (Ac)CNi x Ai
98.00 0.50 48.85
36.00 0.08 2.75
77.00 1.20 92.08
39.00 0.24 9.50
Open Space/lawn- good condition (HSG D) 80.00 1.36 108.68
3.37 261.85
CN = ∑ (CNi x Ai)= 78
∑ Ai
Impervious
Open Space/lawn- good condition (HSG A)
Woods - good condition (HSG D)
Woods - fair condition (HSG A)
CN = = 64
Post Development C
Category
Post Development B
Category
Impervious
Open Space/lawn- good condition (HSG A)
Open Space/lawn- good condition (HSG D)
Post Development A - Bioretention Pond
Category
Impervious
Open Space/lawn- good condition (HSG D)
CN = = 84
CN = = 57
Open Space/lawn- good condition (HSG A)
Post Development A - Bypass
Category
Impervious
Open Space/lawn- good condition (HSG A)
Open Space/lawn- good condition (HSG D)
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
HGL Calculations
Project: Gordon Road Fire Station Project No.: 56398
Calculated By: A Chaloupecky Date:7/19/2024
Rational C Value - Post-Development- 10 year (Frequency Factor= 1.0)
C Value Ai (Ac)CNi x Ai
0.95 0.13 0.13
0.20 0.01 0.00
0.30 0.01 0.00
0.16 0.13
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 0.14 0.14
0.30 0.00 0.00
0.15 0.14
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 0.18 0.17
0.30 0.02 0.01
0.20 0.18
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 0.13 0.12
0.30 0.00 0.00
0.13 0.12
∑ (Ci x Ai)
∑ Ai
DA - CB 1
Category
Impervious
Open Space/lawn- good condition (HSG A)
TIMMONS GROUP
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.84
DA - CB 2
Impervious
Category
Open Space/lawn- good condition (HSG D)
Cc = = 0.94
DA - CB 3
Category
Open Space/lawn- good condition (HSG D)
Cc = = 0.89
DA - CB 4B
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.95
DA - CB 5B
C Value Ai (Ac)CNi x Ai
0.95 0.34 0.32
0.20 0.01 0.00
0.30 0.01 0.00
0.36 0.33
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 0.15 0.14
0.20 0.02 0.00
0.30 0.07 0.02
0.24 0.16
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 0.12 0.11
0.20 0.15 0.03
0.30 0.02 0.01
0.28 0.15
∑ (Ci x Ai)
∑ Ai
Cc = = 0.69
Category
Impervious
Open Space/lawn- good condition (HSG A)
Open Space/lawn- good condition (HSG D)
Cc = = 0.90
DA - DI 1
Category
Impervious
Open Space/lawn- good condition (HSG A)
Open Space/lawn- good condition (HSG D)
DA - DI 2
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.52
Open Space/lawn- good condition (HSG A)
Project: Gordon Road Fire Station Project No.: 56398
Calculated By: A Chaloupecky Date:
Rational C Value - Post-Development- 25 year (Frequency Factor= 1.1)
C Value C-Value w/Cf of 1.1 Ai (Ac)CNi x Ai
0.95 1.00 0.13 0.13
0.20 0.22 0.01 0.00
0.30 0.33 0.01 0.00
0.16 0.14
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.14 0.14
0.30 0.33 0.00 0.00
0.15 0.14
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.18 0.18
0.30 0.33 0.02 0.01
0.20 0.19
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.13 0.13
0.30 0.33 0.00 0.00
0.13 0.13
∑ (Ci x Ai)
∑ Ai
Cc = = 0.89
Open Space/lawn- good condition (HSG A)
TIMMONS GROUP
DA - CB 1
Category
Impervious
Open Space/lawn- good condition (HSG D)
DA - CB 2
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.99
DA - CB 3
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.94
DA - CB 4B
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 1.00
DA - CB 5B
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.34 0.34
0.20 0.22 0.01 0.00
0.30 0.33 0.01 0.00
0.36 0.34
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.15 0.15
Open Space/lawn- good condition (HSG A) 0.20 0.22 0.02 0.00
0.30 0.33 0.07 0.02
0.24 0.17
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.12 0.12
0.20 0.22 0.15 0.03
0.30 0.33 0.02 0.01
0.28 0.16
∑ (Ci x Ai)
∑ Ai
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.95
Open Space/lawn- good condition (HSG A)
DA - DI 1
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.74
DA - DI 2
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.55
Open Space/lawn- good condition (HSG A)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Thursday, Jul 25 2024
CB1 Gutter Spread
Gutter
Cross Sl, Sx (ft/ft) = 0.015
Cross Sl, Sw (ft/ft) = 0.083
Gutter Width (ft) = 1.00
Invert Elev (ft) = 48.01
Slope (%) = 1.48
N-Value = 0.013
Calculations
Compute by: Known Q
Known Q (cfs) = 2.31
Highlighted
Depth (ft) = 0.22
Q (cfs) = 2.310
Area (sqft) = 0.76
Velocity (ft/s) = 3.03
Wetted Perim (ft) = 10.14
Crit Depth, Yc (ft) = 0.27
Spread Width (ft) = 9.92
EGL (ft) = 0.36
0 5 10 15 20 25 30 35 40
Elev (ft)Depth (ft)Section
47.75 -0.26
48.00 -0.01
48.25 0.24
48.50 0.49
48.75 0.74
49.00 0.99
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Thursday, Jul 25 2024
CB2 Gutter Spread
Gutter
Cross Sl, Sx (ft/ft) = 0.015
Cross Sl, Sw (ft/ft) = 0.083
Gutter Width (ft) = 1.00
Invert Elev (ft) = 47.92
Slope (%) = 0.80
N-Value = 0.013
Calculations
Compute by: Known Q
Known Q (cfs) = 1.62
Highlighted
Depth (ft) = 0.21
Q (cfs) = 1.620
Area (sqft) = 0.73
Velocity (ft/s) = 2.23
Wetted Perim (ft) = 9.82
Crit Depth, Yc (ft) = 0.24
Spread Width (ft) = 9.60
EGL (ft) = 0.29
0 5 10 15 20 25 30 35 40
Elev (ft)Depth (ft)Section
47.00 -0.92
47.50 -0.42
48.00 0.08
48.50 0.58
49.00 1.08
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Thursday, Jul 25 2024
CB3 Gutter Spread
Gutter
Cross Sl, Sx (ft/ft) = 0.022
Cross Sl, Sw (ft/ft) = 0.083
Gutter Width (ft) = 1.00
Invert Elev (ft) = 47.76
Slope (%) = 1.53
N-Value = 0.013
Calculations
Compute by: Known Q
Known Q (cfs) = 2.05
Highlighted
Depth (ft) = 0.22
Q (cfs) = 2.050
Area (sqft) = 0.62
Velocity (ft/s) = 3.32
Wetted Perim (ft) = 7.59
Crit Depth, Yc (ft) = 0.28
Spread Width (ft) = 7.36
EGL (ft) = 0.39
0 5 10 15 20 25 30 35
Elev (ft)Depth (ft)Section
47.00 -0.76
47.50 -0.26
48.00 0.24
48.50 0.74
49.00 1.24
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Thursday, Jul 25 2024
CB4 Gutter Spread
Gutter
Cross Sl, Sx (ft/ft) = 0.012
Cross Sl, Sw (ft/ft) = 0.083
Gutter Width (ft) = 1.00
Invert Elev (ft) = 47.83
Slope (%) = 1.03
N-Value = 0.013
Calculations
Compute by: Known Q
Known Q (cfs) = 1.42
Highlighted
Depth (ft) = 0.19
Q (cfs) = 1.420
Area (sqft) = 0.63
Velocity (ft/s) = 2.25
Wetted Perim (ft) = 10.33
Crit Depth, Yc (ft) = 0.22
Spread Width (ft) = 10.14
EGL (ft) = 0.27
0 5 10 15 20 25 30 35 40 45 50
Elev (ft)Depth (ft)Section
47.00 -0.83
47.50 -0.33
48.00 0.17
48.50 0.67
49.00 1.17
Reach (ft)
Channel Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Thursday, Jul 25 2024
CB5 Gutter Spread
Gutter
Cross Sl, Sx (ft/ft) = 0.010
Cross Sl, Sw (ft/ft) = 0.083
Gutter Width (ft) = 1.00
Invert Elev (ft) = 46.78
Slope (%) = 0.90
N-Value = 0.013
Calculations
Compute by: Known Q
Known Q (cfs) = 3.73
Highlighted
Depth (ft) = 0.24
Q (cfs) = 3.730
Area (sqft) = 1.46
Velocity (ft/s) = 2.55
Wetted Perim (ft) = 17.15
Crit Depth, Yc (ft) = 0.28
Spread Width (ft) = 16.90
EGL (ft) = 0.34
0 5 10 15 20 25 30 35 40 45 50 55
Elev (ft)Depth (ft)Section
46.00 -0.78
46.50 -0.28
47.00 0.22
47.50 0.72
48.00 1.22
Reach (ft)
Project: Gordon Road Fire Station Project No.: 56398
Calculated By: A Chaloupecky Date:
Rational C Value - Post-Development- 100 year (Frequency Factor= 1.25)
C Value C-Value w/Cf of 1.1 Ai (Ac)CNi x Ai
0.95 1.00 0.13 0.13
0.20 0.25 0.01 0.00
0.30 0.38 0.01 0.01
0.16 0.14
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.14 0.14
0.30 0.38 0.00 0.00
0.15 0.14
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.18 0.18
0.30 0.38 0.02 0.01
0.20 0.19
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.13 0.13
0.30 0.38 0.00 0.00
0.13 0.13
∑ (Ci x Ai)
∑ Ai
Cc = = 0.89
Open Space/lawn- good condition (HSG A)
TIMMONS GROUP
DA - CB 1
Category
Impervious
Open Space/lawn- good condition (HSG D)
DA - CB 2
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.99
DA - CB 3
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.94
DA - CB 4B
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 1.00
DA - CB 5B
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.34 0.34
0.20 0.25 0.01 0.00
0.30 0.38 0.01 0.00
0.36 0.34
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.15 0.15
0.20 0.25 0.02 0.00
0.30 0.38 0.07 0.03
0.24 0.18
∑ (Ci x Ai)
∑ Ai
C Value Ai (Ac)CNi x Ai
0.95 1.00 0.12 0.12
0.20 0.25 0.15 0.04
0.30 0.38 0.02 0.01
0.28 0.16
∑ (Ci x Ai)
∑ Ai
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.95
Open Space/lawn- good condition (HSG A)
DA - DI 1
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.75
Open Space/lawn- good condition (HSG A)
DA - DI 2
Category
Impervious
Open Space/lawn- good condition (HSG D)
Cc = = 0.57
Open Space/lawn- good condition (HSG A)
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Rip Rap Calculations
OUTLET PROTECTION DATE
DESIGN
PROJECT NAME PROJECT NO
Gordon Road Fire Station
LOCATION BY
New Hanover County, NC AC
Rip Rap Energy Dissipator RR-SKIMMER
Pipe Diameter:18.00 in
Upper Invert:39.42
Lower Invert:39.00
Pipe Length:83.55 ft *Discharge from Storm Sewers
Pipe Slope:0.50% Discharge: 5.68 cfs
Pipe Material:RCP
Q25 =5.68 cfs Q25/Qfull =0.76
Qfull = 7.46 cfs V/Vfull = 1.10
Vfull = 4.22 fps V = 4.63 fps
Dissipator Dimensions * Zone = 1
Stone Filling Class = A
Entry Width ( 3 X D0 ) = 4.5 ft
Length ( 6 X D0 ) = 9.0 ft
Width (La + D0) = 10.5 ft
Min. Thickness = 12 inches
Stone Diameter (D50)= 3 inches
4.5 10.5
* All units are in feet
** Dissipator pad designed for full flow of pipe
9.0
7/25/2024
56398
Rip Rap Calcs 7/25/2024 Page 1 of 12
OUTLET PROTECTION DATE
DESIGN
PROJECT NAME PROJECT NO
Gordon Road Fire Station
LOCATION BY
New Hanover County, NC AC
Rip Rap Energy Dissipator RR-1
Pipe Diameter:18.00 in
Upper Invert:43.27
Lower Invert:43.00
Pipe Length:33.39 ft *Discharge from Storm Sewers
Pipe Slope:0.81% Discharge: 8.19 cfs
Pipe Material:RCP
Q25 =8.19 cfs Q25/Qfull =0.87
Qfull = 9.46 cfs V/Vfull = 1.12
Vfull = 5.35 fps V = 6.01 fps
Dissipator Dimensions * Zone = 1
Stone Filling Class = A
Entry Width ( 3 X D0 ) = 4.5 ft
Length ( 6 X D0 ) = 9.0 ft
Width (La + D0) = 10.5 ft
Min. Thickness = 12 inches
Stone Diameter (D50)= 3 inches
4.5 10.5
* All units are in feet
** Dissipator pad designed for full flow of pipe
9.0
7/25/2024
56398
Rip Rap Calcs 7/25/2024 Page 2 of 12
OUTLET PROTECTION DATE
DESIGN
PROJECT NAME PROJECT NO
Gordon Road Fire Station
LOCATION BY
New Hanover County, NC AC
Rip Rap Energy Dissipator RR-2
Pipe Diameter:18.00 in
Upper Invert:43.09
Lower Invert:43.00
Pipe Length:18.65 ft *Discharge from Storm Sewers
Pipe Slope:0.48% Discharge: 4.80 cfs
Pipe Material:RCP
Q25 =4.80 cfs Q25/Qfull =0.66
Qfull = 7.31 cfs V/Vfull = 1.07
Vfull = 4.14 fps V = 4.40 fps
Dissipator Dimensions * Zone = 1
Stone Filling Class = A
Entry Width ( 3 X D0 ) = 4.5 ft
Length ( 6 X D0 ) = 9.0 ft
Width (La + D0) = 10.5 ft
Min. Thickness = 12 inches
Stone Diameter (D50)= 3 inches
4.5 10.5
* All units are in feet
** Dissipator pad designed for full flow of pipe
9.0
7/25/2024
56398
Rip Rap Calcs 7/25/2024 Page 3 of 12
OUTLET PROTECTION DATE
DESIGN
PROJECT NAME PROJECT NO
Gordon Road Fire Station
LOCATION BY
New Hanover County, NC AC
Rip Rap Energy Dissipator RR-3
Pipe Diameter:15.00 in
Upper Invert:41.36
Lower Invert:39.83
Pipe Length:110.00 ft *Discharge from Storm Sewers
Pipe Slope:1.39% Discharge: 1.43 cfs
Pipe Material:RCP
Q25 =1.43 cfs Q25/Qfull =0.19
Qfull = 7.63 cfs V/Vfull = 0.75
Vfull = 6.22 fps V = 4.68 fps
Dissipator Dimensions * Zone = 1
Stone Filling Class = A
Entry Width ( 3 X D0 ) = 3.8 ft
Length ( 6 X D0 ) = 7.5 ft
Width (La + D0) = 8.8 ft
Min. Thickness = 12 inches
Stone Diameter (D50)= 3 inches
3.8 8.8
* All units are in feet
** Dissipator pad designed for full flow of pipe
7.5
7/25/2024
56398
Rip Rap Calcs 7/25/2024 Page 4 of 12
OUTLET PROTECTION DATE
DESIGN
PROJECT NAME PROJECT NO
Gordon Road Fire Station
LOCATION BY
New Hanover County, NC AC
Rip Rap Energy Dissipator RR-4
Pipe Diameter:15.00 in
Upper Invert:39.61
Lower Invert:39.15
Pipe Length:92.00 ft *Discharge from Storm Sewers
Pipe Slope:0.50% Discharge: 1.83 cfs
Pipe Material:RCP
Q25 =1.83 cfs Q25/Qfull =0.40
Qfull = 4.57 cfs V/Vfull = 0.94
Vfull = 3.73 fps V = 3.52 fps
Dissipator Dimensions * Zone = 1
Stone Filling Class = A
Entry Width ( 3 X D0 ) = 3.8 ft
Length ( 6 X D0 ) = 7.5 ft
Width (La + D0) = 8.8 ft
Min. Thickness = 12 inches
Stone Diameter (D50)= 3 inches
3.8 8.8
* All units are in feet
** Dissipator pad designed for full flow of pipe
7.5
7/25/2024
56398
Rip Rap Calcs 7/25/2024 Page 5 of 12
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Culvert Calculations
Culvert Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Tuesday, Jul 16 2024
Culvert 10 Yr.
Invert Elev Dn (ft) = 36.93
Pipe Length (ft) = 64.00
Slope (%) = 0.50
Invert Elev Up (ft) = 37.25
Rise (in) = 19.0
Shape = Elliptical
Span (in) = 30.0
No. Barrels = 2
n-Value = 0.012
Culvert Type = Horizontal Ellipse Concrete
Culvert Entrance = Square edge w/headwall (H)
Coeff. K,M,c,Y,k = 0.01, 2, 0.0398, 0.67, 0.5
Embankment
Top Elevation (ft) = 41.32
Top Width (ft) = 46.00
Crest Width (ft) = 0.10
Calculations
Qmin (cfs) = 16.20
Qmax (cfs) = 16.20
Tailwater Elev (ft) = (dc+D)/2
Highlighted
Qtotal (cfs) = 16.20
Qpipe (cfs) = 16.20
Qovertop (cfs) = 0.00
Veloc Dn (ft/s) = 3.12
Veloc Up (ft/s) = 4.45
HGL Dn (ft) = 38.10
HGL Up (ft) = 38.14
Hw Elev (ft) = 38.53
Hw/D (ft) = 0.81
Flow Regime = Inlet Control
Culvert Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Tuesday, Jul 16 2024
Culvert 25 Yr.
Invert Elev Dn (ft) = 36.93
Pipe Length (ft) = 64.00
Slope (%) = 0.50
Invert Elev Up (ft) = 37.25
Rise (in) = 19.0
Shape = Elliptical
Span (in) = 30.0
No. Barrels = 2
n-Value = 0.012
Culvert Type = Horizontal Ellipse Concrete
Culvert Entrance = Square edge w/headwall (H)
Coeff. K,M,c,Y,k = 0.01, 2, 0.0398, 0.67, 0.5
Embankment
Top Elevation (ft) = 41.32
Top Width (ft) = 46.00
Crest Width (ft) = 0.10
Calculations
Qmin (cfs) = 18.53
Qmax (cfs) = 18.53
Tailwater Elev (ft) = (dc+D)/2
Highlighted
Qtotal (cfs) = 18.53
Qpipe (cfs) = 18.53
Qovertop (cfs) = 0.00
Veloc Dn (ft/s) = 3.57
Veloc Up (ft/s) = 5.09
HGL Dn (ft) = 38.10
HGL Up (ft) = 38.14
Hw Elev (ft) = 38.69
Hw/D (ft) = 0.91
Flow Regime = Inlet Control
Culvert Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Tuesday, Jul 16 2024
DWLT
Invert Elev Dn (ft) = 41.85
Pipe Length (ft) = 110.00
Slope (%) = 2.13
Invert Elev Up (ft) = 44.19
Rise (in) = 15.0
Shape = Circular
Span (in) = 15.0
No. Barrels = 1
n-Value = 0.012
Culvert Type = Circular Concrete
Culvert Entrance = Square edge w/headwall (C)
Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5
Embankment
Top Elevation (ft) = 46.00
Top Width (ft) = 90.00
Crest Width (ft) = 0.10
Calculations
Qmin (cfs) = 1.43
Qmax (cfs) = 1.43
Tailwater Elev (ft) = (dc+D)/2
Highlighted
Qtotal (cfs) = 1.43
Qpipe (cfs) = 1.43
Qovertop (cfs) = 0.00
Veloc Dn (ft/s) = 1.59
Veloc Up (ft/s) = 3.36
HGL Dn (ft) = 42.71
HGL Up (ft) = 44.66
Hw Elev (ft) = 44.84
Hw/D (ft) = 0.52
Flow Regime = Inlet Control
Culvert Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Tuesday, Jul 16 2024
DWRT
Invert Elev Dn (ft) = 39.14
Pipe Length (ft) = 95.00
Slope (%) = 1.66
Invert Elev Up (ft) = 40.72
Rise (in) = 15.0
Shape = Circular
Span (in) = 15.0
No. Barrels = 1
n-Value = 0.012
Culvert Type = Circular Concrete
Culvert Entrance = Square edge w/headwall (C)
Coeff. K,M,c,Y,k = 0.0098, 2, 0.0398, 0.67, 0.5
Embankment
Top Elevation (ft) = 43.00
Top Width (ft) = 80.00
Crest Width (ft) = 0.10
Calculations
Qmin (cfs) = 1.83
Qmax (cfs) = 1.83
Tailwater Elev (ft) = (dc+D)/2
Highlighted
Qtotal (cfs) = 1.83
Qpipe (cfs) = 1.83
Qovertop (cfs) = 0.00
Veloc Dn (ft/s) = 1.95
Veloc Up (ft/s) = 3.63
HGL Dn (ft) = 40.03
HGL Up (ft) = 41.26
Hw Elev (ft) = 41.47
Hw/D (ft) = 0.60
Flow Regime = Inlet Control
Culvert Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Tuesday, Jul 16 2024
Culvert 100 Yr.
Invert Elev Dn (ft) = 36.93
Pipe Length (ft) = 64.00
Slope (%) = 0.50
Invert Elev Up (ft) = 37.25
Rise (in) = 19.0
Shape = Elliptical
Span (in) = 30.0
No. Barrels = 2
n-Value = 0.012
Culvert Type = Horizontal Ellipse Concrete
Culvert Entrance = Square edge w/headwall (H)
Coeff. K,M,c,Y,k = 0.01, 2, 0.0398, 0.67, 0.5
Embankment
Top Elevation (ft) = 41.32
Top Width (ft) = 46.00
Crest Width (ft) = 0.10
Calculations
Qmin (cfs) = 22.10
Qmax (cfs) = 22.10
Tailwater Elev (ft) = (dc+D)/2
Highlighted
Qtotal (cfs) = 22.10
Qpipe (cfs) = 22.10
Qovertop (cfs) = 0.00
Veloc Dn (ft/s) = 4.09
Veloc Up (ft/s) = 6.08
HGL Dn (ft) = 38.13
HGL Up (ft) = 38.14
Hw Elev (ft) = 38.92
Hw/D (ft) = 1.06
Flow Regime = Inlet Control
Culvert Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Tuesday, Jul 16 2024
Culvert 500 Yr.
Invert Elev Dn (ft) = 36.93
Pipe Length (ft) = 64.00
Slope (%) = 0.50
Invert Elev Up (ft) = 37.25
Rise (in) = 19.0
Shape = Elliptical
Span (in) = 30.0
No. Barrels = 2
n-Value = 0.012
Culvert Type = Horizontal Ellipse Concrete
Culvert Entrance = Square edge w/headwall (H)
Coeff. K,M,c,Y,k = 0.01, 2, 0.0398, 0.67, 0.5
Embankment
Top Elevation (ft) = 41.32
Top Width (ft) = 46.00
Crest Width (ft) = 0.10
Calculations
Qmin (cfs) = 26.34
Qmax (cfs) = 26.34
Tailwater Elev (ft) = (dc+D)/2
Highlighted
Qtotal (cfs) = 26.34
Qpipe (cfs) = 26.34
Qovertop (cfs) = 0.00
Veloc Dn (ft/s) = 4.87
Veloc Up (ft/s) = 6.05
HGL Dn (ft) = 38.20
HGL Up (ft) = 38.26
Hw Elev (ft) = 39.05
Hw/D (ft) = 1.13
Flow Regime = Inlet Control
Culvert Report
Hydraflow Express Extension for Autodesk® Civil 3D® by Autodesk, Inc. Tuesday, Jul 16 2024
Culvert Overtopping
Invert Elev Dn (ft) = 36.93
Pipe Length (ft) = 64.00
Slope (%) = 0.50
Invert Elev Up (ft) = 37.25
Rise (in) = 19.0
Shape = Elliptical
Span (in) = 30.0
No. Barrels = 2
n-Value = 0.012
Culvert Type = Horizontal Ellipse Concrete
Culvert Entrance = Square edge w/headwall (H)
Coeff. K,M,c,Y,k = 0.01, 2, 0.0398, 0.67, 0.5
Embankment
Top Elevation (ft) = 41.32
Top Width (ft) = 46.00
Crest Width (ft) = 0.10
Calculations
Qmin (cfs) = 54.25
Qmax (cfs) = 54.25
Tailwater Elev (ft) = (dc+D)/2
Highlighted
Qtotal (cfs) = 54.25
Qpipe (cfs) = 54.25
Qovertop (cfs) = 0.00
Veloc Dn (ft/s) = 9.09
Veloc Up (ft/s) = 8.73
HGL Dn (ft) = 38.39
HGL Up (ft) = 39.24
Hw Elev (ft) = 41.34
Hw/D (ft) = 2.58
Flow Regime = Inlet Control
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Erosion Control Calculations
1
Area (A) =0.32 (Acres)
Coef. (C) = 0.35 (Dimensionless)
Inte. (I) =9.70 (in/hr)
Flow (Q10) =1.1 (cfs)
Line channel with:6 " rip-rap (Assume 6" even if using grass)
Manning n =0.030 (Dimensionless) Ditch Length = 446 LF
Slope = 0.013 (ft/ft) Highest Elevation = 44
Z Required = 0.19 Ratio Lowest Elevation = 38
Side Slope (M) =3 :1
Flow Depth (Y) =1.00 ft 12.0 in
Bottom Width (B) =0.00 ft 0.0 in
Freeboard = 0.50 ft 6.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.84 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
LB/SF
Jute Net 0.45 LB/SF
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II (18"@30"THK) 7.50 P300 8.00
New A = 3.00 SF
New P = 6.32 Wetted perimeter
New R = 0.47 Hydraulic radius
Z Actual =1.82 Must be greater than z required=>0.19 Okay
New V = 3.50 fps
Liner:1.55 LB/SF > 0.84 LB/SF Okay
Min. Ditch Depth = 1.5 ft
3
1
Side Slope
3:1
*RED IS USER INPUT
Ditch Liner
Curled Mat
Min. Ditch Depth (ft) Bottom Width (ft) Flow Depth (ft) Top Width (ft)
1.50 0.00 1.00 9
Ditch Geometry
Variable Quantities (Ditch Width & Depth)
Compute Tractive Force
General Lining North American
Green Lining
Determine If Z Actual Is Greater Than Z Required
Minimum Design Geometry
Curled Mat
Top Width = 9 ft
Flow Depth (Y) = 1 ft
Bottom Width (B) = 0 ft
Known Quantities
DITCH NAME PROJECT NAME
Gordon Road Fire Station
CALCULATED BY PROJECT NUMBER
Andrew Chaloupecky 56389
Drainage Ditch Design (Velocity Constraint)
TEMPORARY DIVERSION DITCH: 1
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Watershed Data
LATEST REVISION: 7/30/2024 6:09 PM
CALCULATED BY
Andrew Chaloupecky
Velocity =3.50 fps From Fig. 8.06.c:ZONE =1
Top Width =9 ft
Ditch Area = 3 sf Rip Rap Class = A
Equivalent Pipe Diameter = 23.45 in Apron Thickness = 12 in
Equivalent Pipe Diameter =24 in Apron Length = 8.0 ft
Apron Width = Top Width.= 9.0 ft
From Fig. 8.06.e:
Ditch Name: 1
PROJECT NAME
Gordon Road Fire Station
PROJECT NUMBER
56389
Ditch Outlet Protection (NCDOT Method)
LATEST REVISION: 7/30/2024 6:09 PM
2
Area (A) =0.41 (Acres)
Coef. (C) = 0.35 (Dimensionless)
Inte. (I) =9.70 (in/hr)
Flow (Q10) =1.4 (cfs)
Line channel with:6 " rip-rap (Assume 6" even if using grass)
Manning n =0.030 (Dimensionless) Ditch Length = 308 LF
Slope = 0.009 (ft/ft) Highest Elevation = 40.9
Z Required = 0.29 Ratio Lowest Elevation = 38
Side Slope (M) =3 :1
Flow Depth (Y) =1.00 ft 12.0 in
Bottom Width (B) =0.00 ft 0.0 in
Freeboard = 0.50 ft 6.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.59 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
LB/SF
Jute Net 0.45 LB/SF
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II (18"@30"THK) 7.50 P300 8.00
New A = 3.00 SF
New P = 6.32 Wetted perimeter
New R = 0.47 Hydraulic radius
Z Actual =1.82 Must be greater than z required=>0.29 Okay
New V = 2.93 fps
Liner:1.55 LB/SF > 0.59 LB/SF Okay
Min. Ditch Depth = 1.5 ft
3
1
Side Slope
3:1
*RED IS USER INPUT
Ditch Liner
Curled Mat
Min. Ditch Depth (ft) Bottom Width (ft) Flow Depth (ft) Top Width (ft)
1.50 0.00 1.00 9
Ditch Geometry
Variable Quantities (Ditch Width & Depth)
Compute Tractive Force
General Lining North American
Green Lining
Determine If Z Actual Is Greater Than Z Required
Minimum Design Geometry
Curled Mat
Top Width = 9 ft
Flow Depth (Y) = 1 ft
Bottom Width (B) = 0 ft
Known Quantities
DITCH NAME PROJECT NAME
Gordon Road Fire Station
CALCULATED BY PROJECT NUMBER
Andrew Chaloupecky 56389
Drainage Ditch Design (Velocity Constraint)
TEMPORARY DIVERSION DITCH: 2
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Watershed Data
LATEST REVISION: 7/30/2024 6:09 PM
CALCULATED BY
Andrew Chaloupecky
Velocity =2.93 fps From Fig. 8.06.c:ZONE =1
Top Width =9 ft
Ditch Area = 3 sf Rip Rap Class = A
Equivalent Pipe Diameter = 23.45 in Apron Thickness = 12 in
Equivalent Pipe Diameter =24 in Apron Length = 8.0 ft
Apron Width = Top Width.= 9.0 ft
From Fig. 8.06.e:
Ditch Name: 2
PROJECT NAME
Gordon Road Fire Station
PROJECT NUMBER
56389
Ditch Outlet Protection (NCDOT Method)
LATEST REVISION: 7/30/2024 6:09 PM
3
Area (A) =0.50 (Acres)
Coef. (C) = 0.35 (Dimensionless)
Inte. (I) =9.70 (in/hr)
Flow (Q10) =1.7 (cfs)
Line channel with:6 " rip-rap (Assume 6" even if using grass)
Manning n =0.030 (Dimensionless) Ditch Length = 403 LF
Slope = 0.018 (ft/ft) Highest Elevation = 45.1
Z Required = 0.26 Ratio Lowest Elevation = 38
Side Slope (M) =3 :1
Flow Depth (Y) =1.00 ft 12.0 in
Bottom Width (B) =0.00 ft 0.0 in
Freeboard = 0.50 ft 6.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 1.10 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
LB/SF
Jute Net 0.45 LB/SF
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II (18"@30"THK) 7.50 P300 8.00
New A = 3.00 SF
New P = 6.32 Wetted perimeter
New R = 0.47 Hydraulic radius
Z Actual =1.82 Must be greater than z required=>0.26 Okay
New V = 4.01 fps
Liner:1.55 LB/SF > 1.1 LB/SF Okay
Min. Ditch Depth = 1.5 ft
3
1
Side Slope
3:1
*RED IS USER INPUT
Ditch Liner
Curled Mat
Min. Ditch Depth (ft) Bottom Width (ft) Flow Depth (ft) Top Width (ft)
1.50 0.00 1.00 9
Ditch Geometry
Variable Quantities (Ditch Width & Depth)
Compute Tractive Force
General Lining North American
Green Lining
Determine If Z Actual Is Greater Than Z Required
Minimum Design Geometry
Curled Mat
Top Width = 9 ft
Flow Depth (Y) = 1 ft
Bottom Width (B) = 0 ft
Known Quantities
DITCH NAME PROJECT NAME
Gordon Road Fire Station
CALCULATED BY PROJECT NUMBER
Andrew Chaloupecky 56389
Drainage Ditch Design (Velocity Constraint)
TEMPORARY DIVERSION DITCH: 3
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Watershed Data
LATEST REVISION: 7/30/2024 6:09 PM
CALCULATED BY
Andrew Chaloupecky
Velocity =4.01 fps From Fig. 8.06.c:ZONE =1
Top Width =9 ft
Ditch Area = 3 sf Rip Rap Class = A
Equivalent Pipe Diameter = 23.45 in Apron Thickness = 12 in
Equivalent Pipe Diameter =24 in Apron Length = 8.0 ft
Apron Width = Top Width.= 9.0 ft
From Fig. 8.06.e:
Ditch Name: 3
PROJECT NAME
Gordon Road Fire Station
PROJECT NUMBER
56389
Ditch Outlet Protection (NCDOT Method)
LATEST REVISION: 7/30/2024 6:09 PM
4
Area (A) =0.24 (Acres)
Coef. (C) = 0.35 (Dimensionless)
Inte. (I) =9.70 (in/hr)
Flow (Q10) =0.8 (cfs)
Line channel with:6 " rip-rap (Assume 6" even if using grass)
Manning n =0.030 (Dimensionless) Ditch Length = 297 LF
Slope = 0.013 (ft/ft) Highest Elevation = 42
Z Required = 0.14 Ratio Lowest Elevation = 38
Side Slope (M) =3 :1
Flow Depth (Y) =1.00 ft 12.0 in
Bottom Width (B) =0.00 ft 0.0 in
Freeboard = 0.50 ft 6.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.84 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
LB/SF
Jute Net 0.45 LB/SF
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II (18"@30"THK) 7.50 P300 8.00
New A = 3.00 SF
New P = 6.32 Wetted perimeter
New R = 0.47 Hydraulic radius
Z Actual =1.82 Must be greater than z required=>0.14 Okay
New V = 3.51 fps
Liner:1.55 LB/SF > 0.85 LB/SF Okay
Min. Ditch Depth = 1.5 ft
3
1
Side Slope
3:1
*RED IS USER INPUT
Ditch Liner
Curled Mat
Min. Ditch Depth (ft) Bottom Width (ft) Flow Depth (ft) Top Width (ft)
1.50 0.00 1.00 9
Ditch Geometry
Variable Quantities (Ditch Width & Depth)
Compute Tractive Force
General Lining North American
Green Lining
Determine If Z Actual Is Greater Than Z Required
Minimum Design Geometry
Curled Mat
Top Width = 9 ft
Flow Depth (Y) = 1 ft
Bottom Width (B) = 0 ft
Known Quantities
DITCH NAME PROJECT NAME
Gordon Road Fire Station
CALCULATED BY PROJECT NUMBER
Andrew Chaloupecky 56389
Drainage Ditch Design (Velocity Constraint)
TEMPORARY DIVERSION DITCH: 4
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Watershed Data
LATEST REVISION: 7/30/2024 6:09 PM
CALCULATED BY
Andrew Chaloupecky
Velocity =3.51 fps From Fig. 8.06.c:ZONE =1
Top Width =9 ft
Ditch Area = 3 sf Rip Rap Class = A
Equivalent Pipe Diameter = 23.45 in Apron Thickness = 12 in
Equivalent Pipe Diameter =24 in Apron Length = 8.0 ft
Apron Width = Top Width.= 9.0 ft
From Fig. 8.06.e:
Ditch Name: 4
PROJECT NAME
Gordon Road Fire Station
PROJECT NUMBER
56389
Ditch Outlet Protection (NCDOT Method)
LATEST REVISION: 7/30/2024 6:09 PM
5
Area (A) =0.60 (Acres)
Coef. (C) = 0.35 (Dimensionless)
Inte. (I) =9.70 (in/hr)
Flow (Q10) =2.0 (cfs)
Line channel with:6 " rip-rap (Assume 6" even if using grass)
Manning n =0.030 (Dimensionless) Ditch Length = 211 LF
Slope = 0.007 (ft/ft) Highest Elevation = 44.5
Z Required = 0.49 Ratio Lowest Elevation = 43
Side Slope (M) =3 :1
Flow Depth (Y) =1.00 ft 12.0 in
Bottom Width (B) =0.00 ft 0.0 in
Freeboard = 0.50 ft 6.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.44 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
LB/SF
Jute Net 0.45 LB/SF
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II (18"@30"THK) 7.50 P300 8.00
New A = 3.00 SF
New P = 6.32 Wetted perimeter
New R = 0.47 Hydraulic radius
Z Actual =1.82 Must be greater than z required=>0.49 Okay
New V = 2.55 fps
Liner:0.45 LB/SF > 0.45 LB/SF Okay
Min. Ditch Depth = 1.5 ft
3
1
Side Slope
3:1
*RED IS USER INPUT
0.00 1.00 9
TEMPORARY DIVERSION DITCH: 5
Top Width = 9 ft
Variable Quantities (Ditch Width & Depth)
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Watershed Data
Known Quantities
Compute Tractive Force
Drainage Ditch Design (Velocity Constraint)
PROJECT NAME
PROJECT NUMBER
56389
DITCH NAME
CALCULATED BY
Andrew Chaloupecky
Gordon Road Fire Station
Ditch Liner
Jute Net
Jute Net
General Lining North American
Green Lining
Determine If Z Actual Is Greater Than Z Required
Minimum Design Geometry
Min. Ditch Depth (ft)
1.50
Bottom Width (ft)
Flow Depth (Y) = 1 ft
Ditch Geometry
Bottom Width (B) = 0 ft
Top Width (ft)Flow Depth (ft)
LATEST REVISION: 7/30/2024 6:09 PM
CALCULATED BY
Andrew Chaloupecky
Velocity =2.55 fps From Fig. 8.06.c:ZONE =1
Top Width =9 ft
Ditch Area = 3 sf Rip Rap Class = A
Equivalent Pipe Diameter = 23.45 in Apron Thickness = 12 in
Equivalent Pipe Diameter =24 in Apron Length = 8.0 ft
Apron Width = Top Width.= 9.0 ft
From Fig. 8.06.e:
Ditch Name: 5
PROJECT NAME
Gordon Road Fire Station
PROJECT NUMBER
56389
Ditch Outlet Protection (NCDOT Method)
LATEST REVISION: 7/30/2024 6:09 PM
6
Area (A) =0.50 (Acres)
Coef. (C) = 0.35 (Dimensionless)
Inte. (I) =9.70 (in/hr)
Flow (Q10) =1.7 (cfs)
Line channel with:6 " rip-rap (Assume 6" even if using grass)
Manning n =0.030 (Dimensionless) Ditch Length = 312 LF
Slope = 0.005 (ft/ft) Highest Elevation = 44.5
Z Required = 0.49 Ratio Lowest Elevation = 43
Side Slope (M) =3 :1
Flow Depth (Y) =1.00 ft 12.0 in
Bottom Width (B) =0.00 ft 0.0 in
Freeboard = 0.50 ft 6.0 in
T=YxDxS Y = Weight of water (62.4 LB/CUFT)
T = 0.30 LB/SF D=Depth of flow in channel (ft)
S=Slope of channel (ft/ft)
LB/SF
Jute Net 0.45 LB/SF
Curled Mat 1.55 S75 1.55
Class A (4"@9"THK) 2.00 S150 1.75
Class B (8"@18"THK) 3.50 SC150 2.10
Class I (12"@22"THK) 5.00 C125 2.25
Class II (18"@30"THK) 7.50 P300 8.00
New A = 3.00 SF
New P = 6.32 Wetted perimeter
New R = 0.47 Hydraulic radius
Z Actual =1.82 Must be greater than z required=>0.49 Okay
New V = 2.09 fps
Liner:0.45 LB/SF > 0.3 LB/SF Okay
Min. Ditch Depth = 1.5 ft
3
1
Side Slope
3:1
*RED IS USER INPUT
Ditch Liner
Jute Net
Min. Ditch Depth (ft) Bottom Width (ft) Flow Depth (ft) Top Width (ft)
1.50 0.00 1.00 9
Ditch Geometry
Variable Quantities (Ditch Width & Depth)
Compute Tractive Force
General Lining North American
Green Lining
Determine If Z Actual Is Greater Than Z Required
Minimum Design Geometry
Jute Net
Top Width = 9 ft
Flow Depth (Y) = 1 ft
Bottom Width (B) = 0 ft
Known Quantities
DITCH NAME PROJECT NAME
Gordon Road Fire Station
CALCULATED BY PROJECT NUMBER
Andrew Chaloupecky 56389
Drainage Ditch Design (Velocity Constraint)
TEMPORARY DIVERSION DITCH: 6
This worksheet is designed to determine channel lining based on flow and ditch geometry (base width, side
slope, & channel slope). This program determines depth of flow, velocity and tractive force assuming n=0.03
for grass or rip rap (n can be varied if desired). (Vary depth until z actual equals z required; v & t will be
correct; select appropriate lining based on tractive force)
Watershed Data
LATEST REVISION: 7/30/2024 6:09 PM
CALCULATED BY
Andrew Chaloupecky
Velocity =2.09 fps From Fig. 8.06.c:ZONE =1
Top Width =9 ft
Ditch Area = 3 sf Rip Rap Class = A
Equivalent Pipe Diameter = 23.45 in Apron Thickness = 12 in
Equivalent Pipe Diameter =24 in Apron Length = 8.0 ft
Apron Width = Top Width.= 9.0 ft
From Fig. 8.06.e:
Ditch Name: 6
PROJECT NAME
Gordon Road Fire Station
PROJECT NUMBER
56389
Ditch Outlet Protection (NCDOT Method)
LATEST REVISION: 7/30/2024 6:09 PM
LENGTH DA
ACCUM.
DA I10 Q10 SLOPE V SHEAR
FLOW
DEPTH
FLOW
AREA Wp R
SWALE
DEPTH
SIDE
SLOPE
(FT) (AC) (AC) (IN/HR) (CFS) (%) (FT/S) (PSF) (FT) (FT^2) (FT) (FT) (IN) (H:V)
DITCH 1 265 0.51 2.44 0.64 9.70 15.15 2.87% 0.033 4.76 1.86 1.04 3.25 6.58 0.49 24 3:1 GRASS
DITCH 2 280 0.44 0.40 9.70 1.71 0.90% 0.037 1.65 0.34 0.60 1.08 3.79 0.28 24 3:1 GRASS
DITCH 3 385 0.53 0.63 9.70 3.24 1.61% 0.037 2.42 0.69 0.69 1.43 4.36 0.33 24 3:1 GRASS
DITCH 4 280 0.37 0.49 9.70 1.76 0.88% 0.037 1.65 0.33 0.61 1.12 3.86 0.29 24 3:1 GRASS
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
0.50 9.70 0.00 #DIV/0! 0.00 #DIV/0! 24 3:1 NAG P550
NAME
PERMANENT CHANNEL SCHEDULE
(Chapter 8.05 of the NCDEQ E&SC Planning and Design Manual)
C N VALUE
PERMANENT
LINING
2
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Section 4: Stormwater Compliance
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Pre/Post Stormwater Maps
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PROPOSED BUILDING
14,461 SF
REFER TO R-SERIES FOR
DRIVEWAY PLANS
10'x70' SIGHT VISIBILITY
TRIANGLE
10'x70' SIGHT VISIBILITY
TRIANGLE
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LOW DENSITY
DRAINAGE AREA
HIGH DENSITY
DRAINAGE AREA
Project No.
56398
Date:
Sheet No.
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Drawn by:
Checked by:
Revisions:
ALL NOTES APPLY TO ALL DRAWINGS AND ALL TRADES. IT IS THE RESPONSIBILITY OF ALL CONTRACTORS AND
TRADES TO COORDINATE THE INSTALLATION OF THEIR WORK WITH THE INSTALLATION OF WORK BY ALL OTHER
CONTRACTORS AND TRADES. THE REQUIREMENTS OF THE DRAWINGS, GENERAL REQUIREMENTS AND ALL ITEMS
OF THE CONTRACT DOCUMENTS ARE EQUALLY BINDING ON ALL CONTRACTORS AND TRADES. EACH
CONTRACTOR IS REQUIRED TO MAINTAIN FULL SETS OF THE CONTRACT DOCUMENTS FOR HIS EMPLOYEES USE
ON THE PROJECT TO ASSURE THAT ALL WORK IS PROPERLY COORDINATED AND INSTALLED WITH THE WORK OF
OTHER CONTRACTORS AND TRADES.
WHENEVER THERE ARE DISCREPANCIES BETWEEN DRAWINGS, OR BETWEEN THE DRAWINGS AND
SPECIFICATIONS, OR CONFLICTS WITHIN THE SPECIFICATIONS AND/OR DRAWINGS, AND SUCH DISCREPANCY IS
NOT CALLED TO THE ARCHITECT'S ATTENTION IN TIME TO PERMIT CLARIFICATION BY ADDENDUM, THE
CONTRACTOR SHALL BASE HIS BID UPON PROVIDING THE BETTER QUALITY OR GREATER OF WORK OR MATERIAL
CALLED FOR, SHALL SUBMIT A WRITTEN STATEMENT WITH HIS PROPOSAL NOTING SUCH DISCREPANCIES, AND
SHALL SO FURNISH AND INSTALL SUCH BETTER QUALITY OR GREATER QUANTITY UNLESS OTHERWISE ORDERED
IN WRITING.
GENERAL NOTE
03/29/2024
A CHALOUPECKY
W ALTMAN
Addendum 02
5/10/2024
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5410 Trinity Road, Suite 102Raleigh, NC 27607TEL 919.866.4951
FAX 919.859.5663
www.timmons.com
YOUR VISION ACHIEVED THROUGH OURS.
VIRGINIA NORTH CAROLINA
Site Development Residential Infrastructure Technology
THIS DRAWING PREPARED AT THE
RALEIGH OFFICE
56398-333
North Carolina License No. C-1652
2nd Submittal NHC
8/02/2024
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SCALE 1"=80'
160'80'0
SCALE 1"=80'
160'80'
PRE-DEVELOPED SITE
LEGEND
IMPERVIOUS
AREA
PRE DEVELOPMENT ONSITE IMPERVIOUS SURFACES = 0.00 ACRES
POST DEVELOPMENT ONSITE IMPERVIOUS SURFACES = 1.28 ACRES
POST DEVELOPMENT OFFSITE IMPERVIOUS SURFACES = 0.50 ACRES
POST DEVELOPMENT FUTURE OFFSITE IMPERVIOUS SURFACES = 0.18 ACRES
IMPERVIOUS AREA BEING TREATED BY BIORETENTION CELL = 1.19 ACRES
STORMWATER QUALITY CALCULATIONS
POST-DEVELOPED SITE
ANALYSIS POINT A
DRAINAGE
AREA
(Acres)
(CN)
PRE-DEVELOPMENT 1.11
Q1
66 1.13
POST-DEVELOPMENT
A1 (BIO RETENTION)1.93 84 4.92
POST-DEVELOPMENT
A2 (BYPASS)
POST-DEVELOPMENT
A (COMBINED)
0.29 57 0.12
2.22 0.12
Q2
1.81
6.48
0.25
0.25
Q10
4.29
11.49
0.79
3.77
C4.3
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ANALYSIS POINT B
DRAINAGE
AREA
(Acres)
(CN)
PRE-DEVELOPMENT 1.66
Q1
57 0.69
Q2
1.41
Q10
4.51
POST-DEVELOPMENT 0.56 64 0.49 0.81 2.02
Q25
6.25
15.07
1.25
5.37
Q100
10.16
21.90
2.21
8.69
Q25
7.13
Q100
12.63
2.99 4.95
ANALYSIS POINT C
DRAINAGE
AREA
(Acres)
(CN)
PRE-DEVELOPMENT 3.37
Q1
72 5.02
Q2
7.37
Q10
15.54
POST-DEVELOPMENT 3.37 78 6.75 9.34 17.92
Q25
21.72
Q100
33.79
24.20 36.27
Gordon Road Fire Station
Wilmington, NC
Project Number: 56398
www.timmons.com
Nutrient Loading
Project: Gordon Road Fire Station Project No.: 56398
Calculated By: Andrew Chaloupecky Date: 06/20/2024
NITROGEN EXPORT WORKSHEET
Apportioned Open Space Calculation = (New Impervious Area/Total Impervious Area) X (Remaining Open Space)
** Apportioned Open Space Calculation** = (1.28 ac - 0 ac) / 1.28 ac X (1.49 ac) = 1.49 ac
Final Impervious 1.28
Existing Impervious 0.00
Total Drainage Area 2.77
Final Open Space 1.49
Undisturbed Riparian Buffer Area 0.00
(From Section 3.1.2.1 City of Raleigh Stormwater Manual)
Site Area
(ac)
TN Export
By Use
(lbs/yr)
TN Export
From Site
(lbs/ac/yr)
0.00 0.00
1.49 1.79
1.28 27.14
2.77 28.92
10.44
Site Area
(ac)
TN Export
By Use
(lbs/yr)
TN Export
From Site
(lbs/ac/yr)
0.00 0.00
0.74 0.89
1.19 25.23
1.93 26.12
BMP Proposed Area Treated by
BMP (ac)
Treated TN
Export
TN Export
(lbs/ac/yr)
Bioretention 1.93 26.12
6.67
(Site Export -3.6) X (Site Area) X (30 YEARS) = Pounds of TN Exported
(Site Export -3.6) X (Site Area) X ($655.80) = Buy Down
TIMMONS GROUP
POST DEVELOPMENT NITROGEN LOADING
Type of Land Cover TN Export Coeff.
(lbs/ac/yr)
PERMANENTLY PRESERVED UNDISTURBED OPEN SPACE
RIPARIAN BUFFER AREA 0.60
APPORTIONED OPEN SPACE 1.20
NEW IMPERVIOUS SURFACES 21.20
Total
Average for Site
TN EXPORT TREATED BY BMP (ONSITE & OFFSITE)
Type of Land Cover TN Export Coeff.
(lbs/ac/yr)
PERMANENTLY PRESERVED UNDISTURBED
OPEN SPACE 0.60
PERMANENTLY PRESERVED MANAGED
OPEN SPACE 1.20
IMPERVIOUS SURFACES 21.20
Total
POST DEVELOPMENT NITROGEN LOADING AFTER BMP TREATMENT
TN Reduction (%) TN Reduction (lbs/yr)
40%10.45
Total (TN EXPORT -TN REDUCTION) / SITE AREA
ESTIMATED BUY DOWN
(6.67 - 3.6) X (2.77) X ($655.80)7,233$
POUNDS OF NITROGEN EXPORTED
(6.67 - 3.6) X (2.77) X (30 YEARS)255