SW3230701_Design Calculations_20230706

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SANDERS
WI° ENGINEERING
STEWARTS GROVE
Stormwater Impact Analysis & Design of
Stormwater Control Measures
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WINGATE, NC
June 21, 2023
Prepared By:
Sanders Engineering, PLLC
180 Perry Road • Southern Pines, NC 28387 • P: (910) 725-1020 • License44 P-2463
www . sandersengineers . com
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TABLE OF CONTENTS
1. GENERAL DESCRIPTION
2. CALCULATION METHODOLOGY
3. SUMMARY OF RESULTS
4. MISCELLANEOUS SITE INFORMATION
5. PRE-DEVELOPMENT HYDROLOGIC CALCULATIONS
6. POST-DEVELOPMENT HYDROLOGIC CALCULATIONS
7. SCM DESIGN CALCULATIONS
180 Perry Drive • Southern Pines, NC 28387 • P: [phone] • License# P-2463
www . sandersengineers . com

GENERAL DESCRIPTION
Located on the West side of S. Main Street and approximately 0.50-mile South of US Highway 74
in the Town of Wingate in Union County, North Carolina, is the proposed development known as
Stewarts Grove. The existing site consists of open grassed areas and wooded areas. Proposed
development on this site will consist of the construction of single- family homes, along with
associated roads, sidewalks, utility improvements and one stormwater control measure.
The proposed development is located within the Yadkin River basin with stormwater runoff from
the proposed development draining into Rays Fork (13-17-36-8) in the Richardson Creek
Watershed. Per Town of Wingate regulations, stormwater management on this site shall meet
the stormwater management performance standards for development set forth in the Town of
Wingate Code of Land Ordinances & NCDEQ MDC.
To meet the above requirements, one Stormwater Wetland (SCM) is being proposed to control
post-development peak runoff rates to their pre-development condition. Please refer to the
appropriate section of this report for additional information.
CALCULATION METHODOLOGY
➢ Rainfall data for the analysis was taken from NOAA' s database for the Town of Wingate.
Please reference the precipitation information within this report for additional
information.
➢ Using USDA Web Soil Survey for Union County, the on-site soils were determined to be
hydrologic soil group (HSG) ' C' soils.
➢ A composite SCS Curve Number was calculated for both the pre- and post -development
condition for each sub -basin using SCS curve numbers and land cover conditions. Land
cover conditions for the pre -development condition were taken from available survey
and GIS information. Land cover conditions for the post -development condition were
taken from the proposed development plan.
➢ Hydrocad V10.20-2f was used in determining the pre- & post -development peak flow
rates for the 1-, 10-, and 100- year storm events, as well as routing calculations for the
proposed stormwater control measures.
➢ The proposed stormwater control measures were designed in accordance with the
Minimum Design Criteria (MDC standards set forth in the NCDEQ Stormwater Design
Manual.
180 Perry Drive • Southern Pines, NC 28387 • P: [phone] • License# P-2463
www . sandersengineers . com

SUMMARY OF RESULTS
180 Perry Drive • Southern Pines, NC 28387 • P: [phone] • License# P-2463
www . sandersengineers . com

Release Rate Results
Point of Interest#1 (1L)
Pre-Dev Post-Dev
Return Period % Increase
(cfs) (cfs)
1-year 2.38 7.73 224.79%
10-year 7.6 46.89 516.97%
100-year 14.82 100.19 576.05%
Point of Interest#2 (2L)
Pre-Dev Post-Dev
Return Period % Increase
(cfs) (cfs)
1-year 1.41 1.5 6.38%
10-year 4.33 3.82 -11.78%
100-year 8.3 6.78 -18.31%
Point of Interest#3 (3L)
Pre-Dev Post-Dev
Return Period % Increase
(cfs) (cfs)
1-year 31.3 16.62 -46.90%
10-year 78.76 41.05 -47.88%
100-year 139.64 71.85 -48.55%
Point of Interest#4 (4L)
Pre-Dev Post-Dev
Return Period % Increase
(cfs) (cfs)
1-year 12.38 11.05 -10.74%
10-year 33.3 30.85 -7.36%
100-year 60.56 56.94 -5.98%
Overall Site (5L) *
Pre-Dev Post-Dev
Return Period % Increase
(cfs) (cfs)
1-year 46.06 29.4 -36.17%
10-year 120.9 93.51 -22.66%
100-year 217.72 184.65 -15.19%
-
*Overall site has a Post Development net reduction in peak runoff
for all storm events
180 Perry Drive • Southern Pines, NC 28387 • P: [phone] • License# P-2463
www . sandersengineers . com

MISCELLANEOUS SITE INFORMATION
180 Perry Drive • Southern Pines, NC 28387 • P: [phone] • License# P-2463
www . sandersengineers . com

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National Transportation Dataset;USGS Globa"fTEcosystems;U.S.Census Bureau
'TIGER/Line data;USFS Road Data;Natural Earth Data;U.S.Department of State
Humanitarian Information Unit;and NOAA National Centers for Environmental
Information, U.S.Coastal Relief Model.Data refreshed June,2022.
SANDERS 180 Perry Road
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160 NC
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3/10/23 1"=600 Feet

3 Soil Map—Union County, North Carolina 3
NF (Stewarts Grove Subdivision)
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N Map Scale:1:2,740 if printed on A portrait(8.5"x 11")sheet -
Meters
m N 0 40 80 160 2 $
Feet
0 100 Z00 400 600
Map projection:Web Mercator Comer coordinates:WGS84 Edge tics:UTM Zone 17N WGS84
USDA Natural Resources Web Soil Survey 3/10/2023
1011. Conservation Service National Cooperative Soil Survey Page 1 of 3

Soil Map—Union County,North Carolina
(Stewarts Grove Subdivision)
MAP LEGEND MAP INFORMATION
Area of Interest(AOI) Spoil Area The soil surveys that comprise your AOI were mapped at
Area of Interest(AOI) 1:24,000.
Q Stony Spot
Soils Very Stony Spot Warning:Soil Map may not be valid at this scale.
0 Soil Map Unit Polygons
Wet Spot Enlargement of maps beyond the scale of mapping can cause
.�� Soil Map Unit Lines misunderstanding of the detail of mapping and accuracy of soil
Other line placement.The maps do not show the small areas of
p Soil Map Unit Points contrasting soils that could have been shown at a more detailed
Special Line Features
Special Point Features scale.
(9 Blowout Water Features
Streams and Canals Please rely on the bar scale on each map sheet for map
cs Borrow Pit measurements.
Transportation
X Clay Spot Rails Source of Map: Natural Resources Conservation Service
0 Closed Depression Web Soil Survey URL:
ti Interstate Highways Coordinate System: Web Mercator(EPSG:3857)
X Gravel Pit US Routes
Maps from the Web Soil Survey are based on the Web Mercator
,. Gravelly Spot Major Roads projection,which preserves direction and shape but distorts
distance and area.A projection that preserves area,such as the
0 Landfill Local Roads Albers equal-area conic projection,should be used if more
Lava Flow accurate calculations of distance or area are required.
Background
46 Marsh or swamp Aerial Photography This product is generated from the USDA-NRCS certified data as
of the version date(s)listed below.
iRk Mine or Quarry
Soil Survey Area: Union County, North Carolina
O Miscellaneous Water Survey Area Data: Version 23,Sep 12,2022
Q Perennial Water Soil map units are labeled(as space allows)for map scales
v Rock Outcrop 1:50,000 or larger.
▪ Saline Spot Date(s)aerial images were photographed: Apr 17,2022—May
20,2022
Sandy Spot
The orthophoto or other base map on which the soil lines were
Severely Eroded Spot compiled and digitized probably differs from the background
imagery displayed on these maps.As a result,some minor
• Sinkhole shifting of map unit boundaries may be evident.
3) Slide or Slip
oa Sodic Spot
Natural Resources Web Soil Survey 3/10/2023
001. Conservation Service National Cooperative Soil Survey Page 2 of 3

Soil Map—Union County, North Carolina Stewarts Grove Subdivision
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
BdB2 Badin channery silty clay loam, 8.8 56.5%
2 to 8 percent slopes,
moderately eroded
BdC2 Badin channery silty clay loam, 6.7 43.5%
8 to 15 percent slopes,
moderately eroded
Totals for Area of Interest 15.5 100.0%
USDA Natural Resources Web Soil Survey 3/10/2023
Conservation Service National Cooperative Soil Survey Page 3 of 3

Map Unit Description(Brief,Generated)---Union County, North Carolina Stewarts Grove Subdivision
Map Unit Description (Brief, Generated)
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 in this
report, along with the maps, provide information on the composition of map units
and properties of their components.
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.
The Map Unit Description (Brief, Generated) report displays a generated
description of the major soils that occur in a map unit. Descriptions of non-soil
(miscellaneous areas)and minor map unit components are not included. This
description is generated from the underlying soil attribute data.
Additional information about the map units described in this report is available in
other Soil Data Mart reports, which give properties of the soils and the limitations,
capabilities, and potentials for many uses. Also, the narratives that accompany
the Soil Data Mart reports define some of the properties included in the map unit
descriptions.
Report—Map Unit Description (Brief, Generated)
Union County, North Carolina
Map Unit: BdB2—Badin channery silty clay loam, 2 to 8 percent slopes,
moderately eroded
Component: Badin, moderately eroded (85%)
The Badin, moderately eroded component makes up 85 percent of the map unit.
Slopes are 2 to 8 percent. This component is on interfluves, uplands. The parent
material consists of residuum weathered from metavolcanics and/or argillite.
Depth to a root restrictive layer, bedrock, paralithic, is 20 to 40 inches. The
natural drainage class is well drained. Water movement in the most restrictive
layer is very low. Available water to a depth of 60 inches (or restricted depth) is
low. Shrink-swell potential is moderate. This soil is not flooded. It is not ponded.
There is no zone of water saturation within a depth of 72 inches. Organic matter
content in the surface horizon is about 1 percent. This component is in the
F136XY830NC Acidic upland forest, dry-moist ecological site. Nonirrigated land
capability classification is 2e. This soil does not meet hydric criteria.
USDA Natural Resources Web Soil Survey 3/10/2023
Conservation Service National Cooperative Soil Survey Page 1 of 2

Map Unit Description(Brief,Generated)---Union County, North Carolina Stewarts Grove Subdivision
Map Unit: BdC2—Badin channery silty clay loam, 8 to 15 percent slopes,
moderately eroded
Component: Badin, moderately eroded (85%)
The Badin, moderately eroded component makes up 85 percent of the map unit.
Slopes are 8 to 15 percent. This component is on hillslopes on ridges, uplands.
The parent material consists of residuum weathered from metavolcanics and/or
argillite. Depth to a root restrictive layer, bedrock, paralithic, is 20 to 40 inches.
The natural drainage class is well drained. Water movement in the most
restrictive layer is very low. Available water to a depth of 60 inches (or restricted
depth) is low. Shrink-swell potential is moderate. This soil is not flooded. It is not
ponded. There is no zone of water saturation within a depth of 72 inches.
Organic matter content in the surface horizon is about 1 percent. This component
is in the F136XY830NC Acidic upland forest, dry-moist ecological site.
Nonirrigated land capability classification is 3e. This soil does not meet hydric
criteria.
Data Source Information
Soil Survey Area: Union County, North Carolina
Survey Area Data: Version 23, Sep 12, 2022
USDA Natural Resources Web Soil Survey 3/10/2023
Conservation Service National Cooperative Soil Survey Page 2 of 2

Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=34.9825&lon.-80.4508&data=d...
NOAA Atlas 14,Volume 2,Version 3
S. Location name:Wingate,North Carolina,USA* ,. jFiN
I Latitude:34.9825°,Longitude:-80.4508°
`�
�y, �'• Elevation:m/ft**
"*source:ESRI Mapsv,,�,y �'
**source:USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M.Bonnin,D.Martin,B.Lin,T.Parzybok,M.Yekta,and D.Riley
NOAA,National Weather Service,Silver Spring,Maryland
PF_tabular I PF_graphical I Maps_&_aerials
PF tabular
PDS-based point precipitation frequency estimates with 90%confidence intervals(in inches)1
Average recurrence interval(years)
Duration i
1 2 5 10 25 50 100 200 500 1000
5-min 0.430 0.508 0.589 0.648 0.716 0.762 0.805 0.843 0.887 0.918
(0.396-0.467)(0.467-0.554)(0.540-0.642)(0.594-0.704)(0.653-0.776)(0.692-0.826)(0.727-0.872)(0.758-0.915)(0.790-0.964)(0.811-1.00)
10-min 0.687 0.813 0.944 1.04 1.14 1.21 1.28 1.34 1.40 1.45
(0.632-0.746)(0.746-0.885) (0.865-1.03) (0.949-1.13) (1.04-1.24) (1.10-1.32) (1.16-1.39) (1.20-1.45) (1.25-1.53) (1.28-1.58)
15-min 0.858 1.02 1.19 1.31 1.45 1.54 1.62 1.69 1.77 1.82
(0.790-0.932) (0.938-1.11) (1.10-1.30) (1.20-1.42) (1.32-1.57) (1.40-1.67) (1.46-1.75) (1.52-1.83) (1.57-1.92) (1.60-1.98)
30-min 1.18 1.41 1.70 1.90 2.14 2.32 2.48 2.63 2.81 2.94
(1.08-1.28) (1.30-1.54) (1.56-1.85) (1.74-2.06) (1.95-2.32) (2.10-2.51) (2.24-2.68) (2.36-2.85) (2.50-3.06) (2.60-3.20)
60-min 1.47 1.77 2.17 2.48 2.85 3.14 3.41 3.68 4.03 4.29
(1.35-1.59) (1.63-1.93) (1.99-2.37) (2.27-2.69) (2.60-3.09) (2.85-3.40) (3.08-3.70) (3.31-4.00) (3.59-4.38) (3.79-4.68)
2-hr 1.69 2.05 2.54 2.91 3.39 3.76 4.12 4.48 4.96 5.33
(1.55-1.85) (1.88-2.24) (2.32-2.78) (2.66-3.18) (3.08-3.69) (3.40-4.09) (3.71-4.49) (4.00-4.88) (4.38-5.40) (4.66-5.81)
3-hr 1.80 2.17 2.71 3.13 3.69 4.13 4.58 5.04 5.67 6.17
(1.64-1.98) (1.99-2.39) (2.48-2.98) (2.85-3.43) (3.34-4.04) (3.72-4.51) (4.09-4.99) (4.46-5.49) (4.96-6.19) (5.34-6.74)
6-hr 2.15 2.60 3.24 3.75 4.44 4.99 5.55 6.13 6.93 7.57
(1.97-2.36) (2.38-2.85) (2.96-3.56) (3.42-4.11) (4.02-4.85) (4.48-5.43) (4.95-6.04) (5.42-6.67) (6.05-7.54) (6.52-8.23)
12-hr 2.54 3.07 3.85 4.48 5.34 6.04 6.76 7.52 8.59 9.45
(2.33-2.79) (2.82-3.38) (3.52-4.23) (4.08-4.91) (4.83-5.84) (5.42-6.59) (6.01-7.37) (6.61-8.19) (7.43-9.34) (8.06-10.3)
24-hr 3.02 3.64 4.58 5.32 6.37 7.21 8.09 9.02 10.3 11.4
(2.78-3.27) (3.36-3.95) (4.22-4.96) (4.89-5.77) (5.82-6.90) (6.57-7.82) (7.34-8.78) (8.15-9.80) (9.26-11.2) (10.2-12.4)
2-day 3.55 4.27 5.34 6.18 7.36 8.32 9.32 10.4 11.8 13.0
(3.28-3.85) (3.95-4.64) (4.93-5.79) (5.70-6.70) (6.76-7.98) (7.61-9.02) (8.48-10.1) (9.38-11.3) (10.6-12.9) (11.6-14.3)
3-day 3.76 4.52 5.62 6.49 7.70 8.69 9.71 10.8 12.3 13.5
(3.49-4.06) (4.19-4.89) (5.20-6.07) (5.99-7.01) (7.09-8.33) (7.96-9.40) (8.87-10.5) (9.80-11.7) (11.1-13.4) (12.1-14.7)
4-day 3.98 4.77 5.89 6.79 8.04 9.05 10.1 11.2 12.8 14.0
(3.69-4.28) (4.43-5.14) (5.46-6.36) (6.28-7.32) (7.41-8.67) (8.32-9.77) (9.25-10.9) (10.2-12.1) (11.6-13.8) (12.7-15.2)
7-day 4.59 5.47 6.68 7.64 8.97 10.0 11.2 12.3 14.0 15.3
(4.29-4.91) (5.13-5.87) (6.24-7.15) (7.13-8.18) (8.34-9.62) (9.31-10.8) (10.3-12.0) (11.3-13.2) (12.8-15.0) (13.9-16.5)
10-day 5.27 6.28 7.56 8.57 9.94 11.0 12.1 13.3 14.8 16.1
(4.96-5.62) (5.89-6.68) (7.08-8.05) (8.02-9.13) (9.28-10.6) (10.3-11.8) (11.3-12.9) (12.3-14.2) (13.7-15.9) (14.8-17.3)
20-day 7.08 8.36 9.88 11.1 12.7 14.0 15.3 16.6 18.4 19.9
(6.68-7.51) (7.89-8.86) (9.31-10.5) (10.4-11.8) (11.9-13.5) (13.1-14.9) (14.3-16.3) (15.5-17.7) (17.1-19.7) (18.4-21.2)
30-day 8.69 10.2 11.9 13.2 14.9 16.3 17.6 18.9 20.6 22.0
(8.23-9.17) (9.69-10.8) (11.3-12.6) (12.5-13.9) (14.1-15.7) (15.3-17.2) (16.5-18.6) (17.7-20.0)I (19.3-21.9) (20.5-23.4)
45-day 10.9 12.8 14.7 16.1 18.0 19.4 20.8 22.2 24.0 25.3
(10.4-11.5) (12.2-13.5) (14.0-15.4) (15.3-16.9) (17.1-18.9) (18.4-20.4) (19.7-21.9) (20.9-23.3) (22.5-25.3) (23.7-26.8)
60-day 13.1 15.3 17.3 18.9 20.9 22.4 23.9 25.3 27.1 28.5
(12.5-13.7) (14.6-16.0) (16.5-18.1) (18.0-19.7) (19.9-21.8) (21.3-23.4) (22.6-25.0) (24.0-26.5) (25.6-28.5) (26.9-30.0)
1 Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval.The probability that precipitation frequency estimates
(for a given duration and average recurrence interval)will be greater than the upper bound(or less than the lower bound)is 5%.Estimates at upper bounds
are not checked against probable maximum precipitation(PMP)estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
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PF graphical
1 of 3 3/10/2023,4:17 PM

Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=34.9825&lon—80.4508&data=d...
PDS-based depth-duration-frequency(DDF)curves
Latitude: 34.9825°,Longitude:-80.4508°
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— 60-min- 2-hr— 3-hr— 6a1r— 12-hr— 24-hr
1 2 5 10 25 50 100 200 500 1000
Average recurrence interval(years)
NOAA Atlas 14,Volume 2,Version 3 Created(GMT):Fri Mar 10 21:14:31 2023
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Maps & aerials
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2 of 3 3/10/2023,4:17 PM

Precipitation Frequency Data Server https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=34.9825&lon=80.4508&data=d...
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3 of 3 3/10/2023,4:17 PM

PRE-DEVELOPMENT HYDROLOGIC CALCULATIONS
180 Perry Drive • Southern Pines, NC 28387 • P: [phone] • License# P-2463
www . sandersengineers . com

PRE-DEVELOPMENT
DRAINAGE AREAS
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PRE DEVELOPMENT
0 I>
1L
1 POI#1-PRE
D 2L
2 POI#2-PRE
0-------____
4�
3 3L I> 5L
(3A) 11
POI#3-PRE 'RE-DEV. TOTAL
I
3A-OFFSITE
4
4
/4A\ -> 4L
I 4-OFFSITE P0I#4-PRE
(4B)
4-OFFSITE
(Subca) Reach 'on. MI Routing Diagram for SCM-PRE
Prepared by Sanders Engineering, PLLC, Printed 6/21/2023
HydroCAD®10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC

STEWARTS GROVE SUBDIVISION
SCM-PRE
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 2
Rainfall Events Listing (selected events)
Event# Event Storm Type Curve Mode Duration B/B Depth AMC
Name (hours) (inches)
1 lyr Type II 24-hr Default 24.00 1 3.02 2
2 10yr Type II 24-hr Default 24.00 1 5.32 2
3 100yr Type II 24-hr Default 24.00 1 8.09 2

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 3
Summary for Subcatchment 1: 1
Runoff = 2.38 cfs @ 12.27 hrs, Volume= 10,845 cf, Depth> 0.86"
Routed to Link 1L : POI#1-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
151,202 73 Woods, Fair, HSG C
151,202 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.1 100 0.0200 0.08 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.64"
6.7 300 0.0220 0.74 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
2.8 300 0.1300 1.80 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
29.6 700 Total
Subcatchment 1: 1
Hydrograph
llllllllllllllllllll ❑Runoff
2.38 cfs©12.27 hrs
Runoff=2.38 cfs;@ 12.27 hrs
-- 1111117.17ype..11.-.2--. -hr--..-.
i i 11 1 1 I i i
1yr Rainfall=3.02"
•
;Runoff Area=151,202 Sf
y _ 1 1 I 1 1 1 I 1 1 0 Runoff Volume=1 Q,845 Of
3 RunoffDepth>0.86"
LL i i i gth=709'..._...
Tc:29 6min
CN=73
.... .. ..
o
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 4
Summary for Subcatchment 2: 2
Runoff = 1.41 cfs @ 12.21 hrs, Volume= 5,707 cf, Depth> 0.91"
Routed to Link 2L : POI#2-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
74,996 74 >75% Grass cover, Good, HSG C
74,996 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
21.2 100 0.0175 0.08 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.64"
4.1 300 0.0600 1.22 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
25.3 400 Total
Subcatchment 2: 2
Hydrograph
❑Runoff
liaicfs@l221hrsI
Runoff=1 41 cfs'@ 12.21 hrs
Type II 24-hr
lyr Rainfall=3.02"
1- / 74996
Runoff V:.ume=5,707 cf
- RunoffDepth>0.91"
LL 0 Flow Length=400'
/ Tc=25.3'min
CN=14
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 5
Summary for Subcatchment 3: 3
Runoff = 7.27 cfs @ 12.13 hrs, Volume= 24,396 cf, Depth> 0.92"
Routed to Link 3L : POI#3-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
319,833 74 >75% Grass cover, Good, HSG C
319,833 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
7.8 100 0.0300 0.21 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
10.9 400 0.0150 0.61 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
18.7 500 Total
Subcatchment 3: 3
Hydrograph
8llllll lllll •Runoff
1:7.27 cfs @ 12.13 hrs I
7_ Runoff=7 27 cfs @:1 213 hrs
Type II 24-hr
6_,. ll 'lyr Rainfall=3.02lllllllllllll
5-- i
Runoff V ume=24 396 Of
4=- 1111 Runoff:Depth>0.92"
o
LL 1 h5
....:..... ....:....
3_ 00'
Tc=18.7 min
lllllll
2-
.. .. .. .. . . . . . kiall 1 . .
1-
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 6
Summary for Subcatchment 3A: 3A-OFFSITE
Runoff = 24.06 cfs @ 12.14 hrs, Volume= 80,999 cf, Depth> 1.45"
Routed to Link 3L : POI#3-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
145,089 98 Paved parking, HSG C
523,133 79 50-75% Grass cover, Fair, HSG C
668,222 83 Weighted Average
523,133 78.29% Pervious Area
145,089 21.71% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
7.7 400 0.0300 0.87 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
4.1 300 0.0600 1.22 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
21.0 800 Total
Subcatchment 3A: 3A-OFFSITE
Hydrograph iiiiii
26 ❑Runoff
_ ...... o
�24.6 cfs @ 12.14
4 hrs I__ _.-- ...... ___
24! " Runoff-24 06 cfs @ 1 .14 hits
22 1 1 1 1 1 1 1 1 1 1 '........ ._........ .......... `........ . Type II 24-hr
20 1 1 i / 11Yr Rainfall=3.02"
18 1 1 1 1 i 1 1 1 1 1 1 Runoff'Area=668,222 sf
16= / Runoff Volume=80,999 Of
14 1 1 1 1 1 1 1 1 1 1 Runoff Depth>1.45"
Flow Len th=800'
LL 12 g
10
- c �
iiiiiiiiii
CS1=63
6-
_ 1, 1 1 1, ! ! f f f
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 7
Summary for Subcatchment 4: 4
Runoff = 8.78 cfs @ 12.07 hrs, Volume= 24,625 cf, Depth> 1.20"
Routed to Link 4L : POI#4-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
246,614 79 50-75% Grass cover, Fair, HSG C
246,614 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
5.3 300 0.0350 0.94 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
14.5 400 Total
Subcatchment 4: 4
/ Hydrograph
- ❑Runoff
9 L878cfs@1zmhrs I... .....
illiiiiiiill Runoff 8 78 cfs @ 12.07 hrs
$_ Type II 24-Ir
7 / 'lyr Rainfall=3.02
-ulnot#-Area-
246,61.4... f.
6-
Niiiii Runoff-;Volume=24z625 cf.-..-..
3 5-' Depth>11.20"
Runoff
LL 4= ' 1 I I / :Flow Length400
,-- -- -..
- - - - -=Tc; 14.5;min_..
3-
CN=79
2-
I/
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type 1124-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 8
Summary for Subcatchment 4A: 4-OFFSITE
Runoff = 3.92 cfs @ 12.18 hrs, Volume= 14,599 cf, Depth> 1.02"
Routed to Link 4L : POI#4-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
14,354 98 Paved parking, HSG C
157,226 74 >75% Grass cover, Good, HSG C
171,580 76 Weighted Average
157,226 91.63% Pervious Area
14,354 8.37% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) _ (feet) (ft/ft) (ft/sec) (cfs)
15.0 100 0.0150 0.11 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.64"
8.1 500 0.0425 1.03 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
23.1 600 Total
Subcatchment 4A: 4-OFFSITE
Hydrograph
0 Runoff
I39 8 hrsR' _.._.. ff 3 92 f@ 1 1 h
2cfs@ 12.1 i
`� uno c s 2'. 8 irs
Type II 24-hr
:.................................................................................................._..... / 1yr Rainfall=3.02"-__
3f. Runoff Area=171,580 sf
y - Runoff Volume=14,599 cf
;.- Depth>1.02"-- � Runoff 1.
2-
LL Flow Length=600'
0- 1 Tc=23.1 min
1
- i i
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 9
Summary for Subcatchment 4B: 4-OFFSITE
Runoff = 0.52 cfs @ 12.02 hrs, Volume= 1,237 cf, Depth> 0.97"
Routed to Link 4L : POI#4-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
512 98 Paved parking, HSG C
14,769 74 >75% Grass cover, Good, HSG C
15,281 75 Weighted Average
14,769 96.65% Pervious Area
512 3.35% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
Subcatchment 4B: 4-OFFSITE
Hydrograph
Runoff
0.55-' ` Lo.52 cfs @ f 2.02 hrs I
_
0.5_'
i
_ .... -... ._ ..... .._...... ..... ..... + .....i ......+ 11 yt. ROAriffall=1.02"
0.4-' i ,
.... _..... R4nOff;Aria. 1�,28.1.....�.f.-..-..
0.35-: i 1 1 1 1 1 1 Runoff Volume=1 237 cf
0.3-' Runoff D epth>0.97',
LL 0.25 1' 111Flow Length=100'
0.2- Mope=0.0200_..'I'_.
0.15-' _
Tc 2 m in
.1-'� i .... ......._ CN 75
i !
0.05-" '
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 10
Summary for Subcatchment 1: 1
Runoff = 7.60 cfs @ 12.25 hrs, Volume= 31,671 cf, Depth> 2.51"
Routed to Link 1L : POI#1-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
151,202 73 Woods, Fair, HSG C
151,202 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.1 100 0.0200 0.08 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.64"
6.7 300 0.0220 0.74 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
2.8 300 0.1300 1.80 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
29.6 700 Total
Subcatchment 1: 1
Hydrograph
Runoff
8: t t 17.60 cfs 1225 hrsl
I� ._. Run Off-76 Q_Of s @12 25 hrs
Type II 24-hr
10yr R =
ainfall 5.
.........................................._........................................................_..... ,...... Runoff Area='I 5'I,2p2 sf
5- / Runoff Volume=31,671 cf
111111111 3 ° Runoff°Depth>2.5
LL 4 700'
3- 1 I Tc`29
_ 6;mien
2- i i II 1 1 1 i i 0
M
.....:....
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 11
Summary for Subcatchment 2: 2
Runoff = 4.33 cfs @ 12.19 hrs, Volume= 16,277 cf, Depth> 2.60"
Routed to Link 2L : POI#2-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
74,996 74 >75% Grass cover, Good, HSG C
74,996 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
21.2 100 0.0175 0.08 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.64"
4.1 300 0.0600 1.22 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
25.3 400 Total
Subcatchment 2: 2
Hydrograph
- ■Runoff
4.33 cfs @ 12.19 hrs Ii i Ili
------.-------- ---- - c�..f -4.� 3._.Gfs..Q. 12._1-0....hrs........
....;....Run-
4 Type 1124-h r
10yr Rainfall=5.32"
......... ....... rea=7.4...996f.......
AV Rtrntfff A
3
N - • Runoff Volume=16,277 cf
Iiiiepth
LL ................:..........._e..............,..............,..........................._..... _. u n off D 2 60
2 Flow Length=400'
/ Tc=25.3 min
- „ , ! ! „ „ : 0 1 1CN=74
1-'
i
i .. . . . . . .
AL
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 12
Summary for Subcatchment 3: 3
Runoff = 22.08 cfs @ 12.12 hrs, Volume= 69,548 cf, Depth> 2.61"
Routed to Link 3L : POI#3-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
319,833 74 >75% Grass cover, Good, HSG C
319,833 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
7.8 100 0.0300 0.21 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
10.9 400 0.0150 0.61 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
18.7 500 Total
Subcatchment 3: 3
Hydrograph
................ ..........
Runoff
22.O8 cfs @ 12.12 hrs.
22= Offt-22'.08 cfs....aj._�
20=' :. I .... Type II4-ht'
19 - ` ........._............._.........................._......_....._................................
18--' ............. ........+ ........ .......... -......... .. .. ........._.... ....; _;.... .._...... ........ ..._;.... ...;.10.yr.Rainfall ..5.. .
16_- Runo A -rea=3 9,833 sf......
15'. ............. ..... =60,548....cf.....
Ut1OfF tfofum
u 13= + Runoff Depth>2.61".......
11= ngth=5;_ _, Flow Le _.. 0
!.......... ..... ..... ....
8= If i
1
i
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 13
Summary for Subcatchment 3A: 3A-OFFSITE
Runoff = 56.93 cfs @ 12.14 hrs, Volume= 192,052 cf, Depth> 3.45"
Routed to Link 3L : POI#3-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
145,089 98 Paved parking, HSG C
523,133 79 50-75% Grass cover, Fair, HSG C
668,222 83 Weighted Average
523,133 78.29% Pervious Area
145,089 21.71% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
7.7 400 0.0300 0.87 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
4.1 300 0.0600 1.22 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
21.0 800 Total
Subcatchment 3A: 3A-OFFSITE
Hydrograph
.........................-° ....... ......+ -......... .. ❑Runoff
607 12.14 hrs'.. uno
I �5693 cfs@
........... ...... .... . ..... ©ff= ._
56 93 cf .._.
R ._..1..2..14_hrs_._..
55=
Type
50= T....
fa - 32
45_ �•
=668,222 sf
yr ain
_ - 1�un+affArea
40_'
- 92,052 Of
. -......- __. ....._R�.n.off.Val_urne.-1
1 35 Ru roof# De 5"
........................................_..........................._i............_..................... .__! pth>�.4
6307 Flow Length=800'
25= Tc=21.0 min
..........
20 CN=$3...
15' ! # . 1 i 1 1 1 1 1 1 i
.
i
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 14
Summary for Subcatchment 4: 4
Runoff = 22.73 cfs @ 12.06 hrs, Volume= 63,068 cf, Depth> 3.07"
Routed to Link 4L : POI#4-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
246,614 79 50-75% Grass cover, Fair, HSG C
246,614 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
5.3 300 0.0350 0.94 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
14.5 400 Total
Subcatchment 4: 4
Hydrograph
25-
•Runoff
cfs @ 12.06 hrs
I
22_
.i..........._............_t............_i............. o............_c............................:. ...... __..... .. . . .... .. .. . . . . ........
4Oyr
. ........................_............................................_........................._.............. Rainfall _ ,
17 ; I Run-off a4rea=246,614 sf
1.. e�^ 15 I.... , �sY uno-ff.-Valum�....6 68...cf
Fri lit 1 D 1, n
i.... .F .u.nof#..
Fto
e:n:+9:#h
10= / ... Tc=14.5m n.......
8 - .CN 79.....
7
0.
5
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 15
Summary for Subcatchment 4A: 4-OFFSITE
Runoff = 11.23 cfs @ 12.16 hrs, Volume= 39,822 cf, Depth> 2.79"
Routed to Link 4L : POI#4-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
14,354 98 Paved parking, HSG C
157,226 74 >75% Grass cover, Good, HSG C
171,580 76 Weighted Average
157,226 91.63% Pervious Area
14,354 8.37% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 100 0.0150 0.11 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.64"
8.1 500 0.0425 1.03 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
23.1 600 Total
Subcatchment 4A: 4-OFFSITE
Hydrograph iiiiiiiii
12= ■Runoff
_ ..........._._..........._.............................. ........................._.............._ __ .11 23 cfs @ 12.16 hrs I
1171 1 1 1 1 1 1 1 1 1 1 Runoff=1123cfs@12.16hrs
10 Type it 24-hr
9_ � 11Oyr fainfa II5
rea=171,580.Of ..
_ Runoff Volume=39,822 cf
w 7-
Runoff De
6-' h=6 6'
5 Tc=2:3.1 min
4I 1CN=76
3_ I /
2_
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 16
Summary for Subcatchment 4B: 4-OFFSITE
Runoff = 1.49 cfs @ 12.01 hrs, Volume= 3,445 cf, Depth> 2.71"
Routed to Link 4L : POI#4-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
512 98 Paved parking, HSG C
14,769 74 >75% Grass cover, Good, HSG C
15,281 75 Weighted Average
14,769 96.65% Pervious Area
512 3.35% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
Subcatchment 4B: 4-OFFSITE
Hydrograph
•Runoff
L1.49 cfs @ 12.01 hrs I
Runoff=1.49 cfs:@ 12.01 hrs
11111111Iv Type II 24-hr
1Oy1' Rainfall=5.32"
......... ..... ..... rea*1 5 281 Sf........
Ru Hoff--A
w
1 Runoff Volume=3,445 cf
3 Runoff:Depth>2.71"
LL Flow ;Length=100'
Slope=0.0200 'I'
_ Tc=9.2 m in
CN=75
IIIIIIIII
,r
0 / // ///% /%/
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 17
Summary for Subcatchment 1: 1
Runoff = 14.82 cfs @ 12.24 hrs, Volume= 61,176 cf, Depth> 4.86"
Routed to Link 1L : POI#1-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
151,202 73 Woods, Fair, HSG C
151,202 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.1 100 0.0200 0.08 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.64"
6.7 300 0.0220 0.74 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
2.8 300 0.1300 1.80 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
29.6 700 Total
Subcatchment 1: 1
Hydrograph
iiiiiii
16I i i iiiiiiiiiiiii ■Runoff
114.82 cfs @ 1224 hrs i.......J
14 '
12 Oyr —
1
.... ...... ...... ..... .... ...... ..... .... .... ..... .... ... _AreaRainfall__
11= ' .... ..... Runoff =151,202...sf....
p
10 ............_..........._ ........... ..........__ 1[ . 1.11.oft'...VSa.Iu mr�e.=.G_1..y.1.7.G_..C.f.._..
•
9 6".......
_.... ..--Ru-r�af#.-.D-�pth�4.8
'
i
1
8= Fipvi Length 70- ........
: / 11111iiill Or
5=
/4
3
I
2 I z
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 18
Summary for Subcatchment 2: 2
Runoff = 8.30 cfs @ 12.19 hrs, Volume= 31,103 cf, Depth> 4.98"
Routed to Link 2L : POI#2-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
74,996 74 >75% Grass cover, Good, HSG C
74,996 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
21.2 100 0.0175 0.08 Sheet Flow,
Woods: Light underbrush n= 0.400 P2= 3.64"
4.1 300 0.0600 1.22 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
25.3 400 Total
Subcatchment 2: 2
Hydrograph
......... .
9:' ■Runoff
1 8.30 cfs @ 12.19 hrs I
111111111 8-'
uno c s rs
..-..-.._. ..-.. i-..
7=_ y
pe�12
0hr
....
1 d0yr Rorifall_ . 9"
6_ ' I RunoffArea-74,986 of
5 .........................._............._ ...... Runoff Volume=31,103 of
o 1111 Runoff Depth>4.98"
0
LL 4 Flow 1Length400'
3-
•
o _/%i/////i///////%i%iiii •
/
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 19
Summary for Subcatchment 3: 3
Runoff = 42.13 cfs @ 12.11 hrs, Volume= 132,865 cf, Depth> 4.99"
Routed to Link 3L : POI#3-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
319,833 74 >75% Grass cover, Good, HSG C
319,833 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
7.8 100 0.0300 0.21 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
10.9 400 0.0150 0.61 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
18.7 500 Total
Subcatchment 3: 3
Hydrograph
i----- + .46 " •Runoff
..-......_..i..........._............_i............_........... 42.13 cfs @ 12.11
........................
hrs .
42 ' _ 1211hrs.::
40= I ,.
384 I..-. _ i T. '-pe--1124-hr
r.Faiafai=8;09__ .....
11 1. 1!............_............_........................ . HI kun"off=Area 319 833 sf
l un me 1.34805 c#_..
28= o#f Vo�u
24_ ;......-.. ; � - -1iii - D.iepfh5:4:�99-..
0 22 ;...... // h 5 4:1---...
i
12
1°8 °°
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 20
Summary for Subcatchment 3A: 3A-OFFSITE
Runoff = 97.77 cfs @ 12.13 hrs, Volume= 336,210 cf, Depth> 6.04"
Routed to Link 3L : POI#3-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
145,089 98 Paved parking, HSG C
523,133 79 50-75% Grass cover, Fair, HSG C
668,222 83 Weighted Average
523,133 78.29% Pervious Area
145,089 21.71% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
7.7 400 0.0300 0.87 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
4.1 300 0.0600 1.22 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
21.0 800 Total
Subcatchment 3A: 3A-OFFSITE
Hydrograph
105=
I i I
❑Runoff
7 13 hrs..i...
_.........._............_............--._._-.. � ifs @ 12. .._.._..._........__j._..........
954 :....... :........ i -..-. i...-. ......-.. i ..-..I RO_n.qff-97.$77;_cf*....g.._1.2.._1._4.._hrs........
90_
e r.
Iflif
Yp
80= , , -... .-._.-.. .-.. I 1.90yr.Ranfah.....$.09"....
/
75 ii _..
I ,area668,2
........__ 22 sf
70= ........_.._........._............_._1.........._._
65 Runoff= -
. Run .off Volume=336,2.10 cf-07
..
60 .........................._.............._............................................_................. unoff De pth>6.04"
3 55
LL 50- ! Flow Lengthz800'..
i
35_ 11111t111 /
30 I I Ili 1- -1
.-..I
20
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 21
Summary for Subcatchment 4: 4
Runoff = 40.62 cfs @ 12.06 hrs, Volume= 114,576 cf, Depth> 5.58"
Routed to Link 4L : POI#4-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
246,614 79 50-75% Grass cover, Fair, HSG C
246,614 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
5.3 300 0.0350 0.94 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
14.5 400 Total
Subcatchment 4: 4
Hydrograph iiiiiiiiiii
■Runoff
44-42=- 1-----_---- -----+ )40.62cfs@1206ns 1---.......
3
40=:'
j ....r._......Runp#f406 cfS... ....1. .06...h .......
34= ........,.............................,..............,.............._............_i............_.............._..............:.......... _
..I 1 1 I 100Yr Ratnfall $:49"
30= . .` ......................................., ,....................................................._............_..............., .............. ,......... . Runoff Arear246,614 sf......
28= nmre*1..14,.5.76 Of._..
_ ._.-.Runoff Vo1u : ,
'G _-' ........-..
2a , , itur#off [lepth> .58 .
o : : iliiiih 4
18 ' -..
TC_
` .-.....
--..._I ..-..- ..... .----< 1 1---
10 ' I 1 '-----I---------=----I--- - - --
y
2
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 22
Summary for Subcatchment 4A: 4-OFFSITE
Runoff = 20.96 cfs @ 12.16 hrs, Volume= 74,533 cf, Depth> 5.21"
Routed to Link 4L : POI#4-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
14,354 98 Paved parking, HSG C
157,226 74 >75% Grass cover, Good, HSG C
171,580 76 Weighted Average
157,226 91.63% Pervious Area
14,354 8.37% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
15.0 100 0.0150 0.11 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.64"
8.1 500 0.0425 1.03 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
23.1 600 Total
Subcatchment 4A: 4-OFFSITE
Hydrograph
23= :........................................_....................................................._..............!.......... ■Runoff
2Z= ............_...................__ .16 hrs
o , -12096 cfs @12
21= ? Run
y� Off-20 96 cfs
0= Y
2
19 1 Ty e-11...24-hr.....
:
17 1 0yr
1,0 Ramfail $.09"
16 <.............>............_i............_............_<...... Ru rea=171,580 sf
_ noff-A
15
14= n Ruoff�lolume=7 ,553 Gf.......
RUr)off C . t .>5 ...2
12
3 114 I 4i i 4 I 0 if II F o '...
h=600 w l n
n...
8 /
r.
_ ...CN=76.....
j
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 23
Summary for Subcatchment 4B: 4-OFFSITE
Runoff = 2.77 cfs @ 12.00 hrs, Volume= 6,512 cf, Depth> 5.11"
Routed to Link 4L : POI#4-PRE
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
512 98 Paved parking, HSG C
14,769 74 >75% Grass cover, Good, HSG C
15,281 75 Weighted Average
14,769 96.65% Pervious Area
512 3.35% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
Subcatchment 4B: 4-OFFSITE
Hydrograph
3 0 Runoff
1.2.77 cfs @ 12.00 hrs I '.' I,,
1111111mr Runoff2.77 cfs:@ 12.00 hrs
11111111 ✓ 11111 Type 1124-h r
100yr Rainfall=8.09"
2— Runoff'Area_ 2.. ..1-..._._f_......
- 1 1 1 1 1 ,/ Runoff Volume=6,512 cf
Runoff:Depth>5.11"
LL Flow ;Length=100'
i i 1 „ - .
Tc=9.2'min
111111111 '/, ' 111111CN 75
/ ////////
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-PRE Type 1124-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 1
Summary for Link IL: POI#1-PRE
Inflow Area = 151,202 sf, 0.00% Impervious, Inflow Depth > 0.86" for 1yr event
Inflow = 2.38 cfs @ 12.27 hrs, Volume= 10,845 cf
Primary = 2.38 cfs @ 12.27 hrs, Volume= 10,845 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 2L: POI#2-PRE
Inflow Area = 74,996 sf, 0.00% Impervious, Inflow Depth > 0.91" for 1yr event
Inflow = 1.41 cfs @ 12.21 hrs, Volume= 5,707 cf
Primary = 1.41 cfs @ 12.21 hrs, Volume= 5,707 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 3L: POI#3-PRE
Inflow Area = 988,055 sf, 14.68% Impervious, Inflow Depth > 1.28" for 1yr event
Inflow = 31.30 cfs @ 12.14 hrs, Volume= 105,395 cf
Primary = 31.30 cfs @ 12.14 hrs, Volume= 105,395 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 4L: POI#4-PRE
Inflow Area = 433,475 sf, 3.43% Impervious, Inflow Depth > 1.12" for 1yr event
Inflow = 12.38 cfs @ 12.09 hrs, Volume= 40,461 cf
Primary = 12.38 cfs @ 12.09 hrs, Volume= 40,461 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 5L: PRE-DEV. TOTAL
Inflow Area = 1,647,728 sf, 9.71% Impervious, Inflow Depth > 1.18" for 1yr event
Inflow = 46.06 cfs @ 12.13 hrs, Volume= 162,408 cf
Primary = 46.06 cfs @ 12.13 hrs, Volume= 162,408 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs

STEWARTS GROVE SUBDIVISION
SCM-PRE Type 1124-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 2
Summary for Link IL: POI#1-PRE
Inflow Area = 151,202 sf, 0.00% Impervious, Inflow Depth > 2.51" for 10yr event
Inflow = 7.60 cfs @ 12.25 hrs, Volume= 31,671 cf
Primary = 7.60 cfs @ 12.25 hrs, Volume= 31,671 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 2L: POI#2-PRE
Inflow Area = 74,996 sf, 0.00% Impervious, Inflow Depth > 2.60" for 10yr event
Inflow = 4.33 cfs @ 12.19 hrs, Volume= 16,277 cf
Primary = 4.33 cfs @ 12.19 hrs, Volume= 16,277 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 3L: POI#3-PRE
Inflow Area = 988,055 sf, 14.68% Impervious, Inflow Depth > 3.18" for 10yr event
Inflow = 78.76 cfs @ 12.13 hrs, Volume= 261,600 cf
Primary = 78.76 cfs @ 12.13 hrs, Volume= 261,600 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 4L: POI#4-PRE
Inflow Area = 433,475 sf, 3.43% Impervious, Inflow Depth > 2.94" for 10yr event
Inflow = 33.30 cfs @ 12.08 hrs, Volume= 106,335 cf
Primary = 33.30 cfs @ 12.08 hrs, Volume= 106,335 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 5L: PRE-DEV. TOTAL
Inflow Area = 1,647,728 sf, 9.71% Impervious, Inflow Depth > 3.03" for 10yr event
Inflow = 120.90 cfs @ 12.12 hrs, Volume= 415,882 cf
Primary = 120.90 cfs @ 12.12 hrs, Volume= 415,882 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs

STEWARTS GROVE SUBDIVISION
SCM-PRE Type 1124-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 3
Summary for Link IL: POI#1-PRE
Inflow Area = 151,202 sf, 0.00% Impervious, Inflow Depth > 4.86" for 100yr event
Inflow = 14.82 cfs @ 12.24 hrs, Volume= 61,176 cf
Primary = 14.82 cfs @ 12.24 hrs, Volume= 61,176 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 2L: POI#2-PRE
Inflow Area = 74,996 sf, 0.00% Impervious, Inflow Depth > 4.98" for 100yr event
Inflow = 8.30 cfs @ 12.19 hrs, Volume= 31,103 cf
Primary = 8.30 cfs @ 12.19 hrs, Volume= 31,103 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 3L: POI#3-PRE
Inflow Area = 988,055 sf, 14.68% Impervious, Inflow Depth > 5.70" for 100yr event
Inflow = 139.64 cfs @ 12.12 hrs, Volume= 469,075 cf
Primary = 139.64 cfs @ 12.12 hrs, Volume= 469,075 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 4L: POI#4-PRE
Inflow Area = 433,475 sf, 3.43% Impervious, Inflow Depth > 5.42" for 100yr event
Inflow = 60.56 cfs @ 12.08 hrs, Volume= 195,620 cf
Primary = 60.56 cfs @ 12.08 hrs, Volume= 195,620 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : PRE-DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 5L: PRE-DEV. TOTAL
Inflow Area = 1,647,728 sf, 9.71% Impervious, Inflow Depth > 5.51" for 100yr event
Inflow = 217.72 cfs @ 12.12 hrs, Volume= 756,974 cf
Primary = 217.72 cfs @ 12.12 hrs, Volume= 756,974 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs

POST-DEVELOPMENT HYDROLOGIC CALCULATIONS
180 Perry Drive • Southern Pines, NC 28387 • P: [phone] • License# P-2463
www . sandersengineers . com

POST-DEVELOPMENT
DRAINAGE AREAS
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POST DEVELOPMENT
<OS:>
OS:2
OFFSITE DA#1 OF SITE DA#2
<DAI>
<OS:3>
DRAINGE AREA#1
Ak OFFSITE DA#3
STORM ATER
WET AND
<1B>
p 111
BYPASS-1 POI#1-POST
0 0 p
2-POST 011POI#2-POST
MI
3-BYPASS
P ST DEV. TOTAL
<3A>
3A-OFFSITE 3L
<3B>
POI#3-POST
3B-BYPASS
0 ----"\_,
4 p 4L
3C-OFFSITE BYPASS-4 P0I#4-POST
<4A>
4-OFFSITE
KSubca>
Reach 'on. MI Routing Diagram for SCM-POST
Prepared by Sanders Engineering, PLLC, Printed 6/21/2023
HydroCAD®10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC

STEWARTS GROVE SUBDIVISION
SCM-POST
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 2
Rainfall Events Listing (selected events)
Event# Event Storm Type Curve Mode Duration B/B Depth AMC
Name (hours) (inches)
1 lyr Type II 24-hr Default 24.00 1 3.02 2
2 10yr Type II 24-hr Default 24.00 1 5.32 2
3 100yr Type II 24-hr Default 24.00 1 8.09 2

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 3
Summary for Subcatchment 1 B: BYPASS-1
Runoff = 3.53 cfs @ 11.99 hrs, Volume= 7,552 cf, Depth> 0.92"
Routed to Link 1L : POI#1-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
98,576 74 >75% Grass cover, Good, HSG C
98,576 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.4 100 0.0500 0.26 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
Subcatchment 1 B: BYPASS-1
Hydrograph
D Runoff
i 3.53 cfs @ 11.99 hrs
Runoff=3.53 cfs;@11.99 hrs
3
02"
1yr Rainfall �. ;
- / RunoffArea=98,576 of
..-..-.. Runoff Volume=7,552_ cf
..-..
3 Depth> 92 ,
_
Runoff; 0.
LL Flow Length100'
- 111111111 // Slope=0.0500 'I'
-- - - - - - -- --. : ..-... - Tic_ .4--m i`n.-..-...
1-
- 1 I 1 1 1CN= 4
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 4
Summary for Subcatchment 2: 2-POST
Runoff = 1.50 cfs @ 12.00 hrs, Volume= 3,380 cf, Depth> 1.20"
Routed to Link 2L : POI#2-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
33,783 79 50-75% Grass cover, Fair, HSG C
33,783 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
8.4 100 0.0250 0.20 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
Subcatchment 2: 2-POST
Hydrograph
❑Runoff
1 1.50 cfs @ 12.00 hrsI
111111111 / Runoff=1.$0 ON @ 12.00 hrs
iiiiiii
/ Type II 24-hr
1yr Rainfall=3.02"
T
j j j i
i i i i i i
Runoff Vol me-3 3 0 f
,.-..Run�ff..Area...,. _af
3 Runoff;Depth>1.20"
O
Flow Length100'
Slope=0.0250 'I'
Tic=8.4 min
CN=79
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 5
Summary for Subcatchment 3: 3-BYPASS
Runoff = 2.59 cfs @ 12.01 hrs, Volume= 6,084 cf, Depth> 0.92"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
79,478 74 >75% Grass cover, Good, HSG C
79,478 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
7.1 100 0.0375 0.23 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
1.7 300 0.0350 3.01 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
8.8 400 Total
Subcatchment 3: 3-BYPASS
Hydrograph
D Runoff
L2.59 cfs @ 12.01 hrs
! ROnoff=2.59 cfs:@12.01 hrs
Type II 24-hr
--Rltnfan-3:
2-`
Runoff Area=79,478 Sf
/ Runoff Volume=6,084 cf
RunoffDepth>0.92"
u_ . Flow 1Length=400'
1 / Tc=8.8 min
' 1 1 I 1 I 1 1 1CN=74
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 6
Summary for Subcatchment 3A: 3A-OFFSITE
Runoff = 2.74 cfs @ 12.00 hrs, Volume= 6,223 cf, Depth> 1.53"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
12,888 98 Paved parking, HSG C
35,929 79 50-75% Grass cover, Fair, HSG C
48,817 84 Weighted Average
35,929 73.60% Pervious Area
12,888 26.40% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.4 100 0.0500 0.26 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
2.3 500 0.0500 3.60 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
8.7 600 Total
Subcatchment 3A: 3A-OFFSITE
Hydrograph
3— i i i D Runoff
[2.74cfs@1200hrsI
Runoff*2.74 cfs:@ 12.0Q hrs
/ ' Type II 24-hr
1yr Rainfall=3.02"
2— I 1 Runoff Area=48,817 sf
Runoff Volume=6,223 Of
v
Runoff;Depth>1.53"
o
LL Flow ',Length=600'
/ p
Sio a=0 0500 '/'
1—
Tc=8.7 min
CN 84
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 7
Summary for Subcatchment 3B: 3B-BYPASS
Runoff = 1.19 cfs @ 12.07 hrs, Volume= 3,346 cf, Depth> 1.20"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
33,514 79 50-75% Grass cover, Fair, HSG C
33,514 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
13.4 100 0.0200 0.12 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.64"
1.2 150 0.0200 2.12 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
14.6 250 Total
Subcatchment 3B: 3B-BYPASS
Hydrograph
❑Runoff
1.19cfs@12.07hrs
Runoff=1.19 cfs!@ 121.07 hrs
j
1- 1yr Rainfall= .02"
RunoffArea=33,514 of
I I Runoff Volume=3,346 cf
RunoffDepth>1.20"
LL / Flow Length=250'
Slope=0.0200 'I'
/ Tc=14.6i min
CN=79
/%///////// %// / / //
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02r"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 8
Summary for Subcatchment 3C: 3C-OFFSITE
Runoff = 12.74 cfs @ 12.14 hrs, Volume= 42,883 cf, Depth> 1.45"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
79,308 98 Paved parking, HSG C
274,469 79 50-75% Grass cover, Fair, HSG C
353,777 83 Weighted Average
274,469 77.58% Pervious Area
79,308 22.42% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
7.7 400 0.0300 0.87 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
4.1 300 0.0600 1.22 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
21.0 800 Total
Subcatchment 3C: 3C-OFFSITE
Hydrograph
Iitliflif 11
14 ❑Runoff
13 .7
. pioff�.1.21.74:,..cfS...{c�....1..�..'F.4...hrS.....
2.14 hrs ��
12='
._._....._1........................._............_i.......... ..... ...... ..... ..... ...... _._ ...... ..... ..... ...... ..... .....' - _..
' i 11-
10= -
_.... -1- -:. fir- atit a
• _
tt O u e 8 3
............ ..... ...._F 11111 hag
F#ow--Lengt 00
6 i
5- /+M'
Lid 83
3
1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 9
Summary for Subcatchment 4: BYPASS-4
Runoff = 3.82 cfs @ 11.97 hrs, Volume= 7,829 cf, Depth> 0.92"
Routed to Link 4L : POI#4-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
102,130 74 >75% Grass cover, Good, HSG C
102,130 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 4: BYPASS-4
Hydrograph lllllll
❑Runoff
4—.. 1 3.82 cfs @ 11.97 hrs i
Runoffs3.82 cfs'@ 11.97 hrs
Type II 24-hr
3 1yr Rainfalt=3.0
11 I :Runoff Area=102,130 sf
Runoff Volume=7,829 Of
2 / Runoff Depth>0.92"
LL Tc=5.0 mi'n
CN=74
1-
� , , , , , , , , , , ..
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 10
Summary for Subcatchment 4A: 4-OFFSITE
Runoff = 7.23 cfs @ 11.96 hrs, Volume= 14,689 cf, Depth> 1.03"
Routed to Link 4L : POI#4-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
14,354 98 Paved parking, HSG C
157,226 74 >75% Grass cover, Good, HSG C
171,580 76 Weighted Average
157,226 91.63% Pervious Area
14,354 8.37% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 4A: 4-OFFSITE
Hydrograph
8=. ■Runoff
7.23cfs@l1.96hrsiiiiiiiiiii
r Runoff7.23-cfs @ 11.90hrs
6- 1yr Rainfall=3.02"
....:.....
Runoff ; rei-
_ RunoffValume=14,689 cf
4 Runoff Depth>1 03"....
O - /
CN=76
2- I Ii
i- i
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type 1124-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 11
Summary for Subcatchment DA1: DRAINGE AREA#1
Runoff = 20.07 cfs @ 12.09 hrs, Volume= 59,307 cf, Depth> 1.60"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
205,018 98 Paved parking, HSG C
240,195 74 >75% Grass cover, Good, HSG C
445,213 85 Weighted Average
240,195 53.95% Pervious Area
205,018 46.05% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
4.8 100 0.1000 0.35 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
6.3 600 0.1000 1.58 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
1.2 280 0.0350 3.80 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.5 354 0.0055 3.90 4.79 Pipe Channel, RCP_Round 15"
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
1.4 437 0.0050 5.09 16.00 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50'
n= 0.013
1.0 370 0.0050 5.91 29.00 Pipe Channel, RCP_Round 30"
30.0" Round Area= 4.9 sf Perim= 7.9' r= 0.63'
n= 0.013
0.4 144 0.0050 6.67 47.16 Pipe Channel, RCP_Round 36"
36.0" Round Area= 7.1 sf Perim= 9.4' r= 0.75'
n= 0.013
16.6 2,285 Total

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02r"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 12
Subcatchment DA1: DRAINGE AREA#1
Hydrograph
22 ,........._.............._.,..........._.,............_,..............,............_..............,..............,......... ■Runoff
214' ,............................_............_..................................... 20.07 cfs 12.09 hrs 20; .
.. ......................................, ........................................_............_.................... Runoff 20.07 cf$ @ 12.09 hrs
19= ......._............_«..........................._..............«............_............_...............«......
1124-hr
,..... yr ark a
15=' . _........................._............................................_........................._.............._......................... Run Off=Area-445,213 sf
w 13 :
_._ Runoff Volume_ 59,307 of
.13 12=- . ....__..........._.,..........._.............._..........................._............_............... .. ,...... Runoff Depth>1 64".._.
11=
10= Flow.-.len�� th=2285'
LL g
9' .: ..................................._........................ _
� Tc-1-6 6 min
74/1; I 1 ! I ! 1 ! ! i ! OS ! I ! I ! ! I ICI$45
----- -
5 --i-
q
3 b.........
%i
2
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 13
Summary for Subcatchment OS:1: OFFSITE DA#1
Runoff = 4.59 cfs @ 12.15 hrs, Volume= 15,583 cf, Depth> 1.52"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
88,182 79 50-75% Grass cover, Fair, HSG C
34,493 98 Paved parking, HSG C
122,675 84 Weighted Average
88,182 71.88% Pervious Area
34,493 28.12% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
4.8 100 0.1000 0.35 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
1.6 600 0.1000 6.42 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
15.0 Direct Entry,
21.4 700 Total
Subcatchment OS:1: OFFSITE DA#1
Hydrograph
5— ' •Runoff
14.59 cfs @ 12.15 hrs
- Runoff=4.59 cfs:@ 12.15 hrs
4—
i
' — 02„....
ype �"
_ � 1yr Ra'nfal1-3.
r Runoff Area 1 22,675 f
w 3— Runoff Volume- 15,583 Of
-
0i Runoff:Depth>1''.52"
0
LL 700'__.
tow-:Length
2
- Slope=0.1000 '1'
1 =
C '
1-- Ii111111i3O .
CN 84
o . ..
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 14
Summary for Subcatchment OS:2: OFFSITE DA#2
Runoff = 4.40 cfs @ 12.17 hrs, Volume= 15,729 cf, Depth> 1.32"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
18,400 98 Paved parking, HSG C
124,553 79 50-75% Grass cover, Fair, HSG C
142,953 81 Weighted Average
124,553 87.13% Pervious Area
18,400 12.87% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
2.0 300 0.0450 2.53 Sheet Flow,
Smooth surfaces n= 0.011 P2= 3.64"
6.0 400 0.0500 1.12 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
15.0 Direct Entry,
23.0 700 Total
Subcatchment OS:2: OFFSITE DA#2
Hydrograph
D Runoff
- Ili 14.40 cfs @ 12.17 hrs
� .-. _ iL
R unoff:44 Ocfs@p2.17hrs
4
Ty Pe 1124-h r
�� 1yr Rainfal1=3.02"
;Runoff Are6=142,953 -Of
3—
N Runoff'Volume=15,729 Of
' Runoff:Depth>1''.32"
- - 1
LL 2� II . en gth=700'
3
ow
� Tc= .0 min
CN=81
1 i
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 15
Summary for Subcatchment OS:3: OFFSITE DA#3
Runoff = 0.48 cfs @ 12.14 hrs, Volume= 1,602 cf, Depth> 1.26"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 1yr Rainfall=3.02"
Area (sf) CN Description
512 98 Paved parking, HSG C
14,769 79 50-75% Grass cover, Fair, HSG C
15,281 80 Weighted Average
14,769 96.65% Pervious Area
512 3.35% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
15.0 Direct Entry,
20.0 0 Total
Subcatchment OS:3: OFFSITE DA#3
Hydrograph
0 Runoff
0.57:''rt 1 0.48 cfs a 12.14 hrs
........................._......................................._.............. ..... c►fF- 0s48...cfs @ 1..2..1.4 hrs........
0.45
Type 1124-h r
0.4_ 1 r Rainfall=3.02"
y
0.35= RU.-..-.n0 ea 5.._ ,ff Ar =1 2 81...-._._f_._...
•
w 03-� i
i
......... ....
uno • o ume ;, c
.
epth
0025-� ?
- I j
T-c=2.0..0..min.-..
0.2= ' C0
N=80
0.15
0.1. i
' 4��
0.05_'
///�/////////////////////��
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 16
Summary for Subcatchment 1 B: BYPASS-1
Runoff = 10.20 cfs @ 11.98 hrs, Volume= 21,510 cf, Depth> 2.62"
Routed to Link 1L : POI#1-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
98,576 74 >75% Grass cover, Good, HSG C
98,576 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.4 100 0.0500 0.26 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
Subcatchment 1 B: BYPASS-1
Hydrograph
111 1 ' ' ' ■Runoff
- ...........-------.....-------...._1.------.......------......------.._i...----- ---. ..... .20 hrs ..... .........
10 cfs 11.98 ��_
10 ,. Runof =p10 20 cfs © 11.90 hrs
T eII
9_ yp r
_.... ..._i.... --10yr Oatnfall-5 32"
8
Runoff.Area
77 V 1 1 Runoff Volum_ e=21,510 cf
6 Runoff Depth>2.62"...
o ..----- -. ....Flow..-Length=l0
u. 5_-
............-+----........-+---.......-I--......--+..----- --- --- ---- ---- i ...... ..... ..... ...... ..... p = ......
4-'
= . ._...-- ----4----I-----i--------- .......
T.c....& 4...m.i.n
s_ ' 0CIS=74
2.1 -- , 111111 ! 1 ! &,,,,,, 11111111 !
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 17
Summary for Subcatchment 2: 2-POST
Runoff = 3.82 cfs @ 12.00 hrs, Volume= 8,653 cf, Depth> 3.07"
Routed to Link 2L : POI#2-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
33,783 79 50-75% Grass cover, Fair, HSG C
33,783 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
8.4 100 0.0250 0.20 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
Subcatchment 2: 2-POST
Hydrograph
.........................._i.........._............_i.........._ ..... •Runoff
4—.. 13 82 cfs @ 12 00 hrs I
- / Runoffr3.82 cfs;@12.00 hrs
/ Type II 24-hr
.11.
3 ayr Re�rfall=5 32"
Runoff Area=33,783 of
N _ Runoff Volume=0,653 Of
2— ..... / Runoff Depth>3.07"
LL Flow ;Length*100'
_ // I Slope=0.0250IM 'I'
Ttc
CN=79
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 18
Summary for Subcatchment 3: 3-BYPASS
Runoff = 7.60 cfs @ 12.00 hrs, Volume= 17,331 cf, Depth> 2.62"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
79,478 74 >75% Grass cover, Good, HSG C
79,478 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
7.1 100 0.0375 0.23 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
1.7 300 0.0350 3.01 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
8.8 400 Total
Subcatchment 3: 3-BYPASS
Hydrograph
.........._.,..........._............._............. ............_L.......- ■Runoff.
$-" L7.6ocfs@12.00hrsf
f..... : ....R.Ianoff=7.00. ...�. s..�.1�..OQ....h.rs
7 Type I 124-h r
1 Oy
6- r Ra rnfall-a........ ;
RunoffArea=79 478 of
N 5_"
Runoff Volume=17,331 cf
-
.82."
0 4 i�epth>
.._,..... ....;.....Run-off; 2.
LL = iiiiiiiii I IFIONILeOgth*4001
3-; / H H ITO=0.81min
2= 's
1
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 19
Summary for Subcatchment 3A: 3A-OFFSITE
Runoff = 6.21 cfs @ 12.00 hrs, Volume= 14,476 cf, Depth> 3.56"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
12,888 98 Paved parking, HSG C
35,929 79 50-75% Grass cover, Fair, HSG C
48,817 84 Weighted Average
35,929 73.60% Pervious Area
12,888 26.40% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.4 100 0.0500 0.26 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
2.3 500 0.0500 3.60 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps _
8.7 600 Total
Subcatchment 3A: 3A-OFFSITE
Hydrograph
•Runoff
�6.21 cfs @ 12.0o hrs Iiiiii
6-
Runoff=6 21 cfs @ 12.00 hrs
-
TypeII24hr
5- 111111111 ' 10yr Rainfall=5 32"
_ RunoffArea=48,817 sf
N 4 I I Runoff'Volume=14,476 cf
Depth> 56"._._..
' Runoff 3
II 3_ FlowLength=600'
S ode 0.0500 :L'
2= Tc=8.7 min
-
1- � CN 8
%%/i
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 20
Summary for Subcatchment 3B: 3B-BYPASS
Runoff = 3.08 cfs @ 12.07 hrs, Volume= 8,570 cf, Depth> 3.07"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
33,514 79 50-75% Grass cover, Fair, HSG C
33,514 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
13.4 100 0.0200 0.12 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.64"
1.2 150 0.0200 2.12 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
14.6 250 Total
Subcatchment 3B: 3B-BYPASS
Hydrograph
•Runoff
o.............i.............«............. 1 13.08 cfs @ 12.07 hrs I
3- 1 1 1 1Runoff=3.08 'Ofsl @ 12.07 hrs
- 1111 11111TypeII 24-hr
1,0yr Rainfall=5.32"
Runoff Area=33,514 sf
N 2 1H1H Runoff Volume=8,570 cf
- 1 1 1 1 1 1 1 1 1 Runoff:Depth>3.07"
LL / Flow Length=250'
- Slope=0.0200
........ ....
/ Tc=14.6 min CN=79
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 21
Summary for Subcatchment 3C: 3C-OFFSITE
Runoff = 30.14 cfs @ 12.14 hrs, Volume= 101,678 cf, Depth> 3.45"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
79,308 98 Paved parking, HSG C
274,469 79 50-75% Grass cover, Fair, HSG C
353,777 83 Weighted Average
274,469 77.58% Pervious Area
79,308 22.42% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
7.7 400 0.0300 0.87 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
4.1 300 0.0600 1.22 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
21.0 800 Total
Subcatchment 3C: 3C-OFFSITE
Hydrograph iiiiiiiiiii
lllllll
32=
L El Runoff
....._ -- --- ---- ---- --- ---- --- --- 30.14 ors @ 12.14 hrs I..._---....._-----.......... ...... ..._ ..... ...... ..... ...... ...... .........
30_ Run.©. f-t3.0_.1.4...cfs...a7....1. .1.4..-hrs.-..-..
28='
24= i /
i
22=_ ' I I i i I IunpA.rea=i353,777..sf..-
11111
20=' un,........
Roff Volurne=1101 678 cf
18 > ... .$." ..._.- .Ru-nof.#...D.epth>34. ...
0 16 1 1 1 1 1 // h8 01
u. 14=`
:
12
10 C _$.3.-...
8
61111111114
4 s. I 1 i
2 `
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 22
Summary for Subcatchment 4: BYPASS-4
Runoff = 11.06 cfs @ 11.96 hrs, Volume= 22,295 cf, Depth> 2.62"
Routed to Link 4L : POI#4-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
102,130 74 >75% Grass cover, Good, HSG C
102,130 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 4: BYPASS-4
Hydrograph
�........ I-----+----
12 ■Runoff
......- -- --- ---- ---- --- ---- --- ..._ 11.06 cfs 11�96 hrs ........ ---. ..... ...... ..... ..... ...... ..... ...... ...... .........
11 fft-1
R....
unQ 1.Ofi cfs g 11.96 hrs
1(:) -- -- -- i.-.T..._pe-0ll_24-hr
1111111 y
9_/ 1111111Oyr Rainfall=5.32
t
r• *1O2,-11' ef
8='
=2 4�29.5....cf.....
;.... ....�
:_.. ..Runoff D p#h>2.6 3 6
o
5- 1 j i 111111 CAI= 4
4-
3 /
2
i
II
1 //%//////%////////////////%�������/
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 23
Summary for Subcatchment 4A: 4-OFFSITE
Runoff = 19.79 cfs @ 11.96 hrs, Volume= 40,020 cf, Depth> 2.80"
Routed to Link 4L : POI#4-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
14,354 98 Paved parking, HSG C
157,226 74 >75% Grass cover, Good, HSG C
171,580 76 Weighted Average
157,226 91.63% Pervious Area
14,354 8.37% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 4A: 4-OFFSITE
Hydrograph
22
•Runoff
21
I 19.79cfs@l1.96hrsjiiiiiiiiii
20:
;......RUnOff.19.79 cf1.... . ....1..1.90
18, :............ ..... I
..... ....... T e II 24-hr.....
-O.yr..Rainfal1=5:32".....
15
i
Ruhofl Volume=40 020 cf ...
N = I
t> 12- Runoff:Depth>2.80"
V of11111111 ,
i17c=5.0, min
C =76
6- ..................................._............................_........................._.........................._I__
iiiiiiiii
5 __......._.........................._...................................
1
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type 1124-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 24
Summary for Subcatchment DA1: DRAINGE AREA#1
Runoff = 45.13 cfs @ 12.09 hrs, Volume= 135,503 cf, Depth> 3.65"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
205,018 98 Paved parking, HSG C
240,195 74 >75% Grass cover, Good, HSG C
445,213 85 Weighted Average
240,195 53.95% Pervious Area
205,018 46.05% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
4.8 100 0.1000 0.35 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
6.3 600 0.1000 1.58 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
1.2 280 0.0350 3.80 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.5 354 0.0055 3.90 4.79 Pipe Channel, RCP_Round 15"
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
1.4 437 0.0050 5.09 16.00 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50'
n= 0.013
1.0 370 0.0050 5.91 29.00 Pipe Channel, RCP_Round 30"
30.0" Round Area= 4.9 sf Perim= 7.9' r= 0.63'
n= 0.013
0.4 144 0.0050 6.67 47.16 Pipe Channel, RCP_Round 36"
36.0" Round Area= 7.1 sf Perim= 9.4' r= 0.75'
n= 0.013
16.6 2,285 Total

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 25
Subcatchment DA1: DRAINGE AREA#1
Hydrograph
50i. .. _...- * .._- ....... ._..._ _._.. .._._. ... ......
■Runoff
481 13cf @ 2.09h _
46 « i i
1
5
381 ,, 1... rfatnfatt=5.32
34 ',. ..........:.............._.............................:...........................a............_.................... .......Runoff;Area=;445,213 if
301 .. ........_..............«............................,......................................._..........1H I. Runoff Volume=135,503 cf.._.
-- 26' : Run-off Depth>3.65" ._.
b 2,28 J__.....
20=' ... ......._..........................._....................................... _
_ 16Gmn-
18- I
r
/L 12 •
6 /
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 26
Summary for Subcatchment OS:1: OFFSITE DA#1
Runoff = 10.61 cfs @ 12.14 hrs, Volume= 36,269 cf, Depth> 3.55"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
88,182 79 50-75% Grass cover, Fair, HSG C
34,493 98 Paved parking, HSG C
122,675 84 Weighted Average
88,182 71.88% Pervious Area
34,493 28.12% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
4.8 100 0.1000 0.35 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
1.6 600 0.1000 6.42 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
15.0 Direct Entry,
21.4 700 Total
Subcatchment OS:1: OFFSITE DA#1
Hydrograph
•Runoff
11 1 1 1 1 1 1 1 1 I10.61 cfs @ 12.14 hrs I
- , ------ ----�----� -- - __Ron-Off*-101.64}c#5_{c�_..1..2.44-Mrs--
10
i
'/ 1 1 1 1 110Yr Rainfall=5.32"
8= 1 1 1 1 1 1 1 1 1 1 I RunoffArea=i122,675 sf
7 // Runoff Volume=36,269 cf
v i
i i i i i i i i kurjoff D y
6-
1F
#ow-Len
LL 5-,
i i
4-' �
i
i i
i
:1.................................................................................................................................................................................... N
-
8
i_ /i
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 27
Summary for Subcatchment OS:2: OFFSITE DA#2
Runoff = 10.95 cfs @ 12.16 hrs, Volume= 38,744 cf, Depth> 3.25"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
18,400 98 Paved parking, HSG C
124,553 79 50-75% Grass cover, Fair, HSG C
142,953 81 Weighted Average
124,553 87.13% Pervious Area
18,400 12.87% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
2.0 300 0.0450 2.53 Sheet Flow,
Smooth surfaces n= 0.011 P2= 3.64"
6.0 400 0.0500 1.12 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
15.0 Direct Entry,
23.0 700 Total
Subcatchment OS:2: OFFSITE DA#2
Hydrograph
12 1H ■Runoff
..--;-..- .._;.-..- -..-;.-.. ...- 70 5 cfs 12.16 hrsI.........:..... ....;..-. ..-_;...- ..-.;-..--
11'
_ Ru n4ff. 10.95 cfs 12.16 hrs
10
4-
11111i 1Typel II 24-hr
9= . I I I I I I I I I I 1111 110YrRakifall=5.32"..-
8 -
............................. . .... .
:...........:..............
uno reap s
C =38,744....ef......
_
-Depth>3.25-....
6=
Flow.-.Le n g#h 7 0 0'_._..
LL 5_- Tc=23.O min
1111111111 0I I I I I I I I I CM=81
3_
2-
i i '
1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 28
Summary for Subcatchment OS:3: OFFSITE DA#3
Runoff = 1.23 cfs @ 12.13 hrs, Volume= 4,023 cf, Depth> 3.16"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 10yr Rainfall=5.32"
Area (sf) CN Description
512 98 Paved parking, HSG C
14,769 79 50-75% Grass cover, Fair, HSG C
15,281 80 Weighted Average
14,769 96.65% Pervious Area
512 3.35% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
15.0 Direct Entry,
20.0 0 Total
Subcatchment OS:3: OFFSITE DA#3
Hydrograph
❑Runoff
11.23 cfs @12.13 hrs I
Runoff=1.23 cfs @ 12.13 hrs
Type II 24-hr
1- 10yr Rainfall=5.32"
Runoff'Area=15,281 sf
Runoff Volume=4,023 cf
Runoff:Depth>3.16"
LL Tc=20.0 min
CN=80
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 29
Summary for Subcatchment 1 B: BYPASS-1
Runoff = 19.10 cfs @ 11.98 hrs, Volume= 41,076 cf, Depth> 5.00"
Routed to Link 1L : POI#1-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
98,576 74 >75% Grass cover, Good, HSG C
98,576 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.4 100 0.0500 0.26 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
Subcatchment 1 B: BYPASS-1
Hydrograph
....i.... ..._.... Runoff
20- "",.........._............._............_............_.......... 19.10 cfs 11.98 hrs ........
19_-
....:.....
Ron ff. 19.19-cf@ 11.9 hrs
17 ; Type II....24-hr......
16
.... .....i . .yrgathfall=8.-09"
14, : -_.... ....... .... .._. Runoff"Area_.._.9.8,576sf...
13=
12=
. _ - �/13�U�f'1'1e........................_....................................................................._.................... i ..... ku11Off Depth>5
0'
LL ? 1
ow........en9t ;
:'
i
n....
CIS 744 .
i
3 ' ............ /
i
/
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 30
Summary for Subcatchment 2: 2-POST
Runoff = 6.78 cfs @ 11.99 hrs, Volume= 15,718 cf, Depth> 5.58"
Routed to Link 2L : POI#2-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
33,783 79 50-75% Grass cover, Fair, HSG C
33,783 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
8.4 100 0.0250 0.20 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
Subcatchment 2: 2-POST
Hydrograph
lllllllllllllllllllllll- ■Runoff
7_" 1 6.78 cfs @ 11.99 hrs
r 1 Runoff=6.78 cfs'@ 11'.99 hrs
6-'
Type II 24 hr
llllllllllllll
_1a0yr Reir�fall 8.09"
5- Runoff Arya33,783 Sf y = ..-.. Runoff-:VoIume=15.7 l8.... f......
3 4 Runoff;Depth>5.58"
LL gth .0.0 ....
3 l i
I
o e*0 '0 50 'I'
w-
' � � p — 2
2: "
CN=79
1_
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 31
Summary for Subcatchment 3: 3-BYPASS
Runoff = 14.32 cfs @ 12.00 hrs, Volume= 33,098 cf, Depth> 5.00"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
79,478 74 >75% Grass cover, Good, HSG C
79,478 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
7.1 100 0.0375 0.23 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
1.7 300 0.0350 3.01 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
8.8 400 Total
Subcatchment 3: 3-BYPASS
Hydrograph
16-
1 flitRunoff
15= 114.32 cfs 12.00 hrs l._..
14- Runoffr14.32 cfs@ 12.00 hrs
13_ :. .........:.............._..............;..............;.........................._............_............_,..............;..............: 1111111TypellI44ir__..
12- _
09 OO.�r.Ftai.nfall 8. ..,...n
11= _
---......._..........................._............................1......... ...... ..... ..... ...... __..... ...... ..... ...- Ruiloff - -...
w 9-
... ....Ru .a .. ep.D t
."
n f# h 5.
.
00
............_ •
............... ..... _...... � _.....Flow...Length 4.0.01.......
u_ 7-
6 Tc
=8.8min
4IIIIIIII1X11111111111
3
i .
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 32
Summary for Subcatchment 3A: 3A-OFFSITE
Runoff = 10.47 cfs @ 12.00 hrs, Volume= 25,109 cf, Depth> 6.17"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
12,888 98 Paved parking, HSG C
35,929 79 50-75% Grass cover, Fair, HSG C
48,817 84 Weighted Average
35,929 73.60% Pervious Area
12,888 26.40% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
6.4 100 0.0500 0.26 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
2.3 500 0.0500 3.60 Shallow Concentrated Flow,
Unpaved Kv= 16.1 fps
8.7 600 Total
Subcatchment 3A: 3A-OFFSITE
Hydrograph
.......... Runoff
11 110.47cfs@12.00hrsl
10;.' I I r
. 1OO.yr I�ai� all $.09_
8- Runoff Area=48,817 sf
7 Runoff Volume=25,109 Of
6- epth 7'•....
- LS140=01,0500 IT
4-' 1 1 1i
Tc=8.7 min
, , , , , , , , , 41 1 1 1 1 1 !
3- —
CN- 4
2_
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 33
Summary for Subcatchment 3B: 3B-BYPASS
Runoff = 5.50 cfs @ 12.06 hrs, Volume= 15,570 cf, Depth> 5.58"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
33,514 79 50-75% Grass cover, Fair, HSG C
33,514 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
13.4 100 0.0200 0.12 Sheet Flow,
Grass: Dense n= 0.240 P2= 3.64"
1.2 150 0.0200 2.12 Shallow Concentrated Flow,
Grassed Waterway Kv= 15.0 fps
14.6 250 Total
Subcatchment 3B: 3B-BYPASS
Hydrograph
--- i
6-y i I 11 I i I ■Runoff
11 L5.5o cfs @ 12.06 hrs I
Runoff*5.50 cfs 12.06 hrs
5-',. Type II 24-hr
/ i i100yi• Rainfall=8.09"
4- I I R'unoffArea-33,514 sf
RunoffVolume=15,570 Of
3- RunoffDepth>5.58
u_ ' :Flow :Length=250'
o _
2 _
pe;
Tc=14.6 min
1
o _/%iiii%//%iiiiiiiii�i� %/%///ice ////
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 34
Summary for Subcatchment 3C: 3C-OFFSITE
Runoff = 51.76 cfs @ 12.13 hrs, Volume= 178,000 cf, Depth> 6.04"
Routed to Link 3L : POI#3-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
79,308 98 Paved parking, HSG C
274,469 79 50-75% Grass cover, Fair, HSG C
353,777 83 Weighted Average
274,469 77.58% Pervious Area
79,308 22.42% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
9.2 100 0.0200 0.18 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
7.7 400 0.0300 0.87 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
4.1 300 0.0600 1.22 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
21.0 800 Total
Subcatchment 3C: 3C-OFFSITE
Hydrograph lllllllllll
lllllll
55 I ; j El Runoff
151 z13
.76cfs@1hrs I
50
,._. ....,_ 1, ,. Ru nOff: 51.70 cfS.-.�.-..OA.S._N's...
....
- T ..etf.... 4-hr
J
45-
iiii
_
I 0©n
40= _
` 353,777sf_..
Runoff Arearn
35 I RunoffVolurle=178,000 cf
30- Runoff Depth>6 04."
........-.. Flow L ng h=800.........
E 25-'
1
. 1 ,_.. .... 1 0 min
...........
20
15 `
10_
1 's
i
o= //
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 35
Summary for Subcatchment 4: BYPASS-4
Runoff = 20.73 cfs @ 11.96 hrs, Volume= 42,572 cf, Depth> 5.00"
Routed to Link 4L : POI#4-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
102,130 74 >75% Grass cover, Good, HSG C
102,130 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 4: BYPASS-4
Hydrograph
2 ....=' .........._...
......._............_I............_............. .........
3 •Runoff
22 i »..........
20 73 cfs @ 11 96 hrs fill
21', off=20 73cfS @11.96 h is ._..
204 ; : . ? un
19=' :...._..... .....? ....I _...._ .. i... .:.... ...... _..
- Type;lf....�4-hr.
_;
17 ; 1.0.O.yr....Fta.infall.......8.09..
16 '
.............a............_..........._:...... kfO . e2�1
15= Runoff:Are 0. 30 f
14=' ._._.......i.........................._l. p
42,572-Of..
12- + .....+ ...._; ;.. .......;.. ....._;... ...._;.... .....;.... ..._:..... ........ _.......... I. I RuOoff Depth>5.00"
......
c 11=
LT_ 10E 1 se it 'll
9= C11=74.....
6
,
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 36
Summary for Subcatchment 4A: 4-OFFSITE
Runoff = 36.21 cfs @ 11.95 hrs, Volume= 74,860 cf, Depth> 5.24"
Routed to Link 4L : POI#4-POST
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
14,354 98 Paved parking, HSG C
157,226 74 >75% Grass cover, Good, HSG C
171,580 76 Weighted Average
157,226 91.63% Pervious Area
14,354 8.37% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 4A: 4-OFFSITE
Hydrograph
..............................._............._.........................._i............_............_........... ......
_i.. •Runoff
38 5. .......... .....< -.. 95
-._..... ............I 36.21cfs @ 11. hrs�-..- --
,.... ... _ _......R#.1 offt-'3G21--cfs 11 firs
! i
32= ...............................,..............,.............._.............a..............,............................, / -
30= _ .... 100.yr Rainfall..=$ 09'.-......
28= :._._..-.. ..-.. A rea*1.-71.-,5$0-..sf..-...
i i Runoff
p QC s
24= R-u-n-o-�.-.voI-u. -e.=.7.4�860.-..cf-..-...
22='' ......................................._....................................................._.........................._. ...... 2 '!........
-..
=
i i 1
/
LL 18= - - . .--.. - -._.. fic::--_5.�-min.-..
1.
12
10=
_. r �////
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type 1124-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 37
Summary for Subcatchment DA1: DRAINGE AREA#1
Runoff = 75.72 cfs @ 12.08 hrs, Volume= 232,997 cf, Depth> 6.28"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
205,018 98 Paved parking, HSG C
240,195 74 >75% Grass cover, Good, HSG C
445,213 85 Weighted Average
240,195 53.95% Pervious Area
205,018 46.05% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
4.8 100 0.1000 0.35 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
6.3 600 0.1000 1.58 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
1.2 280 0.0350 3.80 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
1.5 354 0.0055 3.90 4.79 Pipe Channel, RCP_Round 15"
15.0" Round Area= 1.2 sf Perim= 3.9' r= 0.31'
n= 0.013
1.4 437 0.0050 5.09 16.00 Pipe Channel, RCP_Round 24"
24.0" Round Area= 3.1 sf Perim= 6.3' r= 0.50'
n= 0.013
1.0 370 0.0050 5.91 29.00 Pipe Channel, RCP_Round 30"
30.0" Round Area= 4.9 sf Perim= 7.9' r= 0.63'
n= 0.013
0.4 144 0.0050 6.67 47.16 Pipe Channel, RCP_Round 36"
36.0" Round Area= 7.1 sf Perim= 9.4' r= 0.75'
n= 0.013
16.6 2,285 Total

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 38
Subcatchment DA1: DRAINGE AREA#1
Hydrograph
iiiiiiiiiiiiiiiiiiiiii ■Runoff
80= . . ..............................t-.-..-.. -..-.. -..-. _. 75 72 cfs @ 12.08 hr
75= h __.-.._._ ....Ru ngff=.75 72....cfs....Q..12.08 h rs
70=
I.
;OOyr i�ainfati $. 9
55 Runoff Area=445,213 sf
y 50_
" Runoff Volume=232,997 Of
.Y. 45=' / "
_.... .-_..-.. �.u.noff.-.Dep
th>5.29...
40
-.. _i c 285--
u. 35_:- 1
C-46• 1 min
30= // /+
25=" I I 1 I
20 •
15
10
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 39
Summary for Subcatchment OS:1: OFFSITE DA#1
Runoff = 18.04 cfs @ 12.14 hrs, Volume= 62,925 cf, Depth> 6.16"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
88,182 79 50-75% Grass cover, Fair, HSG C
34,493 98 Paved parking, HSG C
122,675 84 Weighted Average
88,182 71.88% Pervious Area
34,493 28.12% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
4.8 100 0.1000 0.35 Sheet Flow,
Grass: Short n= 0.150 P2= 3.64"
1.6 600 0.1000 6.42 Shallow Concentrated Flow,
Paved Kv= 20.3 fps
15.0 Direct Entry,
21.4 700 Total
Subcatchment OS:1: OFFSITE DA#1
Hydrograph
20-' .............................
•Runoff
19 ---..._----- ----- ---- 1: * i �s.aa cfs . 1214
18= F 1
__--Runoff*-10,04 eft... . __17:4 -his
Type 11.._24-hr....
15' .._.... = 100Yr-Rainfall=$.09"._....
....:.... .._:.... ....:..
Ru
noff A rea122,6.75... f....
12= RU .Qf. /Ol.uC11 ......�. ,925....cf.......
- -Ru o E}' t .1
10- 1111
ep h G 6
LL 9_' - Flow Length0700'_._.
8= a=0 1000 I11111111110
Sl .p .
2'14mn._.
1 23 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 40
Summary for Subcatchment OS:2: OFFSITE DA#2
Runoff = 19.25 cfs @ 12.15 hrs, Volume= 69,085 cf, Depth> 5.80"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
18,400 98 Paved parking, HSG C
124,553 79 50-75% Grass cover, Fair, HSG C
142,953 81 Weighted Average
124,553 87.13% Pervious Area
18,400 12.87% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
2.0 300 0.0450 2.53 Sheet Flow,
Smooth surfaces n= 0.011 P2= 3.64"
6.0 400 0.0500 1.12 Shallow Concentrated Flow,
Woodland Kv= 5.0 fps
15.0 Direct Entry,
23.0 700 Total
Subcatchment OS:2: OFFSITE DA#2
Hydrograph
•Runoff
....... ..... ...... ...... ..... ..... ...... ..... .... ..1 .z 12.1 hrs .. ..... ...... ...... ..... ..... ._._ ._.. .._.. _._. ..........
20- .... .._,.... .._..... .......... ....«.... ........ � s s cfs @ s �
19= _ 1.9
_.---Bonoff= 2 5-cfs 1.;.1 -hra....
hr
17 i. .
i
. �
i _ _ _ 100 r II
14 / 1unoff Aea!1a 8 © n
42,953 sf.._...
134 1111 ! ! ! 111 /.
12=
69U85 cf
=
« Runoff De pth>5.80"...
i-..-..-.._
3
0 10_ ;............_:.............._......................... / F OW L n gth,700'
. _-
: Tc 230 min
7= ......... .... =$1 CN ....
5 f i
3
1
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 41
Summary for Subcatchment OS:3: OFFSITE DA#3
Runoff = 2.19 cfs @ 12.12 hrs, Volume= 7,240 cf, Depth> 5.69"
Routed to Pond SCM : STORMWATER WETLAND
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Type II 24-hr 100yr Rainfall=8.09"
Area (sf) CN Description
512 98 Paved parking, HSG C
14,769 79 50-75% Grass cover, Fair, HSG C
15,281 80 Weighted Average
14,769 96.65% Pervious Area
512 3.35% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
15.0 Direct Entry,
20.0 0 Total
Subcatchment OS:3: OFFSITE DA#3
Hydrograph
0 Runoff
12.19 cfs. 12.12 hrs l
1:4unofft-2.19 cfs Q1Z.1Z hrs
2- ` I I H I Type 1124-h r
100yr Rainfall=8.09"
Runoff Area=15,281 of
- 111111111 H Runoff Volume=7,240 Of
3 Runoff;Depth>5.69"
1- Tcc20 0..mjn...
CN=80
•
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type 1124-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 1
Summary for Link 1 L: POI#1-POST
Inflow Area = 824,698 sf, 31.34% Impervious, Inflow Depth > 1.13" for 1yr event
Inflow = 7.73 cfs @ 12.48 hrs, Volume= 77,602 cf
Primary = 7.73 cfs @ 12.48 hrs, Volume= 77,602 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 2L: POI#2-POST
Inflow Area = 33,783 sf, 0.00% Impervious, Inflow Depth > 1.20" for 1yr event
Inflow = 1.50 cfs @ 12.00 hrs, Volume= 3,380 cf
Primary = 1.50 cfs @ 12.00 hrs, Volume= 3,380 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 3L: POI#3-POST
Inflow Area = 515,586 sf, 17.88% Impervious, Inflow Depth > 1.36" for 1yr event
Inflow = 16.62 cfs @ 12.08 hrs, Volume= 58,537 cf
Primary = 16.62 cfs @ 12.08 hrs, Volume= 58,537 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 4L: POI#4-POST
Inflow Area = 273,710 sf, 5.24% Impervious, Inflow Depth > 0.99" for 1yr event
Inflow = 11.05 cfs @ 11.96 hrs, Volume= 22,518 cf
Primary = 11.05 cfs @ 11.96 hrs, Volume= 22,518 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 5L: POST DEV. TOTAL
Inflow Area = 1,647,777 sf, 22.15% Impervious, Inflow Depth > 1.18" for 1yr event
Inflow = 29.40 cfs @ 12.00 hrs, Volume= 162,037 cf
Primary = 29.40 cfs @ 12.00 hrs, Volume= 162,037 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs

STEWARTS GROVE SUBDIVISION
SCM-POST Type 1124-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 2
Summary for Link 1 L: POI#1-POST
Inflow Area = 824,698 sf, 31.34% Impervious, Inflow Depth > 3.08" for 10yr event
Inflow = 46.89 cfs @ 12.15 hrs, Volume= 211,901 cf
Primary = 46.89 cfs @ 12.15 hrs, Volume= 211,901 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 2L: POI#2-POST
Inflow Area = 33,783 sf, 0.00% Impervious, Inflow Depth > 3.07" for 10yr event
Inflow = 3.82 cfs @ 12.00 hrs, Volume= 8,653 cf
Primary = 3.82 cfs @ 12.00 hrs, Volume= 8,653 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 3L: POI#3-POST
Inflow Area = 515,586 sf, 17.88% Impervious, Inflow Depth > 3.31" for 10yr event
Inflow = 41.05 cfs @ 12.07 hrs, Volume= 142,056 cf
Primary = 41.05 cfs @ 12.07 hrs, Volume= 142,056 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 4L: POI#4-POST
Inflow Area = 273,710 sf, 5.24% Impervious, Inflow Depth > 2.73" for 10yr event
Inflow = 30.85 cfs @ 11.96 hrs, Volume= 62,314 cf
Primary = 30.85 cfs @ 11.96 hrs, Volume= 62,314 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 5L: POST DEV. TOTAL
Inflow Area = 1,647,777 sf, 22.15% Impervious, Inflow Depth > 3.09" for 10yr event
Inflow = 93.51 cfs @ 12.10 hrs, Volume= 424,925 cf
Primary = 93.51 cfs @ 12.10 hrs, Volume= 424,925 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs

STEWARTS GROVE SUBDIVISION
SCM-POST Type 1124-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 3
Summary for Link 1 L: POI#1-POST
Inflow Area = 824,698 sf, 31.34% Impervious, Inflow Depth > 5.63" for 100yr event
Inflow = 100.19 cfs @ 12.18 hrs, Volume= 387,246 cf
Primary = 100.19 cfs @ 12.18 hrs, Volume= 387,246 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 2L: POI#2-POST
Inflow Area = 33,783 sf, 0.00% Impervious, Inflow Depth > 5.58" for 100yr event
Inflow = 6.78 cfs @ 11.99 hrs, Volume= 15,718 cf
Primary = 6.78 cfs @ 11.99 hrs, Volume= 15,718 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 3L: POI#3-POST
Inflow Area = 515,586 sf, 17.88% Impervious, Inflow Depth > 5.86" for 100yr event
Inflow = 71.85 cfs @ 12.06 hrs, Volume= 251,778 cf
Primary = 71.85 cfs @ 12.06 hrs, Volume= 251,778 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 4L: POI#4-POST
Inflow Area = 273,710 sf, 5.24% Impervious, Inflow Depth > 5.15" for 100yr event
Inflow = 56.94 cfs @ 11.95 hrs, Volume= 117,432 cf
Primary = 56.94 cfs @ 11.95 hrs, Volume= 117,432 cf, Atten= 0%, Lag= 0.0 min
Routed to Link 5L : POST DEV. TOTAL
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs
Summary for Link 5L: POST DEV. TOTAL
Inflow Area = 1,647,777 sf, 22.15% Impervious, Inflow Depth > 5.62" for 100yr event
Inflow = 184.65 cfs @ 12.00 hrs, Volume= 772,173 cf
Primary = 184.65 cfs @ 12.00 hrs, Volume= 772,173 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs

STEWARTS GROVE SUBDIVISION
SCM-POST Type 1124-hr lyr Rainfall=3.02"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 1
Summary for Pond SCM: STORMWATER WETLAND
Inflow Area = 726,122 sf, 35.59% Impervious, Inflow Depth > 1.52" for 1yr event
Inflow = 28.91 cfs @ 12.11 hrs, Volume= 92,221 cf
Outflow = 7.34 cfs @ 12.51 hrs, Volume= 70,050 cf, Atten= 75%, Lag= 23.9 min
Primary = 7.34 cfs @ 12.51 hrs, Volume= 70,050 cf
Routed to Link 1L : POI#1-POST
Secondary= 0.00 cfs @ 1.00 hrs, Volume= 0 cf
Routed to Link 1L : POI#1-POST
Routing by Dyn-Stor-Ind method, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs/ 3
Starting Elev= 538.00' Surf.Area= 11,323 sf Storage= 9,199 cf
Peak Elev= 540.35' @ 12.51 hrs Surf.Area= 20,443 sf Storage= 49,866 cf (40,668 cf above start)
Plug-Flow detention time= 213.5 min calculated for 60,719 cf (66% of inflow)
Center-of-Mass det. time= 79.9 min ( 917.4 - 837.5 )
Volume Invert Avail.Storage Storage Description
#1 536.00' 123,582 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
536.00 1,668 0 0
537.00 2,703 2,186 2,186
538.00 11,323 7,013 9,199
539.00 18,000 14,662 23,860
539.50 18,887 9,222 33,082
540.00 19,790 9,669 42,751
541.00 21,637 20,714 63,465
542.00 23,540 22,589 86,053
543.50 26,498 37,529 123,582
Device Routing Invert Outlet Devices
#1 Secondary 541.50' 24.0' long + 3.0 '/' SideZ x 16.0' breadth EMERGENCY SPILLWAY
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63
#2 Device 5 540.50' 48.0"x 48.0" Horiz. PRINCIPLE SPILLWAY C= 0.700
Limited to weir flow at low heads
#3 Device 5 539.25' 24.0"W x 12.0" H Vert. TEMPORARY POOL WEIR C= 0.600
Limited to weir flow at low heads
#4 Device 5 538.00' 1.7"Vert. PERMANENT POOL ORRIFICE C= 0.600
Limited to weir flow at low heads
#5 Primary 531.62' 24.0" Round OUTLET BARREL
L= 54.0' RCP, end-section conforming to fill, Ke= 0.500
Inlet/Outlet Invert= 531.62' /530.00' S= 0.0300 '/' Cc= 0.900
n= 0.013, Flow Area= 3.14 sf

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr lyr Rainfall=3.02r"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 2
Primary OutFlow Max=7.34 cfs @ 12.51 hrs HW=540.35' TW=0.00' (Dynamic Tailwater)
Lam=OUTLET BARREL (Passes 7.34 cfs of 42.07 cfs potential flow)
—2=PRINCIPLE SPILLWAY ( Controls 0.00 cfs)
—3=TEMPORARY POOL WEIR (Orifice Controls 7.23 cfs @ 3.61 fps)
—4=PERMANENT POOL ORRIFICE (Orifice Controls 0.11 cfs @ 7.27 fps)
Secondary OutFlow Max=0.00 cfs @ 1.00 hrs HW=538.00' TW=0.00' (Dynamic Tailwater)
L1=EMERGENCY SPILLWAY ( Controls 0.00 cfs)
Pond SCM: STORMWATER WETLAND
Inflow
//.......................................................................................................................................................................................................................................................................... E 1 28.91 cfs 12.11 hrs 1........_ Outflow
:Inflow Area-726,122 If. ❑Primary
32=" .........._III
...........,............,.........._<........._<............,.........._................. _ - - ❑Secondary
i
_ i now cfshrs
Outflow 734cfs@1251 hts
=
Prima' =7.34 cfs 12.51 hrs
26 ' /
S? cand' =0.00 .fs � 1.0 . hrs
35'
22= -. • _..._. ........ P.eak..El.eY' 540_ --
20=';' "%, .' i = 9, 0 to-lrage.....4 6-cf
y i : /'
w 18="
LL
12�- ;' .. ... 7.34 cfs @ 12.51 hrs
10 ; .............:............1............:.......................i............1......... ;........I 7.34 cfs @ 12.51 hrs .... _4P ///////
.00cfs@1.00hrs : N OW
/' /
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type 1124-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 3
Summary for Pond SCM: STORMWATER WETLAND
Inflow Area = 726,122 sf, 35.59% Impervious, Inflow Depth > 3.55" for 10yr event
Inflow = 66.60 cfs @ 12.10 hrs, Volume= 214,538 cf
Outflow = 45.04 cfs @ 12.24 hrs, Volume= 190,391 cf, Atten= 32%, Lag= 8.4 min
Primary = 45.04 cfs @ 12.24 hrs, Volume= 190,391 cf
Routed to Link 1L : POI#1-POST
Secondary= 0.00 cfs @ 1.00 hrs, Volume= 0 cf
Routed to Link 1L : POI#1-POST
Routing by Dyn-Stor-Ind method, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs/ 3
Starting Elev= 538.00' Surf.Area= 11,323 sf Storage= 9,199 cf
Peak Elev= 541.49' @ 12.24 hrs Surf.Area= 22,561 sf Storage= 74,191 cf (64,993 cf above start)
Plug-Flow detention time= 123.6 min calculated for 181,193 cf(84% of inflow)
Center-of-Mass det. time= 47.2 min ( 861.2 - 814.0 )
Volume _ Invert _ Avail.Storage Storage Description
#1 536.00' 123,582 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
536.00 1,668 0 0
537.00 2,703 2,186 2,186
538.00 11,323 7,013 9,199
539.00 18,000 14,662 23,860
539.50 18,887 9,222 33,082
540.00 19,790 9,669 42,751
541.00 21,637 20,714 63,465
542.00 23,540 22,589 86,053
543.50 26,498 37,529 123,582
Device Routing Invert Outlet Devices
#1 Secondary 541.50' 24.0' long + 3.0 '/' SideZ x 16.0' breadth EMERGENCY SPILLWAY
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63
#2 Device 5 540.50' 48.0"x 48.0" Horiz. PRINCIPLE SPILLWAY C= 0.700
Limited to weir flow at low heads
#3 Device 5 539.25' 24.0"W x 12.0" H Vert. TEMPORARY POOL WEIR C= 0.600
Limited to weir flow at low heads
#4 Device 5 538.00' 1.7"Vert. PERMANENT POOL ORRIFICE C= 0.600
Limited to weir flow at low heads
#5 Primary 531.62' 24.0" Round OUTLET BARREL
L= 54.0' RCP, end-section conforming to fill, Ke= 0.500
Inlet/Outlet Invert= 531.62' /530.00' S= 0.0300 '/' Cc= 0.900
n= 0.013, Flow Area= 3.14 sf

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 10yr Rainfall=5.32"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 4
Primary OutFlow Max--45.03 cfs @ 12.24 hrs HW=541.48' TW=0.00' (Dynamic Tailwater)
Lam=OUTLET BARREL (Inlet Controls 45.03 cfs @ 14.33 fps)
—2=PRINCIPLE SPILLWAY (Passes < 50.77 cfs potential flow)
—3=TEMPORARY POOL WEIR (Passes < 12.62 cfs potential flow)
—4=PERMANENT POOL ORRIFICE (Passes < 0.14 cfs potential flow)
Secondary OutFlow Max=0.00 cfs @ 1.00 hrs HW=538.00' TW=0.00' (Dynamic Tailwater)
L1=EMERGENCY SPILLWAY ( Controls 0.00 cfs)
Pond SCM: STORMWATER WETLAND
Hydrograph
i
Inflow
66.60 fs 12.10 hrs iOutflow
7/ t: ! I 1 ti
Inflow Area729,122 5f ❑Primary
_ •
= y
70=" .- ;" - cfs @12.Inflovrr 66▪60 1p"hlrs
65= c
Outflow 45 04 cfs "12 24 hits
60-
Primry_45 a ▪04 cfs 2 24 hrs
55=" ;i 1 45 04 cfs @ 12.24 hrs 1
Secondary 0 00 cfs @ 1.00 hrs
;' ;' 145.04 cfs @ 12.24 hrs Peak Elev 541.49'
50 .- ..
= Stora a=T4 191 cf
9
v 4 0
1 l 1 1 i 1 I 1 0 1 1 1 i 1 1 ; 1 : 1 1
a 35=
30_
25
2 ='
15 " i
0.00 cfs @ 1.00 hrs
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST Type 1124-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 5
Summary for Pond SCM: STORMWATER WETLAND
Inflow Area = 726,122 sf, 35.59% Impervious, Inflow Depth > 6.15" for 100yr event
Inflow = 113.06 cfs @ 12.10 hrs, Volume= 372,247 cf
Outflow = 96.87 cfs @ 12.18 hrs, Volume= 346,170 cf, Atten= 14%, Lag= 5.1 min
Primary = 47.09 cfs @ 12.18 hrs, Volume= 301,738 cf
Routed to Link 1L : POI#1-POST
Secondary= 49.78 cfs @ 12.18 hrs, Volume= 44,432 cf
Routed to Link 1L : POI#1-POST
Routing by Dyn-Stor-Ind method, Time Span= 1.00-24.00 hrs, dt= 0.05 hrs/ 3
Starting Elev= 538.00' Surf.Area= 11,323 sf Storage= 9,199 cf
Peak Elev= 542.31' @ 12.18 hrs Surf.Area= 24,150 sf Storage= 93,423 cf (84,225 cf above start)
Plug-Flow detention time= 92.0 min calculated for 336,241 cf (90% of inflow)
Center-of-Mass det. time= 38.8 min ( 837.6 - 798.8 )
Volume Invert Avail.Storage Storage Description
#1 536.00' 123,582 cf Custom Stage Data (Prismatic) Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
536.00 1,668 0 0
537.00 2,703 2,186 2,186
538.00 11,323 7,013 9,199
539.00 18,000 14,662 23,860
539.50 18,887 9,222 33,082
540.00 19,790 9,669 42,751
541.00 21,637 20,714 63,465
542.00 23,540 22,589 86,053
543.50 26,498 37,529 123,582
Device Routing Invert Outlet Devices
#1 Secondary 541.50' 24.0' long + 3.0 '/' SideZ x 16.0' breadth EMERGENCY SPILLWAY
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63
#2 Device 5 540.50' 48.0"x 48.0" Horiz. PRINCIPLE SPILLWAY C= 0.700
Limited to weir flow at low heads
#3 Device 5 539.25' 24.0"W x 12.0" H Vert. TEMPORARY POOL WEIR C= 0.600
Limited to weir flow at low heads
#4 Device 5 538.00' 1.7"Vert. PERMANENT POOL ORRIFICE C= 0.600
Limited to weir flow at low heads
#5 Primary 531.62' 24.0" Round OUTLET BARREL
L= 54.0' RCP, end-section conforming to fill, Ke= 0.500
Inlet/Outlet Invert= 531.62' /530.00' S= 0.0300 '/' Cc= 0.900
n= 0.013, Flow Area= 3.14 sf

STEWARTS GROVE SUBDIVISION
SCM-POST Type II 24-hr 100yr Rainfall=8.09"
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 6
Primary OutFlow Max=47.06 cfs @ 12.18 hrs HW=542.30' TW=0.00' (Dynamic Tailwater)
Lam=OUTLET BARREL (Inlet Controls 47.06 cfs @ 14.98 fps)
—2=PRINCIPLE SPILLWAY (Passes < 120.51 cfs potential flow)
—3=TEMPORARY POOL WEIR (Passes < 15.35 cfs potential flow)
—4=PERMANENT POOL ORRIFICE (Passes < 0.16 cfs potential flow)
Secondary OutFlow Max=48.76 cfs @ 12.18 hrs HW=542.30' TW=0.00' (Dynamic Tailwater)
4-1=EMERGENCY SPILLWAY (Weir Controls 48.76 cfs @ 2.32 fps)
Pond SCM: STORMWATER WETLAND
iiiii Hydrograph
113 ■Inflow
os�r5 12.lo nrs I ■Outflow
i i i '
' Secondary
7- 6��2 r1 ow ; ea= $ ■Primary
120=; ,, ova 1�_3.08...efs..�..-4•2: : ..h.�s....
_
....... .... - .87! ill ! ill �ds @ 12.18 hrs -�'<........_.�/�u;�fk�w=�6�.$7...Gfs..�...12�.A.g...1}f's......
110- '96 Prima -47.i , iip9 cfs @ 12.18 hrs
-
100= ' - .
i Sacondarry-a9.78 ifs . 112.10 hrs
: J .,. Iiiiiiiii
90 I Peak Elev 542 31'
liiiiii
-i
80 i — ,
::
u 70=:'
60= i
'In,no,.awn,o 1u
rs E
- ' i 49fs@12.18 hrs I° : :
50 i +3
i
0V
200 -
10111 �®
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Time (hours)

STEWARTS GROVE SUBDIVISION
SCM-POST
Prepared by Sanders Engineering, PLLC Printed 6/21/2023
HydroCAD® 10.20-2f s/n 12591 ©2022 HydroCAD Software Solutions LLC Page 1
Stage-Area-Storage for Pond SCM: STORMWATER WETLAND
Elevation Surface Storage Elevation Surface Storage
(feet) (sq-ft) (cubic-feet) (feet) (sq-ft) (cubic-feet)
536.00 1,668 0 541.10 21,827 65,638
536.10 1,772 172 541.20 22,018 67,830
536.20 1,875 354 541.30 22,208 70,041
536.30 1,978 547 541.40 22,398 72,272
536.40 2,082 750 541.50 22,589 74,521
536.50 2,186 963 ' 541.60 22,779 76,789
536.60 2,289 1,187 541.70 22,969 79,077
536.70 2,393 1,421 541.80 23,159 81,383
536.80 2,496 1,666 541.90 23,350 83,709
536.90 2,599 1,920 542.00 23,540 86,053
537.00 2,703 2,186 542.10 23,737 88,417
537.10 3,565 2,499 542.20 23,934 90,800
537.20 4,427 2,899 542.30 24,132 93,204
537.30 5,289 3,384 542.40 24,329 95,627
537.40 6,151 3,956 542.50 24,526 98,070
537.50 7,013 4,615 542.60 24,723 100,532
537.60 7,875 5,359 542.70 24,920 103,014
537.70 8,737 6,190 542.80 25,118 105,516
537.80 9,599 7,106 542.90 25,315 108,038
537.90 10,461 8,109 543.00 25,512 110,579
538.00 11,323 9,199 543.10 25,709 113,140
538.10 11,991 10,364 543.20 25,906 115,721
538.20 12,658 11,597 543.30 26,104 118,321
538.30 13,326 12,896 543.40 26,301 120,942
538.40 13,994 14,262 I 543.50 26,498 123,582
538.50 14,662 15,695
538.60 15,329 17,194
538.70 15,997 18,760
538.80 16,665 20,394
538.90 17,332 22,093
539.00 18,000 23,860
539.10 18,177 25,669
539.20 18,355 27,495
539.30 18,532 29,340
539.40 18,710 31,202
539.50 18,887 33,082
539.60 19,068 34,979
539.70 19,248 36,895
539.80 19,429 38,829
539.90 19,609 40,781
540.00 19,790 42,751
540.10 19,975 44,739
540.20 20,159 46,746
540.30 20,344 48,771
540.40 20,529 50,815
540.50 20,714 52,877
540.60 20,898 54,957
540.70 21,083 57,057
540.80 21,268 59,174
540.90 21,452 61,310
541.00 21,637 63,465

SCM DESIGN CALCULATIONS
180 Perry Drive • Southern Pines, NC 28387 • P: [phone] • License# P-2463
www . sandersengineers . com

SANDERS 180 Perry Drive
Southern Pines, NC 28387 FIRM LIC.#:
ENGINEERING 910-725-1020 P-2463
Project NO: 22-008 Calculated/
M.Shane Sanders, PE
Project Name: Stewart's Grove Prepared by:
Project Location: Wingate, NC Checked by: M.Shane Sanders, PE
SCM Description: SCM#1
Simple Method for Runoff Volume Calculations
Drainage area (A) 445,213 sf 10.22 ac
Impervious area 223,804 sf 5.14 ac
Impervious fraction (IA) 0.50
Runoff coefficient (Rv); Rv=0.05 +0.9 x IA 0.50
Design storm depth (RD) 1.00 in
Design volume (DV); DV= 3630 x RD x Rv x A 18,640 cf
Conic Approximation Stage-Storage Volume Calculations
I Incremental Cumulative
Elevation Suface Area (sf) Notes
Volume (cf) _ Volume (cf)
536.00 1,668 0 0 Bottom of basin
537.00 2,703 2,165 2,165
538.00 11,323 6,519 8,684 Permanent Pool
539.00 18,000 14,533 _ 23,217
539.25 18,441 4,555 27,772 WQV
540.00 19,790 14,334 42,106
541.00 21,637 20,707 62,813
541.50 22,581 11,054 73,866 Emer. Spillway
542.00 23,540 11,529 85,396
543.50 26,498 37,507 1.75" Top of Basin
Basin Design Calculation
Permanent pool elevation 538.00 ft
Permanent pool storage volume 8,684 cf
Water quality volume (WQV); permanent pool + DV 27,325 cf
Water quality volume elevation (interpolated) 539.28 ft

SANDERS 180 Perry Drive
Southern Pines,NC 28387 FIRM LIC.#:
ENGINEERINGC 910-725-1020 P-2463
Project NO: 22-008 Calculated/
M.Shane Sanders, PE
Project Name: Stewart's Grove Prepared by:
Project Location: Wingate, NC Checked by: M.Shane Sanders, PE
SCM Description: SCM#1
Constructed Wetland Criteria
Permanent pool elevation 538.00 ft
Temporary pool elevation 539.25 ft
Maximum temporary pool elevation; permanent+ 15" 539.25 -ft
Temporary pool surface area 18,441 sf
Maximum forebay elevation; permanent-40" 534.67 ft
Maximum forebay elevation; pemanent- 2' 536.00 ft
Minimum forebay surface area; 10%of temporary pool 1,844 sf
Maximum forebay surface area; 15%of temporary pool 2,766 sf
Minimum non-forebay elevation; permanent- 18" 536.50 ft
Minimum non-forebay surface area; 5%of temporary pool 922 sf
Maximum non-forebay surface area; 15%of temporary pool 2,766 sf
Minimum shallow water elevation; permanent-9" _ 537.25 —ft
Maximum shallow water elevation; same as permanent 538.00 ft
Minimum shallow water surface area; 35%of temporary pool 6,454 sf
Maximum shallow water surface area; 45%of temporary pool 8,298 sf
Minimum temp. inundation elevation; same as permanent 538.00 ft
Maximum temp. inundation elevation; permenant+ 15" 539.25 _ft
Minimum temp. inundation surface area; 30% of temp. pool 5,532 sf
Maximum temp. inundation surface area; 45%of temp. pool 8,298 sf
Constructed Wetland Design
Permanent pool elevation 538.00 ft
Temporary pool elevation 539.25 ft
Forebay elevation 534.67-536 ft
Non-forebay elevation _ 535.5-536.5 ft
Shallow water elevation 537.25 -538 ft
Shallow land elevation 538-539.25 ft
Temporary pool surface area 18,441 sf
Forebay surface area 1,859 sf 10.08%
Non-forebay surface area 1,637 sf 8.88%
Shallow water surface area 7,827 sf 42.44%
Temp. inundation surface area 7,118 sf 38.60%

SANDERS 180 Perry Drive
Southern Pines, NC 28387 FIRM LICM .#:
E N GIN E E R I N G 910-725-1020 P-246
Project NO: 22-008 Calculated/
Project Name: Stewart's Grove Prepared by: M.Shane Sanders, PE
Project Location: Wingate, NC Checked by: M.Shane Sanders, PE
SCM Description: SCM#1
Constructed Wetland Planting Calculation
Temp. inundation area 7,118 sf
Plants required on Temp. inundation; 50/200 sf 1,780
Percen-
Scientific Name Common Name Quantity
tage
Asclepias Incarnata ,Swamp Milk Weed 356 20%
Lobelia Cardinalis Cardinal Flower _ 356 20%
Eupatoriadelphus Fistulosus ,Joe Pye Weed 356 20%
Hibiscous Coccineus Scarlet Rose Mallow 356 20%
Kosteletzkya Virginica Seashore Mallow 356 20% i
Total 1,780 100%
Shallow water area 7,827 sf
Plants required on shallow land; 50/200 sf 1,957
1
Percen-
Scientific Name Common Name Quantity
tage
Pontederia Cordata Pickerel Weed 326 17%
Saururus Cernuus Lizard's Tail 326 17%
Acorus Subcordatum Sweetflag 326 17%
Juncus Effusus 'Var' Soft Rush 326 17%
Sagittaria Latifolia Duck Potato 326 17%
Scirpus Cyperinus Wool Grass 327 17%
Total 1,957 100%
Total Plants Area 14,945
Total Plants Required _ 3,736
Total Plants Required 3,737

SANDERS 180 Perry Drive
Southern Pines,NC 28387 FIRM LIC.#:
ENGINEERINGJIC 910-725-1020 P-2463
Project NO: 22-008 Calculated/
Project Name: Stewart's Grove Prepared by: M.Shane Sanders, PE
Project Location: Wingate, NC Checked by: M.Shane Sanders, PE
SCM Description: SCM#1
Drawdown Calculations for SCM
Water quality volume (WQV) 19,088 cf
Water quality volume elevation 539.25 ft
Orifice invert elevation 538.00 ft
Orifice equation: Q=CD x A x(2 x g x Ho)o.s
Water quality volume dischage in 2 days (Q); WQV/2/24/3600 0.11 cfs
Water quality volume dischage in 5 days (Q); WQV/5/24/3600 0.04 cfs
Coefficient of discharge (CD) 0.60
Acceleration of gravity (g) 32.20 ft/sec2
Driving head (Ho); (WQV elevation -orifice invert)/3 0.42 ft
Orifice cross-sectional area for 2 days drawdown (A) 0.04 sf
5.12 in2
Orifice diameter for 2 days drawdown 2.55 inches
Orifice cross-sectional area for 5 days drawdown (A) 0.01 sf
2.05 in2
Orifice diameter for 5 days drawdown 1.61 inches
If orifice diameter size is 1.75 inches
Then the drawdown times is 4.26 days

SANDERS 180 Perry Drive
Southern Pines,NC 28387 FIRM LIC.#:
ENGINEERING 910-725-1020 P-2463
Project NO: 22-008 Calculated/
Project Name: Stewart's Grove Prepared by: M.Shane Sanders, PE
Project Location: Wingate, NC Checked by: M.Shane Sanders, PE
SCM Description: SCM#1
Buoyancy Calculations for SCM
Riser interior structure length 4.00 ft
Riser interior structure width 4.00 ft
Top of the riser elevation 540.50 ft
Invert out elevation 531.62 ft
Depth of the riser 8.88 ft
Volume of the riser 142.08 cf
Weight of water 62.40 pcf
Weight of concrete 150.00 pcf
Weight of concrete under water 87.60 pcf
Buoyancy force; Volume of the riser x Weight of water 8,866 _lbf
Factor safety (FS) of 1.2; Buoyancy force x 1.2 10,639 lbf
Riser wall thickness 6 inch
Riser volume; amount of concrete used to make riser 79.92 cf
Riser weight when fully submerged 7,001 lbf
Additional weight needed when fully submerged 3,638 lbf
Additional volume of concrete needed 41.53 cf
Additional depth 2.60 ft
Riser Summary:
Riser interior length 4 ft 0 inches = 48 inches
Riser interior width 4 ft 0 inches = 48 inches
Riser depth 11 ft 6 inches = inches