20110089 Ver 6_SW Control Measures Calculations_20210611

Stormwater Control Measures Calculations
For
UNOX Expansion
Denver, NC
Date: June 8, 2021
CES Project #7544
Prepared By:
srouP
ENGINEERS PLANNERS SURVEYORS SCIENTISTS
CES Group Engineers, LLP
274 N Highway 16, Suite 300
Denver, NC 28037
704.489.1500

UNOX Expansion
SWM Narrative
The proposed project includes construction of an expansion to the existing building with associated
parking lot, drives, sidewalks truck court and sand filter.
The proposed contributing drainage area to the proposed sand filter consists of grass open space,
proposed buildings, sidewalks, parking lots and drives. For purposes of this analysis the drainage area was
divided into impervious and open space areas. The post -development drainage area is 5.6 acres. The
drainage area has HSG B soils which results in a weighted CN value of 85. The post -development time of
concentration was assumed to be 5 minutes.
The proposed sand filter was modeled in HydroCAD. The pond will provide water quality treatment of the
first 1.0" of rainfall over the entire contributing drainage area based on the maximum buildout of the site.
The pond will safely pass the flows from the 2-yr, 10-yr, 25-yr, 50-yr and 100-yr, 24-hour storm events.
The proposed sand filter will not be used as a skimmer basin for the erosion control phases of the
construction. Three separate skimmer basins have been designed to provide sedimentation control during
construction. Once the site is stabilized the sand filter may be installed. The control structure will be a
concrete riser with 4'x4' inside dimensions. The water quality volume will drain completely through the
sand filter media. The water quality elevation will be 780.30. The top of the riser will be set at 780.50 with
a top trash rack extending above this elevation. There will also be a 15' wide emergency spillway on the
south side of the embankment which will be lined with class B riprap on geotextile fabric.

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Citya•?f Charlotte, NC, County of Lincolrj,ate of North Carolina DOT, Esri, HERE, Garmin, INCREMENT P, USGS,
METI/NASA, EPA, USDA

35° 28' 4" N
35° 27' 57" N
3
A
AN
499170
daDoc7 ate ¶ _ O. 3T(8
Soil Map —Lincoln County, North Carolina
� I �
499230 499260 499290
Map Scale: 1:1,520 if printed on A landscape (11" x 8.5") sheet.
0 20 40
80
Meters
120
Feet
0 50 100 200 300
Map projection: Web Mercator Comer coordinates: WGS84 Edge tics: UTM Zone 17N WGS84
499320
•
499350 499380
499410
499410
499440
A
35° 28' 4" N
35° 27' 57' N
USDA Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
4/22/2021
Page 1 of 3

Soil Map —Lincoln County, North Carolina
Area of Interest (AOI)
Soils
0
C
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
• Closed Depression
• Gravel Pit
4 Gravelly Spot
▪ Landfill
Lava Flow
Marsh or swamp
an4 Mine or Quarry
CD Miscellaneous Water
• Perennial Water
▪ Rock Outcrop
▪ Saline Spot
4 •
#• Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
oa Sodic Spot
g Spoil Area
0 Stony Spot
Very Stony Spot
Wet Spot
▪ Other
Special Line Features
Water Features
Streams and Canals Please rely on the bar scale on each map sheet for map
measurements.
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Transportation
Rails
ighe Interstate Highways
O .10 US Routes
Major Roads
Local Roads
Background
. Aerial Photography
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Lincoln County, North Carolina
Survey Area Data: Version 24, Jun 4, 2020
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Oct 28, 2018—Oct
30, 2018
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
USDA Natural Resources
rilra Conservation Service
Web Soil Survey
National Cooperative Soil Survey
4/22/2021
Page 2 of 3

Soil Map —Lincoln County, North Carolina
Map Unit Legend
Map Unit Symbol
Map Unit Name
Acres in AOI
Percent of AOI
MdB2
Madison sandy clay loam, 2 to
8 percent slopes, moderately
eroded
5.1
54.7%
MdC2
Madison sandy clay loam, 8 to
15 percent slopes,
moderately eroded
4.2
45.3%
Totals for Area of Interest
9.4
100.0%
USDA Natural Resources Web Soil Survey 4/22/2021
Conservation Service National Cooperative Soil Survey Page 3 of 3

Map Unit Description: Madison sandy clay loam, 8 to 15 percent slopes, moderately eroded ---
Lincoln County, North Carolina
Lincoln County, North Carolina
MdC2—Madison sandy clay loam, 8 to 15 percent slopes,
moderately eroded
Map Unit Setting
National map unit symbol: 2mw6j
Elevation: 200 to 1,400 feet
Mean annual precipitation: 37 to 60 inches
Mean annual air temperature: 59 to 66 degrees F
Frost -free period: 200 to 240 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Madison, moderately eroded, and similar soils: 85 percent
Estimates are based on observations, descriptions, and transects of
the mapunit.
Description of Madison, Moderately Eroded
Setting
Landform: Hillslopes on ridges
Landform position (two-dimensional): Backslope
Landform position (three-dimensional): Side slope
Down -slope shape: Linear
Across -slope shape: Convex
Parent material: Residuum weathered from mica schist and/or other
micaceous metamorphic rock
Typical profile
Ap - 0 to 6 inches: sandy clay loam
Bt - 6 to 26 inches: clay
BC - 26 to 37 inches: clay loam
C - 37 to 80 inches: loam
Properties and qualities
Slope: 8 to 15 percent
Depth to restrictive feature: More than 80 inches
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water
(Ksat): Moderately high to high (0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Moderate (about 8.3 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
USDA Natural Resources Web Soil Survey 4/22/2021
Conservation Service National Cooperative Soil Survey Page 1 of 2

Map Unit Description: Madison sandy clay loam, 8 to 15 percent slopes, moderately eroded ---
Lincoln County, North Carolina
Hydric soil rating: No
Data Source Information
Soil Survey Area: Lincoln County, North Carolina
Survey Area Data: Version 24, Jun 4, 2020
USDA Natural Resources Web Soil Survey 4/22/2021
Conservation Service National Cooperative Soil Survey Page 2 of 2

Map Unit Description: Madison sandy clay loam, 2 to 8 percent slopes, moderately eroded ---
Lincoln County, North Carolina
Lincoln County, North Carolina
MdB2—Madison sandy clay loam, 2 to 8 percent slopes,
moderately eroded
Map Unit Setting
National map unit symbol: 2mw6h
Elevation: 200 to 1,400 feet
Mean annual precipitation: 37 to 60 inches
Mean annual air temperature: 59 to 66 degrees F
Frost -free period: 200 to 240 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Madison, moderately eroded, and similar soils: 85 percent
Estimates are based on observations, descriptions, and transects of
the mapunit.
Description of Madison, Moderately Eroded
Setting
Landform: Interfluves
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from mica schist and/or other
micaceous metamorphic rock
Typical profile
Ap - 0 to 6 inches: sandy clay loam
Bt - 6 to 26 inches: clay
BC - 26 to 34 inches: sandy clay loam
C - 34 to 80 inches: loam
Properties and qualities
Slope: 2 to 8 percent
Depth to restrictive feature: More than 80 inches
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water
(Ksat): Moderately high to high (0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Moderate (about 8.3 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: B
USDA Natural Resources Web Soil Survey 4/22/2021
Conservation Service National Cooperative Soil Survey Page 1 of 2

Map Unit Description: Madison sandy clay loam, 2 to 8 percent slopes, moderately eroded ---
Lincoln County, North Carolina
Hydric soil rating: No
Data Source Information
Soil Survey Area: Lincoln County, North Carolina
Survey Area Data: Version 24, Jun 4, 2020
USDA Natural Resources Web Soil Survey 4/22/2021
Conservation Service National Cooperative Soil Survey Page 2 of 2

Sand Filter Design
DATE: 4/29/2021
PROJECT: UNOX Expansion
PROJECT #: 7544.0121DD
DESIGNER: SMC
NCDEQ Stormwater Design Manual
Chapter 6 - Sand Filter (November 7, 2018)
1 SITE DATA
Pre-Dev Post-Dev Target Sand Filter Effectiveness
Area to Sand Filter (sf) 244096
Area to Sand Filter (ac) 0.00 5.60 Detention Time (days)* 2
Impervious (sf) 160644 Media Depth 1.5 ft
Impervious (ac) 3.69 Removal Rate 85% TSS
Pervious (ac) 0.00 1.92
Impervious #DIV/0! 66% *measured from the midpoint of the design storm
2 WATER QUALITY CALCULATIONS
Runoff Coefficient, Rv
WQv (ac-ft)
WQv (in)
WQv (cf)
75% WQv (!cf)
hmaz filter(ft)
ha„ g (ft)
Surface Area of Sand Filter (ft)
0.64
0.300
0.64
13,065
9,799
4.00
2.00
2,450
WQv =
R„=0.05+0.009*/
1.0*R„*A
12
*allowed for sand filters per MDC 3
3 HYDROLOGIC PARAMETERS
Pre-Dev Post-Dev
Area (sf) 0 244,096
Area (ac) 0.00 5.60
CN 0 85
CN,„ (modified, P=1 in) 96 96
Travel Time Tt (min) 5
CN =
1000
[10 + 5P + 10WQ„ — 10(WQ„2 + 1.25WQ„P)° 5]
CURVE NUMBER CALCULATION
Pre -Development
Area HSG CN CN*Area
Sum
CN Weighted
Post -Development
Area HSG CN CN*Area
Impervious 3.69 B 98 361.41
Open Space 1.92 B 61 116.86
0.00
478.28 Sum
85 CN Weighted
4 WATER QUALITY PEAK FLOW
WQp (cfs) 58.66 *From HydroCAD
5 CHANNEL PROTECTION VOLUME
S (in)
P (in, 1-yr, 24-hr))
Qd (in)
CPv (ac-ft)
6 RELEASE RATES
Post-Dev 1000
1.72 S —
CN-10
1.272.58 Qd _ (2.58 — 0.2S)2
0.59 d(P
* A .8S)
CP — Qd
12
Drawdown Time (hr)
Water Quality 48
Channel Protection
Post-Dev
Ms, Release (cfs) 0.076
CPv Release (cfs) #DIV/0!
CP, Release Rate =
(DrawdownTime * 3,600)
WQ, Release Rate =
(DrawdownTime * 3,600)
(43,560 * CP„)
(43,560 * WQ„)

Sand Filter Design
7 SEDIMENTATION AND FILTRATION CHAMBERS
SEDIMENTATION
As (ft2) 863.8
FILTRATION
Filter Bed Depth, df (ft)
Permeability, k (ft/day)
Avg height of water, hi (ft)
Filter Drain Time, tf (days)
Filter Surface Area, AF (ft2)
Length -to -Width Ratio
Length (ft)
Width (ft)
1.5
3.5
2.000
2.000
600
2
34.6
17.3
240*Rv*DA *Rd
WQ„*df
Af =
k*(/ti+df)*tf
8 STAGE -STORAGE
Stage (ft) Area (ft2)
779.00
780.00
781.00
782.00
783.00
783.50
1,975
2,596
3,282
4,034
4,851
5,285
Area (ac) Avg Area (ac)
0.0453 0.0000
0.0596 0.0525
0.0753 0.0675
0.0926 0.0840
0.1114 0.1020
0.1213 0.1163
Volume (ac-ft)
Increm. Cumulative
0.0000 0.0000
0.0525 0.0525
0.0675 0.1199
0.0840 0.2039
0.1020 0.3059
0.0582 0.3641
9 STAGE -DISCHARGE
Top of Filter Media
Stage
779.00
780.00
781.00
782.00
783.50
Height
0
1
2
3
4.5
779
Discharge (cfs)
0.000
0.041
0.057
0.073
0.097
10 WATER QUALITY AND CHANNEL PROTECTION ELEVATIONS
WATER QUALITY ELEVATION
Stage Storage (ac-ft)
_782 0.2039
- 782.21- 7 0.2250
0.3059
CHANNEL PROTECTION ELEVATION
Stage Storage (ac-ft)
#N/A
#N/A 0.5910
-----' #N/A
11 DRAWDOWN AND UNDERDRAIN DESIGN
Minimum Drawdown Discharge
WQ„ (ft3) 9,799
Drawdown (cfs) 0.076
Compute Perforation Capacity
No. of pipes
Length of each pipe (ft)
Number of cleanouts per pipe
Rows per foot
Holes per Row
Number of perforations
Percent clogged
Unclogged Perforations
Storage Depth (ft)
Perforation Capacity (cfs)
Total Capacity (cfs)
3
24
2
4
4
1056
50%
528
2
0.0052
2.7576
Compute Underdrain Capacity
Underdrain Slope (ft/ft) 0.01
Underdrain Size (in) 6
Underdrain A (ft2) 0.196
Underdrain P (ft) 1.571
Underdrain Capacity (cfs) 0.56
Unclogged Capacity (cfs) 0.28
`Needs to be greater than 1' depth
discharge and min. drawdown capacity

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1 inch = 40 ft.
LEGEND
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PROPOSED
850
CONTOUR WITH ELEVATION
CONCRETE CURB & GUTTER
PROPERTY LINE
CATCH BASIN / CURB INLET
STORM DRAIN AND ENDWALL
BASIN DRAINAGE AREA BOUNDARY
INLET DRAINAGE AREA BOUNDARY
ErouP
ENGINEERS
PLANNERS
SURVEYORS
SCIENTISTS
CES Group Engineers, LLP
NC FIRM LICENSE #F-1240
274 N. Hwy. 16, SUITE 300
DENVER, NC 28037
T 704. 489.1500
www.ces-group.net
SEAL: `I
SUBMITTALS
DATE:
PURPOSE:
OWNER / DEVELOPER
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PROJECT DESCRIPTION:
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UNOX EXPANS
987 AIRLIE PARKWAY, DENVER, NC
PROJECT NO:
7544 - 0121
DRAWING REVISIONS
NO:
REVISION DESC.
DATE:
DRAWN BY: MK
REVISED BY:
CHECKED BY: SC
ISSUED BY: SC
DRAWING TITLE:
DRAINAGE AREA
MAP
SAND FILTER
DRAWING NUMBER:
1
Copyright 2021 CES Group Engineers, LLP

UNOX Expansion
Project Number:
7544.0121
Description
Original Date:
4/29/21
DB:
SMC
Revision Date:
1I0/00
PM:
SMC
Location
I Inlet I
I Areas I
Storm Runoff
1
1
Pipe Sizing Calculations
1
1
I
1 Pipe Input/Cover Calculations
1
Percent 1
Percent 1 Composite 1
1 Inlet
1 Combined ;
;
I Pipe I
I
1
1 Pipe 1
1 1
1
ripe
Time 1
1 1 1 1
I
From I To
1 1 1
1
1 I 1 Pipe I I
Dtheo I 1
Vfull
1 Capacity I
1
I
I
1 I I 1
I
Structure !Structure
(acres)
Pervious l Impervious; Runoff 1
I (in/hr)
1 Discharge Q
1 Discharge 1 Material n ;Slope (%)1 Length I
(in) I Size (in) I
(fps)
I Q-full 1 Q/Q-full
1d/dm ratio')
vN-full
1 Actual
(min)- 1 Actual
1 1 Structure' Depth Of '
1
Pipe
I
(%) (%) Coeff. Cc
I I I
(cfs)
I
Qpipe (cfs)1 (ft)
I I I I
I I
I (cts) I
I I
Vpipe
I
, (fps)
Full Pipe Time
1
Cond. , (min)
Pipe Pipe Rim Cover (Based
1 1 I I
Inv. Out, Inv. In , Elevation , on Rim) ,
Pipe
1
Material ,
Material
Class
CB-6 I CB-5
I 0.52 1 20% I
80% I
0.82
I
7.10
I 3.06
I 3.06 I
0.013 I
2.00%
188.61 I
9.9 I
15 I
7.5
I 9.15 I
0.33
I 0.40 I
0.87
I 6.49 I 0.20 I
0.23
1796.001 794.231 800.60 I 3.10 I
RCP I
Class III
1
CB-5 1 DI-4
1 I 1
1 0.18 1 20% 1
1
80% 1
0.82
1
1
7.10
1
1 1.05
1 I
1 4.11
I
0.013
2.00%
I I
51.88
1
11.1
I
15 1
7.5
I I
1 9.17 1
0.45
I I
1 0.45 1
0.94
I I I
1 7.02 1 0.31 1
0.35
I I I I I
1 794.13 1 793.091 800.04 1 4.41
I
RCP 1
Class III
DI-4 1 MH-3
1 0.04 1 40% 1
60% 1
0.69
1
7.10
1 0.21
1 4.32 I
0.013 I
2.00%
150.97 111.3
I
15 1
7.5
1 9.16 1
0.47
1 0.45 1
0.94
1 7.02 1 0.43 1
0.47
1 792.991 791.971 801.00 I 6.51 I
RCP 1
Class III
MH-3 I DI-2
I 0.44 1 0% I
100% I
0.95
I
7.10
I 2.94
I 7.26 I
0.013 I
5.00%
143.60I
11.6 I
15 I 11.8 I 14.48 I
0.50
I 0.50 I
0.99
111.68 I 0.49 I
0.53
1791.871789.691 802.22 I 8.85 I
HDPE I
-
1
DI-2 1 FES-1
1 I 1
1 0.03 1 100% 1
1
0% 1
0.30
1
1
7.10
1
1 0.06
1 I
1 7.32 1
I
0.013 1
2.02%
I I
1 21.281
I
13.8 1
tF 1
15 1 7.5 1 9.21 1
0.79
1 1
1 0.65 1
1.12
1 1 1
1 6.87 1 0.54 1
0.59
1 1 1 I I
1 786.43 1 786.001 791.13 1 3.20 1
1
HDPE 1
-
1
1 1 1
1
1
1
1 I
I
I I
I
1
1 1
1 1
1 1 1
1 1 1 I I
I
DCB-12
CB-11
1 2.71 1 30% I
70% I
0.76
I
7.10
I 14.51
I 14.51 I
0.013 I
2.00%
1116.091
17.8 I
24 I
10.2
I 32.07 I
0.45
I 0.45 I
0.94
I 9.59 I 0.39 I
0.20
1792.20 1 789.881 796.21 I 1.70 I
RCP I
Class IV
CB-11
DI-10
1
0.15 25%
I I 1
1
75% 1
0.79
1
1
7.10
1
1 0.84
1 1
15.34
1 1
1
0.013 1
1.99%
1 1
78.73
1 1
1
18.2 1
1
24 1
10.2
1 1
32.03
1 1
0.48
1 1
0.45
1 1
0.94
1 1 1
9.58 0.44
1 1 1
0.14
1 1 1 1 1
789.78788.21797.27 5.18
1 1 1 1 1
1
RCP 1
Class III
01-10
DI-9
1 0.04 1 40% 1
60% 1
0.69
1
7.10
1 0.17
1 15.52 I
0.013 I
2.00%
176.15 1
18.3 I
24 1
10.2
1 32.05 1
0.48
1 0.45 1
0.94
1 9.59 1 0.55 1
0.13
1 788.11 1 786.591 798.93 I 8.51 I
RCP 1
Class III
DI-9
DI-8
1 0.47 1 35% I
65% I
0.72
I
7.10
I 2.43
I 17.94 I
0.013 I
4.99%
135.261
16.3 I
24 I
16.1
I 50.68 I
0.35
I 0.40 I
0.87
114.03 I 0.53 I
0.04
1786.49 1784.731 800.99 I 12.19 I
HDPE I
-
DI-8
FES-7
0.16 100% 1
I I I
0% 1
1
0.30
1
1
7.10
1 0.33
1
1 18.28 1
1 1
0.013 1
1
1.99%
1 44.621
1 1
19.4 1
1
24 1
I
10.2
1 32.04 1
I I
0.57
1 0.50 1
I I
0.99
1 10.10 1 0.61 1
I I I
0.07
1779.891779.001 792.04 1 9.84 1
I I I 1 1
HDPE 1
I
-
I I 1
1
1
1
1 I
I
I I
I
1
1 1
1 1
1 1 1
1 1 1 I I
1
Hold receiving pipe invert
Pipe invert higher than receiving
Drop in inverts

Rip -Rap Apron Summary Table
Outlet
I I
I Discharge I Do (in)
I (cfs) I
1 1
Minimum TW Condition
I
d50 (ft) I
1
I W1=Do + La I W2=3*Do W21
La (ft) I Wi (ft) I (ft) I
*T(ft)
I H=(2/3)*Do
I H (ft)
FES-1
I
7.3
I
15
I 0.5 I
10 1 11.25 1 3.75 1
1.125
I
0.83
FES-7
I
18.3
I
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dmax=1.5*d50
*T=1.5*dmax (Min. *T=10") Apron Thickness = *T
Min. La=10 ft
H=Depth of apron

d50 Riprap Size (ft)
Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<0.5 diameter)
Outlet
pipe
diameter (Do)
La —61
ilwater < 0.5Do
.0o+La
cl r'�t �rc:,
0,64.,v 50
0
20 50 100 200 500 1000
Discharge (ft3lsec)
Curves may not be extrapolated.
Figure 8.063 Design of outlet protection protection from a round pipe flowing full. minimum tailwater condition (T„, < 0.5 diameter)
Rev. 12 A3
8.06.3

d50 Riprap Size (ft)
Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<0.5 diameter)
Outlet
pipe
diameter (Do)
La —61
ilwater < 0.5Do
. po+La
�r cl �tc�:,
er9
20 50 100
Discharge (ft3lsec)
200 500 10D0
Curves may not be extrapolated.
Figure 8.063 Design of outlet protection protection from a round pipe flowing full. minimum tailwater condition (T„, < 0.5 diameter)
Rev. 12 A3
8.06.3

CES Group Engineers, LLP
274 N. Highway 16
Denver, NC 28037
Sugar Creek Charter School
Project Number:
7498
Original Date:
12/30/20
DB:
SMC
Revision Date:
2/16/2021
PM:
SMC
Standard Data
Standard Footing Assumptions
Buoyant Weight of Concrete
87.6IIbs/ft^3
1. Footing base can be filled with concrete
2. Footing depth to be a minimum of 8 inches in depth.
Weight of Water
I
62.4llbs/ft^3
Safety Factor (S.F.)
1
1.501
Outlet Structure - Dry Pond
Structure Dimensions
Object Weights
Height of structure, h =
1 4
1ft.
Outlet Structure Weight, W(s) =1
385411bs
Structure wall thickness, t =1
6
lin.
Displaced Water Weight, W(w) =1
5990.41Ibs
Outlet box inside dimension, w =1
5
Ift.
Req'd Base Weight, W(b) =1
513111bs
Footing Size
Required Footing Volume, V(f) _;
59Icf Standard Footing Length, L =1
7.00Ift.
Provided Footing Volume, V(f) =1
741cf Standard Footing Width, W =1
7.00Ift.
1 Footing Checkl
okay! Minimum Footing Depth, D =I
1.50Ift.
Footing Size to be used:
Length = 7.00
!Width = 7.00
IDepth = 1.50
ft.
ft.
ft.
Outlet Structure - Dry Pond
Equations used:
Outlet Structure Weight, W(s) = 4(w + t) x t x h x W(bc)
Displaced Water Weight, W(w) = 4 x (w + 2t) x W(w) x h
Required Base Weight, W(b) = (W(w) x S.F.) - W(s)
Required Footing Volume, V(f) = W(b) / W(bc)
where, w = outlet box inside dimension, ft.
t = structure wall thickness, ft.
h = height of structure, ft.
W(bc)= buoyant weight of concrete, Ibs/ft^3
W(w)= weight of water, Ibs/ft^3
S.F.= safety factor
I

SOUTHERN ENGINEERING
Consulting • Engineering • Construction Testing • Special Inspections
July 20, 2017
Mr. David Lutz, P.E.
CES Group Engineers
274 N Highway 16
Suite 300
Denver, NC 28037
Re: Airlie Park Spec Building
Seasonal High Ground Water Determination
Denver, North Carolina
SE&T Project No.: 17-108
Dear Mr. Lutz,
SOUTHERN ENGINEERING is pleased to provide geotechnical engineering services for the Airlie Park Spec Building in
Denver, NC. Our services included a subsurface exploration to observe the site soils for indicators of seasonal high
ground water, ground water and other impermeable strata. Our service was provided in accordance with the scope of
service defined in our proposal number 17-10222. Authorization to provide this service was in the form of a signed
proposal agreement.
A rubber -tracked hydraulic excavator (Takeuchi TB 250) was mobilized to the site on June 14, 2017. Three observation
pits were located and excavated at this site in the vicinity of the planned ponds. The test pits were located using a
handheld Garmin GPS device (reported accuracy ±30 feet). The approximate locations of the test pits are indicated on
the Test Pit Location Plan included with this letter report.
The observation pits were excavated to depths ranging from approximately 56 to 108 inches below the existing ground
surface. The encountered soils were classified using the USDA Classification System (Textural) and Unified Soil
Classification System (USCS) for soil. The test pits were observed and logged by an experienced registered professional
engineer licensed in the State of North Carolina. Our interpretation of the soil horizon, depth, color (Munsell) and
textural classification are presented on the attached test pit logs. Additionally, groundwater and seasonal high ground
water table (SHWT) indicators were noted, if encountered.
The results of the subsurface exploration did not reveal the presence of ground water, seasonal high ground water table
indications nor other impermeable strata within the observation pits. The site appears suitable for the planned usage as
stormwater management ponds.
Respectfully submitted,
SOUTHERN ENGINEEI NKe ATESTING, P.C.
NC Lic/ f e No. C-4167; S i iic 4 rity 5297
ichard E. Fin ien,°,.�'r.
President o°
Enclosures: Test tj.
AL oe�e
492
-'G
c tiq'Qand Test Pit Logs
/INJgg1i\\
SOUTHERN ENGINEERING AND TESTING, P.C. 6120 Q Brookshire Boulevard, Charlotte, NC 28216
Office [phone] Main [phone] Facsimile [phone]

Important Intormation about Thi
Geotechnical-Engineering Report
Subsurface problems are a principal cause of construction delays, cost overruns, claims, and disputes.
While you cannot eliminate all such risks, you can manage them. The following information is provided to help.
The Geoprofessional Business Association (GBA)
has prepared this advisory to help you — assumedly
a client representative — interpret and apply this
geotechnical-engineering report as effectively
as possible. In that way, clients can benefit from
a lowered exposure to the subsurface problems
that, for decades, have been a principal cause of
construction delays, cost overruns, claims, and
disputes. If you have questions or want more
information about any of the issues discussed below,
contact your GBA-member geotechnical engineer.
Active involvement in the Geoprofessional Business
Association exposes geotechnical engineers to a
wide array of risk -confrontation techniques that can
be of genuine benefit for everyone involved with a
construction project.
Geotechnical-Engineering Services Are Performed for
Specific Purposes, Persons, and Projects
Geotechnical engineers structure their services to meet the specific
needs of their clients. A geotechnical-engineering study conducted
for a given civil engineer will not likely meet the needs of a civil -
works constructor or even a different civil engineer. Because each
geotechnical-engineering study is unique, each geotechnical-
engineering report is unique, prepared solely for the client. Those who
rely on a geotechnical-engineering report prepared for a different client
can be seriously misled. No one except authorized client representatives
should rely on this geotechnical-engineering report without first
conferring with the geotechnical engineer who prepared it. And no one
- not even you - should apply this report for any purpose or project except
the one originally contemplated.
Read this Report in Full
Costly problems have occurred because those relying on a geotechnical-
engineering report did not read it in its entirety. Do not rely on an
executive summary. Do not read selected elements only. Read this report
in full.
underground utilities.
You Need to Inform Your Geotechnical Engineer
about Change
Your geotechnical engineer considered unique, project -specific factors
when designing the study behind this report and developing the
confirmation -dependent recommendations the report conveys. A few
typical factors include:
• the client's goals, objectives, budget, schedule, and
risk -management preferences;
• the general nature of the structure involved, its size,
configuration, and performance criteria;
• the structure's location and orientation on the site; and
• other planned or existing site improvements, such as
retaining walls, access roads, parking lots, and
utilities.
Typical changes that could erode the reliability of this report include
those that affect:
• the site's size or shape;
• the function of the proposed structure, as when it's
changed from a parking garage to an office building, or
from a light -industrial plant to a refrigerated warehouse;
• the elevation, configuration, location, orientation, or
weight of the proposed structure;
• the composition of the design team; or
• project ownership.
As a general rule, always inform your geotechnical engineer of project
changes - even minor ones - and request an assessment of their
impact. The geotechnical engineer who prepared this report cannot accept
responsibility or liability for problems that arise because the geotechnical
engineer was not informed about developments the engineer otherwise
would have considered.
This Report May Not Be Reliable
Do not rely on this report if your geotechnical engineer prepared it:
• for a different client;
• for a different project;
• for a different site (that may or may not include all or a
portion of the original site); or
• before important events occurred at the site or adjacent
to it; e.g., man-made events like construction or
environmental remediation, or natural events like floods,
droughts, earthquakes, or groundwater fluctuations.
Note, too, that it could be unwise to rely on a geotechnical-engineering
report whose reliability may have been affected by the passage of time,
because of factors like changed subsurface conditions; new or modified
codes, standards, or regulations; or new techniques or tools. If your
geotechnical engineer has not indicated an `apply -by" date on the report,
ask what it should be, and, in general, if you are the least bit uncertain
about the continued reliability of this report, contact your geotechnical
engineer before applying it. A minor amount of additional testing or
analysis - if any is required at all - could prevent major problems.
Most of the "Findings" Related in This Report Are
Professional Opinions
Before construction begins, geotechnical engineers explore a site's
subsurface through various sampling and testing procedures.
Geotechnical engineers can observe actual subsurface conditions only at
those specific locations where sampling and testing were performed. The
data derived from that sampling and testing were reviewed by your
geotechnical engineer, who then applied professional judgment to
form opinions about subsurface conditions throughout the site. Actual
sitewide-subsurface conditions may differ - maybe significantly - from
those indicated in this report. Confront that risk by retaining your
geotechnical engineer to serve on the design team from project start to
project finish, so the individual can provide informed guidance quickly,
whenever needed.
_J

This Report's Recommendations Are
Confirmation -Dependent
The recommendations included in this report - including any options
or alternatives - are confirmation -dependent. In other words, they are
not final, because the geotechnical engineer who developed them relied
heavily on judgment and opinion to do so. Your geotechnical engineer
can finalize the recommendations only after observing actual subsurface
conditions revealed during construction. If through observation your
geotechnical engineer confirms that the conditions assumed to exist
actually do exist, the recommendations can be relied upon, assuming
no other changes have occurred. The geotechnical engineer who prepared
this report cannot assume responsibility or liability for confirmation -
dependent recommendations if you fail to retain that engineer to perform
construction observation.
This Report Could Be Misinterpreted
Other design professionals' misinterpretation of geotechnical-
engineering reports has resulted in costly problems. Confront that risk
by having your geotechnical engineer serve as a full-time member of the
design team, to:
• confer with other design -team members,
• help develop specifications,
• review pertinent elements of other design professionals'
plans and specifications, and
• be on hand quickly whenever geotechnical-engineering
guidance is needed.
You should also confront the risk of constructors misinterpreting this
report. Do so by retaining your geotechnical engineer to participate in
prebid and preconstruction conferences and to perform construction
observation.
Give Constructors a Complete Report and Guidance
Some owners and design professionals mistakenly believe they can shift
unanticipated -subsurface -conditions liability to constructors by limiting
the information they provide for bid preparation. To help prevent
the costly, contentious problems this practice has caused, include the
complete geotechnical-engineering report, along with any attachments
or appendices, with your contract documents, but be certain to note
conspicuously that you've included the material for informational
purposes only. To avoid misunderstanding, you may also want to note
that "informational purposes" means constructors have no right to rely
on the interpretations, opinions, conclusions, or recommendations in
the report, but they may rely on the factual data relative to the specific
times, locations, and depths/elevations referenced. Be certain that
constructors know they may learn about specific project requirements,
including options selected from the report, only from the design
drawings and specifications. Remind constructors that they may
perform their own studies if they want to, and be sure to allow enough
time to permit them to do so. Only then might you be in a position
to give constructors the information available to you, while requiring
them to at least share some of the financial responsibilities stemming
from unanticipated conditions. Conducting prebid and preconstruction
conferences can also be valuable in this respect.
Read Responsibility Provisions Closely
Some client representatives, design professionals, and constructors do
not realize that geotechnical engineering is far less exact than other
engineering disciplines. That lack of understanding has nurtured
unrealistic expectations that have resulted in disappointments, delays,
cost overruns, claims, and disputes. To confront that risk, geotechnical
engineers commonly include explanatory provisions in their reports.
Sometimes labeled "limitations,' many of these provisions indicate
where geotechnical engineers' responsibilities begin and end, to help
others recognize their own responsibilities and risks. Read these
provisions closely. Ask questions. Your geotechnical engineer should
respond fully and frankly.
Geoenvironmental Concerns Are Not Covered
The personnel, equipment, and techniques used to perform an
environmental study - e.g., a "phase -one" or "phase -two" environmental
site assessment - differ significantly from those used to perform
a geotechnical-engineering study. For that reason, a geotechnical-
engineering report does not usually relate any environmental findings,
conclusions, or recommendations; e.g., about the likelihood of
encountering underground storage tanks or regulated contaminants.
Unanticipated subsurface environmental problems have led to project
failures. If you have not yet obtained your own environmental
information, ask your geotechnical consultant for risk -management
guidance. As a general rule, do not rely on an environmental report
prepared for a different client, site, or project, or that is more than six
months old.
Obtain Professional Assistance to Deal with Moisture
Infiltration and Mold
While your geotechnical engineer may have addressed groundwater,
water infiltration, or similar issues in this report, none of the engineer's
services were designed, conducted, or intended to prevent uncontrolled
migration of moisture - including water vapor - from the soil through
building slabs and walls and into the building interior, where it can
cause mold growth and material -performance deficiencies. Accordingly,
proper implementation of the geotechnical engineer's recommendations
will not of itself be sufficient to prevent moisture infiltration. Confront
the risk of moisture infiltration by including building -envelope or mold
specialists on the design team. Geotechnical engineers are not building -
envelope or mold specialists.
GENAla GEOPROFESSIONAL
BUSINESS
- ASSOCIATION
Telephone: [phone]
e-mail: [e-mail] wwwgeoprofessional.org
Copyright 2016 by Geoprofessional Business Association (GBA). Duplication, reproduction, or copying of this document, in whole or in part, by any means whatsoever, is strictly
prohibited, except with GBAs specific written permission. Excerpting, quoting, or otherwise extracting wording from this document is permitted only with the express written permission
of GBA, and only for purposes of scholarly research or book review. Only members of GBA may use this document or its wording as a complement to or as an element of a report of any
kind. Any other firm, individual, or other entity that so uses this document without being a GBA member could be committing negligent

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SOUTHERN ENGIAEE'RING
Cme-lri• Ea 31rrrin•Cme,rorow Tr-cin• 9proa7I.prroole
Southern Engineering and Testing, P.C.
6120 Brookshire Blvd, Suite Q
Charlotte, NC 28016
Telephone: [phone]
Fax: [phone]
BORING NUMBER 108-1
PAGE 1 OF 1
CLIENT CES Group Engineers PROJECT NAME Airlie Park Spec Building SHWT Study
PROJECT NUMBER 17-108 PROJECT LOCATION Denver, NC
DATE STARTED 6/14/17 COMPLETED 6/14/17
GROUND ELEVATION 767 ft HOLE SIZE inches
DRILLING CONTRACTOR Takeuchi TB250 w/thumb & 24-inch bucket GROUND WATER LEVELS:
AT TIME OF DRILLING ---
LOGGED BY RF CHECKED BY RF AT END OF DRILLING AFTER DRILLING ---
DRILLING METHOD Observation Pit
NOTES Surface Elevation is approximate.
U
vi
U_
20
0 O
Q
MATERIAL DESCRIPTION
2.5
OL
(OL) 0 to 6-inches, Brown (7.5YR4/4) loamy sand, Horizon A
0.5 766.5
SM
(SM) 6 to 24-inches, Dark brown (7.5YR3/4) sandy loam, Horizon B
2.0 765.0
S P-
SM
(SP-SM) 24 to 56-inches, Light brown (7.5YR6/4) loamy sand, Horizon C; Cr near 56-inches (dense)
4.7 762.3
Refusal at 4.7 feet.
Bottom of borehole at 4.7 feet.

Southern Engineering and Testing, P.C. BORING NUMBER 108-2
6120 Brookshire Blvd, Suite Q PAGE 1 OF 1
SOUTHERN ENGIAFEERING tme lmn•Ea 31rrrnn•Cwe7ncowrr-�•9proa7Imprroo� Charlotte, NC 28016
Telephone: [phone]
Fax: [phone]
CLIENT CES Group Engineers PROJECT NAME Airlie Park Spec Building SHWT Study
PROJECT NUMBER 17-108 PROJECT LOCATION Denver, NC
DATE STARTED 6/14/17 COMPLETED 6/14/17 GROUND ELEVATION 779 ft HOLE SIZE inches
DRILLING CONTRACTOR Takeuchi TB250 w/thumb & 24-inch bucket GROUND WATER LEVELS:
DRILLING METHOD Observation Pit AT TIME OF DRILLING ---
LOGGED BY RF CHECKED BY RF AT END OF DRILLING -
NOTES Surface Elevation is approximate. AFTER DRILLING ---
p DEPTH
(ft)
SAMPLE TYPE
NUMBER
vi
ci
ui
GRAPHIC
LOG
MATERIAL DESCRIPTION
2.5
OL
''L '`-`
r;..S
1,. ,� /;.
•0'! •,A
(OL) 0 to 13-inches, Strong brown (7.5YR4/6) silt loam, Horizon Ap
1.1 777.9
SM
(SM) 13 to 35-inches, Strong brown (7.5YR5/6) silt loam, Horizon B
2.9 776.1
- -
5.0
SP-'
SM
(SP-SM) 35 to 75-inches, Brown (7.5YR5/4) loamy sand, Horizon B/C
6.3 772.8
7.5
SP-
SM
(SP-SM) 75 to 108-inches, Brown (7.5YR4/4) sandy clay loam, Horizon C
9.0 770.0
Bottom of borehole at 9.0 feet.

Southern Engineering and Testing, P.C. BORING NUMBER 108-3
6120 Brookshire Blvd, Suite Q PAGE 1 OF 1
SOUTHERN ENGINEERING Charlotte, NC 28016 .p3m« . C•meenclical rase. Special lespeclims
Telephone: [phone]
Fax: [phone]
CLIENT CES Group Engineers PROJECT NAME Airlie Park Spec Building SHWT Study
PROJECT NUMBER 17-108 PROJECT LOCATION Denver, NC
DATE STARTED 6/14/17 COMPLETED 6/14/17 GROUND ELEVATION 777 ft HOLE SIZE inches
DRILLING CONTRACTOR Takeuchi TB250 w/thumb & 24-inch bucket GROUND WATER LEVELS:
DRILLING METHOD Observation Pit AT TIME OF DRILLING
LOGGED BY RF CHECKED BY RF AT END OF DRILLING
NOTES Surface Elevation is approximate. AFTER DRILLING ---
o DEPTH
o (ft)
SAMPLE TYPE
NUMBER
ui
v
ui
GRAPHIC
LOG I
MATERIAL DESCRIPTION
2.5
OL
`'—'' ^`
='' a='
.4 .•
(OL) 0 to 8-inches, Strong brown (7.5YR4/4) sandy loam, Horizon Ap
0.7 776.3
SM
:
(SM) 8 to 32-inches, Strong brown (7.5YR4/6) silt loam, Horizon B
2.7 774.3
5.0
SP-
SM
(SP-SM) 32 to 79-inches, Reddish brown (5YR4/4) loamy sand, Horizon B/C
6.6 770.4
7.5
SP-.:.
SM:
..
(SP-SM) 79 to 108-inches, Yellowish red (5YR5/6) sandy loam, Horizon C
9.0 768.0
Bottom of borehole at 9.0 feet.

<12S>
Water Quality Peak
Flow
<Subca>
Post-Dev 1 C
Reach
Link
2P
Sand Filter
Routing Diagram for 7544-Sand Filter
Prepared by {enter your company name here}, Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Printed 5/19/2021
Page 2
Project Notes
Copied 6 events from Charlotte 6-hr storm

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Area Listing (all nodes)
Area CN Description
(acres) (subcatchment-numbers)
5.600 85 (1S)
5.600 96 (12S)
11.200 91 TOTAL AREA
Printed 5/19/2021
Page 3

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Soil Listing (all nodes)
Area Soil Subcatchment
(acres) Group Numbers
0.000 HSG A
0.000 HSG B
0.000 HSG C
0.000 HSG D
11.200 Other 1S, 12S
11.200 TOTAL AREA
Printed 5/19/2021
Page 4

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Ground Covers (all nodes)
Printed 5/19/2021
Page 5
HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment
(acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers
0.000 0.000 0.000 0.000 11.200 11.200 1S, 12S
0.000 0.000 0.000 0.000 11.200 11.200 TOTAL
AREA

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Pipe Listing (all nodes)
Printed 5/19/2021
Page 6
Line# Node In -Invert Out -Invert Length Slope n Diam/Width Height Inside -Fill
Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches)
1 2P
776.50 775.70
40.0 0.0200 0.013 15.0
0.0 0.0

7544-Sand Filter Charlotte 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 7
Time span=0.00-120.00 hrs, dt=0.05 hrs, 2401 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1 S: Post-Dev 1 C Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=0.17"
Tc=5.0 min CN=85 Runoff=1.90 cfs 0.081 af
Subcatchment 12S: Water Quality Peak Flow Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=0.63"
Tc=5.0 min CN=96 Runoff=8.04 cfs 0.294 af
Pond 2P: Sand Filter Peak Elev=780.30' Storage=0.071 af Inflow=1.90 cfs 0.081 af
Primary=0.05 cfs 0.081 af Secondary=0.00 cfs 0.000 af Outflow=0.05 cfs 0.081 af
Total Runoff Area = 11.200 ac Runoff Volume = 0.375 af Average Runoff Depth = 0.40"
100.00% Pervious = 11.200 ac 0.00% Impervious = 0.000 ac

7544-Sand Filter Charlotte 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 8
Summary for Subcatchment 1 S: Post-Dev 1 C
[49] Hint: Tc<2dt may require smaller dt
Runoff = 1.90 cfs @ 3.19 hrs, Volume=
0.081 af, Depth= 0.17"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Charlotte 6-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
5.600 85
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
0
LL
5.0 Direct Entry,
Subcatchment 1 S: Post-Dev 1 C
Hydrograph
1.90 cfs
v
/
Charlotte 6- r 1-inch
Rainfall=1.00"
IRinbff Area=5.600 ad
RIn9ff Volume=0.981 of
HRunr ID p h70.I17"
Tc=5.0 min
6IVL85
o
. . . . . . . . . . . . . . . . . . . . . . .
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
❑ Runoff

7544-Sand Filter Charlotte 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 9
Hydrograph for Subcatchment 1 S: Post-Dev 1 C
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.17 0.00 0.00
5.00 0.96 0.15 0.14
7.50 1.00 0.17 0.00
10.00 1.00 0.17 0.00
12.50 1.00 0.17 0.00
15.00 1.00 0.17 0.00
17.50 1.00 0.17 0.00
20.00 1.00 0.17 0.00
22.50 1.00 0.17 0.00
25.00 1.00 0.17 0.00
27.50 1.00 0.17 0.00
30.00 1.00 0.17 0.00
32.50 1.00 0.17 0.00
35.00 1.00 0.17 0.00
37.50 1.00 0.17 0.00
40.00 1.00 0.17 0.00
42.50 1.00 0.17 0.00
45.00 1.00 0.17 0.00
47.50 1.00 0.17 0.00
50.00 1.00 0.17 0.00
52.50 1.00 0.17 0.00
55.00 1.00 0.17 0.00
57.50 1.00 0.17 0.00
60.00 1.00 0.17 0.00
62.50 1.00 0.17 0.00
65.00 1.00 0.17 0.00
67.50 1.00 0.17 0.00
70.00 1.00 0.17 0.00
72.50 1.00 0.17 0.00
75.00 1.00 0.17 0.00
77.50 1.00 0.17 0.00
80.00 1.00 0.17 0.00
82.50 1.00 0.17 0.00
85.00 1.00 0.17 0.00
87.50 1.00 0.17 0.00
90.00 1.00 0.17 0.00
92.50 1.00 0.17 0.00
95.00 1.00 0.17 0.00
97.50 1.00 0.17 0.00
100.00 1.00 0.17 0.00
102.50 1.00 0.17 0.00
105.00 1.00 0.17 0.00
107.50 1.00 0.17 0.00
110.00 1.00 0.17 0.00
112.50 1.00 0.17 0.00
115.00 1.00 0.17 0.00
117.50 1.00 0.17 0.00
120.00 1.00 0.17 0.00

7544-Sand Filter Charlotte 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 10
Summary for Subcatchment 12S: Water Quality Peak Flow
[49] Hint: Tc<2dt may require smaller dt
Runoff = 8.04 cfs @ 3.15 hrs, Volume= 0.294 af, Depth= 0.63"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Charlotte 6-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
5.600 96
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 12S: Water Quality Peak Flow
Hydrograph
9
8.04 cfs
/
/
Charlotte 6--r'�-i�
Rainfal1=T.0"
IRi nbfArea=5.600 arc
Rin9ff VOlumie=0.?94 f
H !Run9ff Dep h=0.63"
Tc=5.0 m i n
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
• Runoff

7544-Sand Filter Charlotte 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 11
Hydrograph for Subcatchment 12S: Water Quality Peak Flow
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.17 0.02 0.24
5.00 0.96 0.59 0.29
7.50 1.00 0.63 0.00
10.00 1.00 0.63 0.00
12.50 1.00 0.63 0.00
15.00 1.00 0.63 0.00
17.50 1.00 0.63 0.00
20.00 1.00 0.63 0.00
22.50 1.00 0.63 0.00
25.00 1.00 0.63 0.00
27.50 1.00 0.63 0.00
30.00 1.00 0.63 0.00
32.50 1.00 0.63 0.00
35.00 1.00 0.63 0.00
37.50 1.00 0.63 0.00
40.00 1.00 0.63 0.00
42.50 1.00 0.63 0.00
45.00 1.00 0.63 0.00
47.50 1.00 0.63 0.00
50.00 1.00 0.63 0.00
52.50 1.00 0.63 0.00
55.00 1.00 0.63 0.00
57.50 1.00 0.63 0.00
60.00 1.00 0.63 0.00
62.50 1.00 0.63 0.00
65.00 1.00 0.63 0.00
67.50 1.00 0.63 0.00
70.00 1.00 0.63 0.00
72.50 1.00 0.63 0.00
75.00 1.00 0.63 0.00
77.50 1.00 0.63 0.00
80.00 1.00 0.63 0.00
82.50 1.00 0.63 0.00
85.00 1.00 0.63 0.00
87.50 1.00 0.63 0.00
90.00 1.00 0.63 0.00
92.50 1.00 0.63 0.00
95.00 1.00 0.63 0.00
97.50 1.00 0.63 0.00
100.00 1.00 0.63 0.00
102.50 1.00 0.63 0.00
105.00 1.00 0.63 0.00
107.50 1.00 0.63 0.00
110.00 1.00 0.63 0.00
112.50 1.00 0.63 0.00
115.00 1.00 0.63 0.00
117.50 1.00 0.63 0.00
120.00 1.00 0.63 0.00

7544-Sand Filter Charlotte 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 12
Summary for Pond 2P: Sand Filter
Inflow Area = 5.600 ac, 0.00% Impervious, Inflow Depth = 0.17" for 1-inch event
Inflow = 1.90 cfs @ 3.19 hrs, Volume= 0.081 af
Outflow = 0.05 cfs @ 6.08 hrs, Volume= 0.081 af, Atten= 98%, Lag= 173.3 min
Primary = 0.05 cfs @ 6.08 hrs, Volume= 0.081 af
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 780.30' @ 6.08 hrs Surf.Area= 0.064 ac Storage= 0.071 af
Plug -Flow detention time= 922.6 min calculated for 0.081 af (100% of inflow)
Center -of -Mass det. time= 922.5 min (1,153.4 - 230.9 )
Volume Invert Avail.Storage Storage Description
#1 779.00' 0.364 af Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
779.00 0.045 0.000 0.000
780.00 0.060 0.052 0.052
781.00 0.075 0.068 0.120
782.00 0.093 0.084 0.204
783.00 0.111 0.102 0.306
783.50 0.121 0.058 0.364
Device Routing Invert Outlet Devices
#1 Primary 776.50' 15.0" Round RCP_Round 15"
L= 40.0' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 776.50' / 775.70' S= 0.0200 '/' Cc= 0.900
n= 0.013, Flow Area= 1.23 sf
#2 Device 1 779.00' Special & User -Defined
Head (feet) 0.00 1.00 2.00 3.00 4.50
Disch. (cfs) 0.000 0.041 0.057 0.073 0.097
#3 Device 1 780.50' 48.0" x 48.0" Horiz. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Secondary 782.00' 15.0' long x 10.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Primary OutFlow Max=0.05 cfs @ 6.08 hrs HW=780.30' (Free Discharge)
4-1=RCP_Round 15" (Passes 0.05 cfs of 12.34 cfs potential flow)
12=Special & User -Defined (Custom Controls 0.05 cfs)
3=Orifice/Grate ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=779.00' (Free Discharge)
4=Emergency Spillway ( Controls 0.00 cfs)

7544-Sand Filter Charlotte 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 13
Pond 2P: Sand Filter
Hydrograph
A
1.90 cfs
nn�rf
0.05 cfs
0.0 cfs
0 V////.
783
782
m
m
0
> 781
m
w
780
779
I%fiow AreilJ5.600 ac
Peak EIev=780.30'
Storage=0.071 of
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
Pond 2P: Sand Filter
Stage -Discharge
0
10 20 30
40 50
Discharge (cfs)
60
70
80
90
❑ Inflow
❑ Outflow
❑ Primary
❑ Secondary
❑ Total
❑ Primary
❑ Secondary

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation (feet)
Pond 2P: Sand Filter
Stage -Area -Storage
Surface/Horizontal/Wetted Area (acres)
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09
Charlotte 6-hr 1-inch Rainfall=1.00"
Printed 5/19/2021
Page 14
0.1
0.11
0.12
783-'
782 '
781-
780-
779
II
II
II
I I II
I I I
I I I II
II I I I II
Ji
K K... ...K...K...K. .. K... ...K. .. ...K. .. .../
0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36
Storage (acre-feet)
Surface
❑ Storage

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Time Inflow
(hours) (cfs)
0.00 0.00
2.50 0.00
5.00 0.14
7.50 0.00
10.00 0.00
12.50 0.00
15.00 0.00
17.50 0.00
20.00 0.00
22.50 0.00
25.00 0.00
27.50 0.00
30.00 0.00
32.50 0.00
35.00 0.00
37.50 0.00
40.00 0.00
42.50 0.00
45.00 0.00
47.50 0.00
50.00 0.00
52.50 0.00
55.00 0.00
57.50 0.00
60.00 0.00
62.50 0.00
65.00 0.00
67.50 0.00
70.00 0.00
72.50 0.00
75.00 0.00
77.50 0.00
80.00 0.00
82.50 0.00
85.00 0.00
87.50 0.00
90.00 0.00
92.50 0.00
95.00 0.00
97.50 0.00
100.00 0.00
102.50 0.00
105.00 0.00
107.50 0.00
110.00 0.00
112.50 0.00
115.00 0.00
117.50 0.00
120.00 0.00
Hydrograph for Pond 2P: Sand Filter
Storage
(acre-feet)
0.000
0.000
0.065
0.066
0.057
0.049
0.041
0.035
0.029
0.025
0.021
0.017
0.015
0.012
0.010
0.008
0.007
0.006
0.005
0.004
0.003
0.003
0.002
0.002
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
Elevation
(feet)
779.00
779.00
780.20
780.22
780.07
779.93
779.81
779.69
779.59
779.51
779.43
779.36
779.31
779.26
779.22
779.18
779.15
779.13
779.11
779.09
779.07
779.06
779.05
779.04
779.04
779.03
779.02
779.02
779.02
779.01
779.01
779.01
779.01
779.01
779.01
779.00
779.00
779.00
779.00
779.00
779.00
779.00
779.00
779.00
779.00
779.00
779.00
779.00
779.00
Outflow
(cfs)
0.00
0.00
0.04
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Primary
(cfs)
0.00
0.00
0.04
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Charlotte 6-hr 1-inch Rainfall=1.00"
Printed 5/19/2021
Page 15

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation Discharge
(feet) (cfs)
779.00 0.00
779.05 0.00
779.10 0.00
779.15 0.01
779.20 0.01
779.25 0.01
779.30 0.01
779.35 0.01
779.40 0.02
779.45 0.02
779.50 0.02
779.55 0.02
779.60 0.02
779.65 0.03
779.70 0.03
779.75 0.03
779.80 0.03
779.85 0.03
779.90 0.04
779.95 0.04
780.00 0.04
780.05 0.04
780.10 0.04
780.15 0.04
780.20 0.04
780.25 0.04
780.30 0.05
780.35 0.05
780.40 0.05
780.45 0.05
780.50 0.05
780.55 0.63
780.60 1.71
780.65 3.09
780.70 4.73
780.75 6.59
780.80 8.65
780.85 10.89
780.90 13.29
780.95 13.49
781.00 13.57
781.05 13.65
781.10 13.74
781.15 13.82
781.20 13.90
781.25 13.98
781.30 14.06
781.35 14.15
781.40 14.23
781.45 14.30
781.50 14.38
781.55 14.46
781.60 14.54
Stage -Discharge for Pond 2P: Sand Filter
Primary
(cfs)
0.00
0.00
0.00
0.01
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.02
0.02
0.03
0.03
0.03
0.03
0.03
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.05
0.05
0.05
0.05
0.05
0.63
1.71
3.09
4.73
6.59
8.65
10.89
13.29
13.49
13.57
13.65
13.74
13.82
13.90
13.98
14.06
14.15
14.23
14.30
14.38
14.46
14.54
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Elevation Discharge
(feet) (cfs)
781.65 14.62
781.70 14.70
781.75 14.77
781.80 14.85
781.85 14.93
781.90 15.00
781.95 15.08
782.00 15.15
782.05 15.65
782.10 16.48
782.15 17.55
782.20 18.79
782.25 20.23
782.30 21.82
782.35 23.57
782.40 25.46
782.45 27.57
782.50 29.83
782.55 32.26
782.60 34.85
782.65 37.30
782.70 39.85
782.75 42.47
782.80 45.18
782.85 47.97
782.90 50.84
782.95 53.78
783.00 56.79
783.05 59.95
783.10 63.19
783.15 66.51
783.20 69.90
783.25 73.21
783.30 76.58
783.35 80.00
783.40 83.47
783.45 86.92
783.50 90.42
Primary
(cfs)
14.62
14.70
14.77
14.85
14.93
15.00
15.08
15.15
15.23
15.30
15.38
15.45
15.52
15.60
15.67
15.74
15.81
15.89
15.96
16.03
16.10
16.17
16.24
16.31
16.38
16.45
16.52
16.59
16.66
16.72
16.79
16.86
16.93
16.99
17.06
17.13
17.19
17.26
Charlotte 6-hr 1-inch Rainfall=1.00"
Printed 5/19/2021
Page 16
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.42
1.18
2.17
3.34
4.70
6.22
7.90
9.71
11.75
13.95
16.31
18.82
21.20
23.68
26.23
28.87
31.59
34.39
37.26
40.20
43.29
46.46
49.71
53.04
56.29
59.59
62.94
66.34
69.73
73.16

7544-Sand Filter Charlotte 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 17
Stage -Area -Storage for Pond 2P: Sand Filter
Elevation Surface Storage Elevation Surface Storage
(feet) (acres) (acre-feet) (feet) (acres) (acre-feet)
779.00 0.045 0.000 781.65 0.087 0.173
779.05 0.046 0.002 781.70 0.088 0.177
779.10 0.047 0.005 781.75 0.088 0.181
779.15 0.047 0.007 781.80 0.089 0.186
779.20 0.048 0.009 781.85 0.090 0.190
779.25 0.049 0.012 781.90 0.091 0.195
779.30 0.049 0.014 781.95 0.092 0.199
779.35 0.050 0.017 782.00 0.093 0.204
779.40 0.051 0.019 782.05 0.094 0.209
779.45 0.052 0.022 782.10 0.095 0.213
779.50 0.052 0.024 782.15 0.096 0.218
779.55 0.053 0.027 782.20 0.097 0.223
779.60 0.054 0.030 782.25 0.098 0.228
779.65 0.055 0.032 782.30 0.098 0.233
779.70 0.056 0.035 782.35 0.099 0.238
779.75 0.056 0.038 782.40 0.100 0.243
779.80 0.057 0.041 782.45 0.101 0.248
779.85 0.058 0.044 782.50 0.102 0.253
779.90 0.058 0.047 782.55 0.103 0.258
779.95 0.059 0.050 782.60 0.104 0.263
780.00 0.060 0.052 782.65 0.105 0.268
780.05 0.061 0.056 782.70 0.106 0.274
780.10 0.062 0.059 782.75 0.106 0.279
780.15 0.062 0.062 782.80 0.107 0.284
780.20 0.063 0.065 782.85 0.108 0.290
780.25 0.064 0.068 782.90 0.109 0.295
780.30 0.064 0.071 782.95 0.110 0.300
780.35 0.065 0.074 783.00 0.111 0.306
780.40 0.066 0.078 783.05 0.112 0.312
780.45 0.067 0.081 783.10 0.113 0.317
780.50 0.068 0.084 783.15 0.114 0.323
780.55 0.068 0.088 783.20 0.115 0.329
780.60 0.069 0.091 783.25 0.116 0.334
780.65 0.070 0.095 783.30 0.117 0.340
780.70 0.071 0.098 783.35 0.118 0.346
780.75 0.071 0.102 783.40 0.119 0.352
780.80 0.072 0.105 783.45 0.120 0.358
780.85 0.073 0.109 783.50 0.121 0.364
780.90 0.073 0.113
780.95 0.074 0.116
781.00 0.075 0.120
781.05 0.076 0.124
781.10 0.077 0.128
781.15 0.078 0.131
781.20 0.079 0.135
781.25 0.079 0.139
781.30 0.080 0.143
781.35 0.081 0.147
781.40 0.082 0.151
781.45 0.083 0.156
781.50 0.084 0.160
781.55 0.085 0.164
781.60 0.086 0.168

7544-Sand Filter Type 11 24-hr 1-yr 24hr Rainfall=2.81"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 18
Time span=0.00-120.00 hrs, dt=0.05 hrs, 2401 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1 S: Post-Dev 1 C Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=1.43"
Tc=5.0 min CN=85 Runoff=14.39 cfs 0.667 af
Subcatchment 12S: Water Quality Peak Flow Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=2.37"
Tc=5.0 min CN=96 Runoff=21.56 cfs 1.104 of
Pond 2P: Sand Filter Peak Elev=780.93' Storage=0.115 af Inflow=14.39 cfs 0.667 af
Primary=13.60 cfs 0.667 af Secondary=0.00 cfs 0.000 af Outflow=13.60 cfs 0.667 af
Total Runoff Area = 11.200 ac Runoff Volume = 1.771 af Average Runoff Depth = 1.90"
100.00% Pervious = 11.200 ac 0.00% Impervious = 0.000 ac

7544-Sand Filter Type II 24-hr 1-yr 24hr Rainfall=2.81 "
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 19
Summary for Subcatchment 1 S: Post-Dev 1 C
[49] Hint: Tc<2dt may require smaller dt
Runoff = 14.39 cfs @ 11.96 hrs, Volume=
0.667 af, Depth= 1.43"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24hr Rainfall=2.81"
Area (ac) CN Description
5.600 85
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 1 S: Post-Dev 1 C
Hydrograph
16/
15/ 1
1
14.39 cfs
14/
13/ 1
12/
11 /
10 1
w 9/
8/L
3
LL 7/
6/
5/
/_
3/1
2/
1/:40////
0ff�i
/
▪ fi
1 - _L1r124hi-R1a+nf-i11=2.1" -
1 rt 1RU Hoff AI-ea=5.600 -
1 _L LIB t
1 fi
14
- 1 4n9ff' V-4/14mle7-0. 7-41f -
1 c=5. min
Irt�l fit 1L=
14 I-1 +1 1 -
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
Time (hours)
85 90 95 100 105 110 115 120
• Runoff

7544-Sand Filter Type 11 24-hr 1-yr 24hr Rainfall=2.81"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 20
Hydrograph for Subcatchment 1 S: Post-Dev 1 C
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.08 0.00 0.00
5.00 0.18 0.00 0.00
7.50 0.31 0.00 0.00
10.00 0.51 0.01 0.09
12.50 2.07 0.84 1.23
15.00 2.40 1.10 0.38
17.50 2.56 1.23 0.25
20.00 2.68 1.32 0.17
22.50 2.76 1.39 0.15
25.00 2.81 1.43 0.00
27.50 2.81 1.43 0.00
30.00 2.81 1.43 0.00
32.50 2.81 1.43 0.00
35.00 2.81 1.43 0.00
37.50 2.81 1.43 0.00
40.00 2.81 1.43 0.00
42.50 2.81 1.43 0.00
45.00 2.81 1.43 0.00
47.50 2.81 1.43 0.00
50.00 2.81 1.43 0.00
52.50 2.81 1.43 0.00
55.00 2.81 1.43 0.00
57.50 2.81 1.43 0.00
60.00 2.81 1.43 0.00
62.50 2.81 1.43 0.00
65.00 2.81 1.43 0.00
67.50 2.81 1.43 0.00
70.00 2.81 1.43 0.00
72.50 2.81 1.43 0.00
75.00 2.81 1.43 0.00
77.50 2.81 1.43 0.00
80.00 2.81 1.43 0.00
82.50 2.81 1.43 0.00
85.00 2.81 1.43 0.00
87.50 2.81 1.43 0.00
90.00 2.81 1.43 0.00
92.50 2.81 1.43 0.00
95.00 2.81 1.43 0.00
97.50 2.81 1.43 0.00
100.00 2.81 1.43 0.00
102.50 2.81 1.43 0.00
105.00 2.81 1.43 0.00
107.50 2.81 1.43 0.00
110.00 2.81 1.43 0.00
112.50 2.81 1.43 0.00
115.00 2.81 1.43 0.00
117.50 2.81 1.43 0.00
120.00 2.81 1.43 0.00

7544-Sand Filter Type II 24-hr 1-yr 24hr Rainfall=2.81 "
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 21
Summary for Subcatchment 12S: Water Quality Peak Flow
[49] Hint: Tc<2dt may require smaller dt
Runoff = 21.56 cfs @ 11.95 hrs, Volume= 1.104 af, Depth= 2.37"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 1-yr 24hr Rainfall=2.81"
Area (ac) CN Description
5.600 96
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 12S: Water Quality Peak Flow
Hydrograph
24�
23V 21.56 cfs
22�I
21�
20
19I1
18iv
17,
16!
15
w lay
13�
3 121
0 11Z
LL191/ I
8
7
6
54-7
/
3
2V,L
1
II-
4
141..11.2 1 11h 14a-infill .i31�y�
4 iRWno -AIe�6O a.Q ab
n
jRigiP#I V2I .-
I— !11;!rirlDIPIlr'Plii 1
c�5 9 mtn -
I I I c4si
t 1—It I Irt 1—I-
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
• Runoff

7544-Sand Filter Type 11 24-hr 1-yr 24hr Rainfall=2.81"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 22
Hydrograph for Subcatchment 12S: Water Quality Peak Flow
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.08 0.00 0.00
5.00 0.18 0.02 0.08
7.50 0.31 0.08 0.19
10.00 0.51 0.21 0.46
12.50 2.07 1.64 1.61
15.00 2.40 1.96 0.47
17.50 2.56 2.12 0.30
20.00 2.68 2.23 0.21
22.50 2.76 2.32 0.18
25.00 2.81 2.37 0.00
27.50 2.81 2.37 0.00
30.00 2.81 2.37 0.00
32.50 2.81 2.37 0.00
35.00 2.81 2.37 0.00
37.50 2.81 2.37 0.00
40.00 2.81 2.37 0.00
42.50 2.81 2.37 0.00
45.00 2.81 2.37 0.00
47.50 2.81 2.37 0.00
50.00 2.81 2.37 0.00
52.50 2.81 2.37 0.00
55.00 2.81 2.37 0.00
57.50 2.81 2.37 0.00
60.00 2.81 2.37 0.00
62.50 2.81 2.37 0.00
65.00 2.81 2.37 0.00
67.50 2.81 2.37 0.00
70.00 2.81 2.37 0.00
72.50 2.81 2.37 0.00
75.00 2.81 2.37 0.00
77.50 2.81 2.37 0.00
80.00 2.81 2.37 0.00
82.50 2.81 2.37 0.00
85.00 2.81 2.37 0.00
87.50 2.81 2.37 0.00
90.00 2.81 2.37 0.00
92.50 2.81 2.37 0.00
95.00 2.81 2.37 0.00
97.50 2.81 2.37 0.00
100.00 2.81 2.37 0.00
102.50 2.81 2.37 0.00
105.00 2.81 2.37 0.00
107.50 2.81 2.37 0.00
110.00 2.81 2.37 0.00
112.50 2.81 2.37 0.00
115.00 2.81 2.37 0.00
117.50 2.81 2.37 0.00
120.00 2.81 2.37 0.00

7544-Sand Filter Type 11 24-hr 1-yr 24hr Rainfall=2.81"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 23
Summary for Pond 2P: Sand Filter
Inflow Area = 5.600 ac, 0.00% Impervious, Inflow Depth = 1.43" for 1-yr 24hr event
Inflow = 14.39 cfs @ 11.96 hrs, Volume= 0.667 af
Outflow = 13.60 cfs @ 11.98 hrs, Volume= 0.667 af, Atten= 5%, Lag= 1.3 min
Primary = 13.60 cfs @ 11.98 hrs, Volume= 0.667 af
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 780.93' @ 11.98 hrs Surf.Area= 0.074 ac Storage= 0.115 af
Plug -Flow detention time= 218.0 min calculated for 0.667 af (100% of inflow)
Center -of -Mass det. time= 219.9 min (1,047.9 - 827.9 )
Volume Invert Avail.Storage Storage Description
#1 779.00' 0.364 af Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
779.00 0.045 0.000 0.000
780.00 0.060 0.052 0.052
781.00 0.075 0.068 0.120
782.00 0.093 0.084 0.204
783.00 0.111 0.102 0.306
783.50 0.121 0.058 0.364
Device Routing Invert Outlet Devices
#1 Primary 776.50' 15.0" Round RCP_Round 15"
L= 40.0' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 776.50' / 775.70' S= 0.0200 '/' Cc= 0.900
n= 0.013, Flow Area= 1.23 sf
#2 Device 1 779.00' Special & User -Defined
Head (feet) 0.00 1.00 2.00 3.00 4.50
Disch. (cfs) 0.000 0.041 0.057 0.073 0.097
#3 Device 1 780.50' 48.0" x 48.0" Horiz. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Secondary 782.00' 15.0' long x 10.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Primary OutFlow Max=13.42 cfs @ 11.98 hrs HW=780.91' (Free Discharge)
4-1=RCP_Round 15" (Barrel Controls 13.42 cfs @ 10.94 fps)
12=Special & User -Defined (Passes < 0.06 cfs potential flow)
3=Orifice/Grate (Passes < 13.86 cfs potential flow)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=779.00' (Free Discharge)
4=Emergency Spillway ( Controls 0.00 cfs)

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
16/
15/
14/
13
12
11.
10/
9 /
6/
5.
4.
3.
2/
Pond 2P: Sand Filter
Hydrograph
Type 11 24-hr 1-yr 24hr Rainfall=2.81 "
Printed 5/19/2021
Page 24
4.39 cfs
/r11 Rn f€l .I
13.60 cfs f
/ I
/
/
/
/
0.00 cfs
0
////////
lbfI�nr�4%e �6 0
Peak EIev=780.93'
Story e*91.1-t5-af -
- L
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
783
782
m
0
> 781
m
w
780
779
Pond 2P: Sand Filter
Stage -Discharge
0
10 20 30
40 50
Discharge (cfs)
60
70
80
90
■ Inflow
• Outflow
0 Primary
❑ Secondary
❑ Total
❑ Primary
❑ Secondary

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation (feet)
Pond 2P: Sand Filter
Stage -Area -Storage
Surface/Horizontal/Wetted Area (acres)
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09
Type 11 24-hr 1-yr 24hr Rainfall=2.81 "
Printed 5/19/2021
Page 25
0.1
0.11
0.12
783-'
782 '
781-
780-
779
II
II
II
I I II
I I I
I I I II
II I I I II
Ji
K K... ...K...K...K. .. K... ...K. .. ...K. .. .../
0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36
Storage (acre-feet)
Surface
❑ Storage

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Time Inflow
(hours) (cfs)
0.00 0.00
2.50 0.00
5.00 0.00
7.50 0.00
10.00 0.09
12.50 1.23
15.00 0.38
17.50 0.25
20.00 0.17
22.50 0.15
25.00 0.00
27.50 0.00
30.00 0.00
32.50 0.00
35.00 0.00
37.50 0.00
40.00 0.00
42.50 0.00
45.00 0.00
47.50 0.00
50.00 0.00
52.50 0.00
55.00 0.00
57.50 0.00
60.00 0.00
62.50 0.00
65.00 0.00
67.50 0.00
70.00 0.00
72.50 0.00
75.00 0.00
77.50 0.00
80.00 0.00
82.50 0.00
85.00 0.00
87.50 0.00
90.00 0.00
92.50 0.00
95.00 0.00
97.50 0.00
100.00 0.00
102.50 0.00
105.00 0.00
107.50 0.00
110.00 0.00
112.50 0.00
115.00 0.00
117.50 0.00
120.00 0.00
Hydrograph for Pond 2P: Sand Filter
Storage
(acre-feet)
0.000
0.000
0.000
0.000
0.005
0.090
0.087
0.086
0.085
0.085
0.081
0.071
0.062
0.053
0.045
0.038
0.032
0.027
0.023
0.019
0.016
0.014
0.011
0.009
0.008
0.007
0.005
0.005
0.004
0.003
0.003
0.002
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
Elevation
(feet)
779.00
779.00
779.00
779.00
779.11
780.58
780.53
780.52
780.51
780.51
780.45
780.30
780.16
780.01
779.88
779.76
779.65
779.56
779.47
779.40
779.34
779.29
779.24
779.20
779.17
779.14
779.12
779.10
779.08
779.07
779.06
779.05
779.04
779.03
779.03
779.02
779.02
779.02
779.01
779.01
779.01
779.01
779.01
779.01
779.00
779.00
779.00
779.00
779.00
Outflow
(cfs)
0.00
0.00
0.00
0.00
0.00
1.31
0.38
0.25
0.17
0.15
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Primary
(cfs)
0.00
0.00
0.00
0.00
0.00
1.31
0.38
0.25
0.17
0.15
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Type 11 24-hr 1-yr 24hr Rainfall=2.81 "
Printed 5/19/2021
Page 26

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation Discharge
(feet) (cfs)
779.00 0.00
779.05 0.00
779.10 0.00
779.15 0.01
779.20 0.01
779.25 0.01
779.30 0.01
779.35 0.01
779.40 0.02
779.45 0.02
779.50 0.02
779.55 0.02
779.60 0.02
779.65 0.03
779.70 0.03
779.75 0.03
779.80 0.03
779.85 0.03
779.90 0.04
779.95 0.04
780.00 0.04
780.05 0.04
780.10 0.04
780.15 0.04
780.20 0.04
780.25 0.04
780.30 0.05
780.35 0.05
780.40 0.05
780.45 0.05
780.50 0.05
780.55 0.63
780.60 1.71
780.65 3.09
780.70 4.73
780.75 6.59
780.80 8.65
780.85 10.89
780.90 13.29
780.95 13.49
781.00 13.57
781.05 13.65
781.10 13.74
781.15 13.82
781.20 13.90
781.25 13.98
781.30 14.06
781.35 14.15
781.40 14.23
781.45 14.30
781.50 14.38
781.55 14.46
781.60 14.54
Stage -Discharge for Pond 2P: Sand Filter
Primary
(cfs)
0.00
0.00
0.00
0.01
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.02
0.02
0.03
0.03
0.03
0.03
0.03
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.05
0.05
0.05
0.05
0.05
0.63
1.71
3.09
4.73
6.59
8.65
10.89
13.29
13.49
13.57
13.65
13.74
13.82
13.90
13.98
14.06
14.15
14.23
14.30
14.38
14.46
14.54
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Elevation Discharge
(feet) (cfs)
781.65 14.62
781.70 14.70
781.75 14.77
781.80 14.85
781.85 14.93
781.90 15.00
781.95 15.08
782.00 15.15
782.05 15.65
782.10 16.48
782.15 17.55
782.20 18.79
782.25 20.23
782.30 21.82
782.35 23.57
782.40 25.46
782.45 27.57
782.50 29.83
782.55 32.26
782.60 34.85
782.65 37.30
782.70 39.85
782.75 42.47
782.80 45.18
782.85 47.97
782.90 50.84
782.95 53.78
783.00 56.79
783.05 59.95
783.10 63.19
783.15 66.51
783.20 69.90
783.25 73.21
783.30 76.58
783.35 80.00
783.40 83.47
783.45 86.92
783.50 90.42
Primary
(cfs)
14.62
14.70
14.77
14.85
14.93
15.00
15.08
15.15
15.23
15.30
15.38
15.45
15.52
15.60
15.67
15.74
15.81
15.89
15.96
16.03
16.10
16.17
16.24
16.31
16.38
16.45
16.52
16.59
16.66
16.72
16.79
16.86
16.93
16.99
17.06
17.13
17.19
17.26
Type 11 24-hr 1-yr 24hr Rainfall=2.81 "
Printed 5/19/2021
Page 27
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.42
1.18
2.17
3.34
4.70
6.22
7.90
9.71
11.75
13.95
16.31
18.82
21.20
23.68
26.23
28.87
31.59
34.39
37.26
40.20
43.29
46.46
49.71
53.04
56.29
59.59
62.94
66.34
69.73
73.16

7544-Sand Filter Type 11 24-hr 1-yr 24hr Rainfall=2.81"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 28
Stage -Area -Storage for Pond 2P: Sand Filter
Elevation Surface Storage Elevation Surface Storage
(feet) (acres) (acre-feet) (feet) (acres) (acre-feet)
779.00 0.045 0.000 781.65 0.087 0.173
779.05 0.046 0.002 781.70 0.088 0.177
779.10 0.047 0.005 781.75 0.088 0.181
779.15 0.047 0.007 781.80 0.089 0.186
779.20 0.048 0.009 781.85 0.090 0.190
779.25 0.049 0.012 781.90 0.091 0.195
779.30 0.049 0.014 781.95 0.092 0.199
779.35 0.050 0.017 782.00 0.093 0.204
779.40 0.051 0.019 782.05 0.094 0.209
779.45 0.052 0.022 782.10 0.095 0.213
779.50 0.052 0.024 782.15 0.096 0.218
779.55 0.053 0.027 782.20 0.097 0.223
779.60 0.054 0.030 782.25 0.098 0.228
779.65 0.055 0.032 782.30 0.098 0.233
779.70 0.056 0.035 782.35 0.099 0.238
779.75 0.056 0.038 782.40 0.100 0.243
779.80 0.057 0.041 782.45 0.101 0.248
779.85 0.058 0.044 782.50 0.102 0.253
779.90 0.058 0.047 782.55 0.103 0.258
779.95 0.059 0.050 782.60 0.104 0.263
780.00 0.060 0.052 782.65 0.105 0.268
780.05 0.061 0.056 782.70 0.106 0.274
780.10 0.062 0.059 782.75 0.106 0.279
780.15 0.062 0.062 782.80 0.107 0.284
780.20 0.063 0.065 782.85 0.108 0.290
780.25 0.064 0.068 782.90 0.109 0.295
780.30 0.064 0.071 782.95 0.110 0.300
780.35 0.065 0.074 783.00 0.111 0.306
780.40 0.066 0.078 783.05 0.112 0.312
780.45 0.067 0.081 783.10 0.113 0.317
780.50 0.068 0.084 783.15 0.114 0.323
780.55 0.068 0.088 783.20 0.115 0.329
780.60 0.069 0.091 783.25 0.116 0.334
780.65 0.070 0.095 783.30 0.117 0.340
780.70 0.071 0.098 783.35 0.118 0.346
780.75 0.071 0.102 783.40 0.119 0.352
780.80 0.072 0.105 783.45 0.120 0.358
780.85 0.073 0.109 783.50 0.121 0.364
780.90 0.073 0.113
780.95 0.074 0.116
781.00 0.075 0.120
781.05 0.076 0.124
781.10 0.077 0.128
781.15 0.078 0.131
781.20 0.079 0.135
781.25 0.079 0.139
781.30 0.080 0.143
781.35 0.081 0.147
781.40 0.082 0.151
781.45 0.083 0.156
781.50 0.084 0.160
781.55 0.085 0.164
781.60 0.086 0.168

7544-Sand Filter Type 11 24-hr 2-yr Rainfall=3.39"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 29
Time span=0.00-120.00 hrs, dt=0.05 hrs, 2401 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1 S: Post-Dev 1 C Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=1.92"
Tc=5.0 min CN=85 Runoff=19.19 cfs 0.896 af
Subcatchment 12S: Water Quality Peak Flow Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=2.94"
Tc=5.0 min CN=96 Runoff=26.40 cfs 1.370 af
Pond 2P: Sand Filter Peak Elev=781.32' Storage=0.145 af Inflow=19.19 cfs 0.896 af
Primary=14.10 cfs 0.896 af Secondary=0.00 cfs 0.000 af Outflow=14.10 cfs 0.896 af
Total Runoff Area = 11.200 ac Runoff Volume = 2.267 af Average Runoff Depth = 2.43"
100.00% Pervious = 11.200 ac 0.00% Impervious = 0.000 ac

7544-Sand Filter Type 11 24-hr 2-yr Rainfall=3.39"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 30
Summary for Subcatchment 1 S: Post-Dev 1 C
[49] Hint: Tc<2dt may require smaller dt
Runoff = 19.19 cfs @ 11.96 hrs, Volume=
0.896 af, Depth= 1.92"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 2-yr Rainfall=3.39"
Area (ac) CN Description
5.600 85
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 1 S: Post-Dev 1 C
Hydrograph
2141
20V19.19 cfs
19i
18i-/
17/ — I
16i/
15=
14i/
13i/L-
w 12i-< —
11/t-
0 10V/
lL 9J
8/
7/
6/1
5�
34�
2V,I
I�
L
jF
T
� I
I I I 1 I H I —I -
—I rt 1H fi I�� 113d�hr -
y1�f11�3.�39
- 1 H 1ROnbfLAkeA 5.6OO ab -
R471391TV-44114-Thle0- . ¢41f -
min -
rt� l fi l 1 �5�L/x�
V
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
• Runoff

7544-Sand Filter Type 11 24-hr 2-yr Rainfall=3.39"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 31
Hydrograph for Subcatchment 1 S: Post-Dev 1 C
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.10 0.00 0.00
5.00 0.21 0.00 0.00
7.50 0.37 0.00 0.01
10.00 0.61 0.03 0.17
12.50 2.49 1.17 1.59
15.00 2.89 1.50 0.49
17.50 3.09 1.66 0.31
20.00 3.23 1.78 0.22
22.50 3.33 1.87 0.19
25.00 3.39 1.92 0.00
27.50 3.39 1.92 0.00
30.00 3.39 1.92 0.00
32.50 3.39 1.92 0.00
35.00 3.39 1.92 0.00
37.50 3.39 1.92 0.00
40.00 3.39 1.92 0.00
42.50 3.39 1.92 0.00
45.00 3.39 1.92 0.00
47.50 3.39 1.92 0.00
50.00 3.39 1.92 0.00
52.50 3.39 1.92 0.00
55.00 3.39 1.92 0.00
57.50 3.39 1.92 0.00
60.00 3.39 1.92 0.00
62.50 3.39 1.92 0.00
65.00 3.39 1.92 0.00
67.50 3.39 1.92 0.00
70.00 3.39 1.92 0.00
72.50 3.39 1.92 0.00
75.00 3.39 1.92 0.00
77.50 3.39 1.92 0.00
80.00 3.39 1.92 0.00
82.50 3.39 1.92 0.00
85.00 3.39 1.92 0.00
87.50 3.39 1.92 0.00
90.00 3.39 1.92 0.00
92.50 3.39 1.92 0.00
95.00 3.39 1.92 0.00
97.50 3.39 1.92 0.00
100.00 3.39 1.92 0.00
102.50 3.39 1.92 0.00
105.00 3.39 1.92 0.00
107.50 3.39 1.92 0.00
110.00 3.39 1.92 0.00
112.50 3.39 1.92 0.00
115.00 3.39 1.92 0.00
117.50 3.39 1.92 0.00
120.00 3.39 1.92 0.00

7544-Sand Filter Type 11 24-hr 2-yr Rainfall=3.39"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 32
Summary for Subcatchment 12S: Water Quality Peak Flow
[49] Hint: Tc<2dt may require smaller dt
Runoff = 26.40 cfs @ 11.95 hrs, Volume= 1.370 af, Depth= 2.94"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 2-yr Rainfall=3.39"
Area (ac) CN Description
5.600 96
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0
Direct Entry,
Subcatchment 12S: Water Quality Peak Flow
Hydrograph
1
28 26.40 cfs
26Y
2411 _
22Y
20/�
187/L
16/
c 141/
LL12�l
10--/
8Y
4/
2
0
fi
L
1t
� t 711pu14d�1- _
- 1 J L 1fly Rlai�fa%II" -
tRtlirnbff-AIea=5.6@Q -
I _LRu nPfif V2Ittmle7_1. 79 f
I t !I-tliirlipr-tr-1172'P41"
c 5 - min -
- I-L 1_ 1_ L1 1_HaNL9-
- 1- 1—I-1 1- I I rt -
- 1 1_1_ I 1 1—I -
rt 1-
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
• Runoff

7544-Sand Filter Type 11 24-hr 2-yr Rainfall=3.39"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 33
Hydrograph for Subcatchment 12S: Water Quality Peak Flow
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.10 0.00 0.01
5.00 0.21 0.03 0.12
7.50 0.37 0.12 0.26
10.00 0.61 0.30 0.60
12.50 2.49 2.05 1.96
15.00 2.89 2.45 0.57
17.50 3.09 2.64 0.37
20.00 3.23 2.78 0.25
22.50 3.33 2.88 0.22
25.00 3.39 2.94 0.00
27.50 3.39 2.94 0.00
30.00 3.39 2.94 0.00
32.50 3.39 2.94 0.00
35.00 3.39 2.94 0.00
37.50 3.39 2.94 0.00
40.00 3.39 2.94 0.00
42.50 3.39 2.94 0.00
45.00 3.39 2.94 0.00
47.50 3.39 2.94 0.00
50.00 3.39 2.94 0.00
52.50 3.39 2.94 0.00
55.00 3.39 2.94 0.00
57.50 3.39 2.94 0.00
60.00 3.39 2.94 0.00
62.50 3.39 2.94 0.00
65.00 3.39 2.94 0.00
67.50 3.39 2.94 0.00
70.00 3.39 2.94 0.00
72.50 3.39 2.94 0.00
75.00 3.39 2.94 0.00
77.50 3.39 2.94 0.00
80.00 3.39 2.94 0.00
82.50 3.39 2.94 0.00
85.00 3.39 2.94 0.00
87.50 3.39 2.94 0.00
90.00 3.39 2.94 0.00
92.50 3.39 2.94 0.00
95.00 3.39 2.94 0.00
97.50 3.39 2.94 0.00
100.00 3.39 2.94 0.00
102.50 3.39 2.94 0.00
105.00 3.39 2.94 0.00
107.50 3.39 2.94 0.00
110.00 3.39 2.94 0.00
112.50 3.39 2.94 0.00
115.00 3.39 2.94 0.00
117.50 3.39 2.94 0.00
120.00 3.39 2.94 0.00

7544-Sand Filter Type 11 24-hr 2-yr Rainfall=3.39"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 34
Summary for Pond 2P: Sand Filter
Inflow Area = 5.600 ac, 0.00% Impervious, Inflow Depth = 1.92" for 2-yr event
Inflow = 19.19 cfs @ 11.96 hrs, Volume= 0.896 of
Outflow = 14.10 cfs @ 12.01 hrs, Volume= 0.896 af, Atten= 26%, Lag= 3.4 min
Primary = 14.10 cfs @ 12.01 hrs, Volume= 0.896 af
Secondary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 781.32' @ 12.01 hrs Surf.Area= 0.081 ac Storage= 0.145 af
Plug -Flow detention time= 167.4 min calculated for 0.896 af (100% of inflow)
Center -of -Mass det. time= 167.3 min (986.8 - 819.5 )
Volume Invert Avail.Storage Storage Description
#1 779.00' 0.364 af Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
779.00 0.045 0.000 0.000
780.00 0.060 0.052 0.052
781.00 0.075 0.068 0.120
782.00 0.093 0.084 0.204
783.00 0.111 0.102 0.306
783.50 0.121 0.058 0.364
Device Routing Invert Outlet Devices
#1 Primary 776.50' 15.0" Round RCP_Round 15"
L= 40.0' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 776.50' / 775.70' S= 0.0200 '/' Cc= 0.900
n= 0.013, Flow Area= 1.23 sf
#2 Device 1 779.00' Special & User -Defined
Head (feet) 0.00 1.00 2.00 3.00 4.50
Disch. (cfs) 0.000 0.041 0.057 0.073 0.097
#3 Device 1 780.50' 48.0" x 48.0" Horiz. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Secondary 782.00' 15.0' long x 10.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Primary OutFlow Max=14.06 cfs @ 12.01 hrs HW=781.30' (Free Discharge)
4-1=RCP_Round 15" (Barrel Controls 14.06 cfs @ 11.46 fps)
12=Special & User -Defined (Passes < 0.06 cfs potential flow)
3=Orifice/Grate (Passes < 37.25 cfs potential flow)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=779.00' (Free Discharge)
4=Emergency Spillway ( Controls 0.00 cfs)

7544-Sand Filter Type 11 24-hr 2-yr Rainfall=3.39"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 35
21
20=
19=
184/
17i/
16i/
15�
145
131
12
11=
0 10=
LT- 9
71/
61/
/
/
54/
/
3
0.00 cfs /
Pond 2P: Sand Filter
Hydrograph
-
- h I h yak .132
ter' je � 1 5 is -
4 1 1 t
-I
-I
4I
4I
ff
t
l41-l-tl
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
783
782
m
0
> 781
m
w
780
779
Pond 2P: Sand Filter
Stage -Discharge
0
10 20 30
40 50
Discharge (cfs)
60
70
80
90
■ Inflow
■ Outflow
0 Primary
❑ Secondary
❑ Total
❑ Primary
❑ Secondary

7544-Sand Filter Type 11 24-hr 2-yr Rainfall=3.39"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 36
Elevation (feet)
Pond 2P: Sand Filter
Stage -Area -Storage
Surface/Horizontal/Wetted Area (acres)
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09
0.1
0.11
0.12
783-'
782 '
781-
780-
779
II
II
II
I I II
I I I
I I I II
II I I I II
Ji
K K... ...K...K...K. .. K... ...K. .. ...K. .. .../
0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36
Storage (acre-feet)
Surface
❑ Storage

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Time Inflow
(hours) (cfs)
0.00 0.00
2.50 0.00
5.00 0.00
7.50 0.01
10.00 0.17
12.50 1.59
15.00 0.49
17.50 0.31
20.00 0.22
22.50 0.19
25.00 0.00
27.50 0.00
30.00 0.00
32.50 0.00
35.00 0.00
37.50 0.00
40.00 0.00
42.50 0.00
45.00 0.00
47.50 0.00
50.00 0.00
52.50 0.00
55.00 0.00
57.50 0.00
60.00 0.00
62.50 0.00
65.00 0.00
67.50 0.00
70.00 0.00
72.50 0.00
75.00 0.00
77.50 0.00
80.00 0.00
82.50 0.00
85.00 0.00
87.50 0.00
90.00 0.00
92.50 0.00
95.00 0.00
97.50 0.00
100.00 0.00
102.50 0.00
105.00 0.00
107.50 0.00
110.00 0.00
112.50 0.00
115.00 0.00
117.50 0.00
120.00 0.00
Type 11 24-hr 2-yr Rainfall=3.39"
Printed 5/19/2021
Page 37
Hydrograph for Pond 2P: Sand Filter
Storage
(acre-feet)
0.000
0.000
0.000
0.000
0.014
0.091
0.087
0.086
0.086
0.085
0.081
0.071
0.062
0.053
0.045
0.039
0.033
0.027
0.023
0.019
0.016
0.014
0.011
0.009
0.008
0.007
0.005
0.005
0.004
0.003
0.003
0.002
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
Elevation
(feet)
779.00
779.00
779.00
779.00
779.29
780.60
780.54
780.53
780.52
780.52
780.45
780.30
780.16
780.02
779.88
779.76
779.65
779.56
779.47
779.40
779.34
779.29
779.24
779.20
779.17
779.14
779.12
779.10
779.08
779.07
779.06
779.05
779.04
779.03
779.03
779.02
779.02
779.02
779.01
779.01
779.01
779.01
779.01
779.01
779.00
779.00
779.00
779.00
779.00
Outflow
(cfs)
0.00
0.00
0.00
0.00
0.01
1.70
0.49
0.32
0.22
0.20
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Primary
(cfs)
0.00
0.00
0.00
0.00
0.01
1.70
0.49
0.32
0.22
0.20
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation Discharge
(feet) (cfs)
779.00 0.00
779.05 0.00
779.10 0.00
779.15 0.01
779.20 0.01
779.25 0.01
779.30 0.01
779.35 0.01
779.40 0.02
779.45 0.02
779.50 0.02
779.55 0.02
779.60 0.02
779.65 0.03
779.70 0.03
779.75 0.03
779.80 0.03
779.85 0.03
779.90 0.04
779.95 0.04
780.00 0.04
780.05 0.04
780.10 0.04
780.15 0.04
780.20 0.04
780.25 0.04
780.30 0.05
780.35 0.05
780.40 0.05
780.45 0.05
780.50 0.05
780.55 0.63
780.60 1.71
780.65 3.09
780.70 4.73
780.75 6.59
780.80 8.65
780.85 10.89
780.90 13.29
780.95 13.49
781.00 13.57
781.05 13.65
781.10 13.74
781.15 13.82
781.20 13.90
781.25 13.98
781.30 14.06
781.35 14.15
781.40 14.23
781.45 14.30
781.50 14.38
781.55 14.46
781.60 14.54
Type 11 24-hr 2-yr Rainfall=3.39"
Printed 5/19/2021
Page 38
Stage -Discharge for Pond 2P: Sand Filter
Primary
(cfs)
0.00
0.00
0.00
0.01
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.02
0.02
0.03
0.03
0.03
0.03
0.03
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.05
0.05
0.05
0.05
0.05
0.63
1.71
3.09
4.73
6.59
8.65
10.89
13.29
13.49
13.57
13.65
13.74
13.82
13.90
13.98
14.06
14.15
14.23
14.30
14.38
14.46
14.54
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Elevation Discharge
(feet) (cfs)
781.65 14.62
781.70 14.70
781.75 14.77
781.80 14.85
781.85 14.93
781.90 15.00
781.95 15.08
782.00 15.15
782.05 15.65
782.10 16.48
782.15 17.55
782.20 18.79
782.25 20.23
782.30 21.82
782.35 23.57
782.40 25.46
782.45 27.57
782.50 29.83
782.55 32.26
782.60 34.85
782.65 37.30
782.70 39.85
782.75 42.47
782.80 45.18
782.85 47.97
782.90 50.84
782.95 53.78
783.00 56.79
783.05 59.95
783.10 63.19
783.15 66.51
783.20 69.90
783.25 73.21
783.30 76.58
783.35 80.00
783.40 83.47
783.45 86.92
783.50 90.42
Primary
(cfs)
14.62
14.70
14.77
14.85
14.93
15.00
15.08
15.15
15.23
15.30
15.38
15.45
15.52
15.60
15.67
15.74
15.81
15.89
15.96
16.03
16.10
16.17
16.24
16.31
16.38
16.45
16.52
16.59
16.66
16.72
16.79
16.86
16.93
16.99
17.06
17.13
17.19
17.26
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.42
1.18
2.17
3.34
4.70
6.22
7.90
9.71
11.75
13.95
16.31
18.82
21.20
23.68
26.23
28.87
31.59
34.39
37.26
40.20
43.29
46.46
49.71
53.04
56.29
59.59
62.94
66.34
69.73
73.16

7544-Sand Filter Type 11 24-hr 2-yr Rainfall=3.39"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 39
Stage -Area -Storage for Pond 2P: Sand Filter
Elevation Surface Storage Elevation Surface Storage
(feet) (acres) (acre-feet) (feet) (acres) (acre-feet)
779.00 0.045 0.000 781.65 0.087 0.173
779.05 0.046 0.002 781.70 0.088 0.177
779.10 0.047 0.005 781.75 0.088 0.181
779.15 0.047 0.007 781.80 0.089 0.186
779.20 0.048 0.009 781.85 0.090 0.190
779.25 0.049 0.012 781.90 0.091 0.195
779.30 0.049 0.014 781.95 0.092 0.199
779.35 0.050 0.017 782.00 0.093 0.204
779.40 0.051 0.019 782.05 0.094 0.209
779.45 0.052 0.022 782.10 0.095 0.213
779.50 0.052 0.024 782.15 0.096 0.218
779.55 0.053 0.027 782.20 0.097 0.223
779.60 0.054 0.030 782.25 0.098 0.228
779.65 0.055 0.032 782.30 0.098 0.233
779.70 0.056 0.035 782.35 0.099 0.238
779.75 0.056 0.038 782.40 0.100 0.243
779.80 0.057 0.041 782.45 0.101 0.248
779.85 0.058 0.044 782.50 0.102 0.253
779.90 0.058 0.047 782.55 0.103 0.258
779.95 0.059 0.050 782.60 0.104 0.263
780.00 0.060 0.052 782.65 0.105 0.268
780.05 0.061 0.056 782.70 0.106 0.274
780.10 0.062 0.059 782.75 0.106 0.279
780.15 0.062 0.062 782.80 0.107 0.284
780.20 0.063 0.065 782.85 0.108 0.290
780.25 0.064 0.068 782.90 0.109 0.295
780.30 0.064 0.071 782.95 0.110 0.300
780.35 0.065 0.074 783.00 0.111 0.306
780.40 0.066 0.078 783.05 0.112 0.312
780.45 0.067 0.081 783.10 0.113 0.317
780.50 0.068 0.084 783.15 0.114 0.323
780.55 0.068 0.088 783.20 0.115 0.329
780.60 0.069 0.091 783.25 0.116 0.334
780.65 0.070 0.095 783.30 0.117 0.340
780.70 0.071 0.098 783.35 0.118 0.346
780.75 0.071 0.102 783.40 0.119 0.352
780.80 0.072 0.105 783.45 0.120 0.358
780.85 0.073 0.109 783.50 0.121 0.364
780.90 0.073 0.113
780.95 0.074 0.116
781.00 0.075 0.120
781.05 0.076 0.124
781.10 0.077 0.128
781.15 0.078 0.131
781.20 0.079 0.135
781.25 0.079 0.139
781.30 0.080 0.143
781.35 0.081 0.147
781.40 0.082 0.151
781.45 0.083 0.156
781.50 0.084 0.160
781.55 0.085 0.164
781.60 0.086 0.168

7544-Sand Filter Type 1124-hr 10-yr Rainfall=4.96"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 40
Time span=0.00-120.00 hrs, dt=0.05 hrs, 2401 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1 S: Post-Dev 1 C Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=3.33"
Tc=5.0 min CN=85 Runoff=32.52 cfs 1.555 af
Subcatchment 12S: Water Quality Peak Flow Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=4.49"
Tc=5.0 min CN=96 Runoff=39.37 cfs 2.097 af
Pond 2P: Sand Filter Peak Elev=782.46' Storage=0.249 af Inflow=32.52 cfs 1.555 af
Primary=15.83 cfs 1.474 af Secondary=11.91 cfs 0.081 af Outflow=27.74 cfs 1.554 af
Total Runoff Area = 11.200 ac Runoff Volume = 3.651 af Average Runoff Depth = 3.91"
100.00% Pervious = 11.200 ac 0.00% Impervious = 0.000 ac

7544-Sand Filter Type 11 24-hr 10-yr Rainfall=4.96"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 41
Summary for Subcatchment 1 S: Post-Dev 1 C
[49] Hint: Tc<2dt may require smaller dt
Runoff = 32.52 cfs @ 11.95 hrs, Volume=
1.555 af, Depth= 3.33"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 10-yr Rainfall=4.96"
Area (ac) CN Description
5.600 85
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0
36
344 L_32.52 cfs
32/
30�1—
28:
_
26Y1
24=
22/H
20/
o
18/
Li • 16/
14/
12/
10/
8/
6/
4= L
2/
0-
rt
Direct Entry,
Subcatchment 1 S: Post-Dev 1 C
Hydrograph
l l I T 1-11
- fi I —I fi I�� II-�2d-�qr =
- - T h y Raiff II 4.196�' -
RUn- ff--AIea=-5.600 -ab -
TRIM f V#I41Alle!1. f -
L ITnf 1
c=5 0 min
I ITT I IL815_
—1 T I I IT 1- I I 7 1— IT
� T I rt
IT I —I
TIT _
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
• Runoff

7544-Sand Filter Type 1124-hr 10-yr Rainfall=4.96"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 42
Hydrograph for Subcatchment 1 S: Post-Dev 1 C
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.14 0.00 0.00
5.00 0.31 0.00 0.00
7.50 0.54 0.02 0.10
10.00 0.90 0.13 0.44
12.50 3.65 2.14 2.57
15.00 4.23 2.67 0.77
17.50 4.52 2.93 0.50
20.00 4.72 3.11 0.34
22.50 4.88 3.25 0.30
25.00 4.96 3.33 0.00
27.50 4.96 3.33 0.00
30.00 4.96 3.33 0.00
32.50 4.96 3.33 0.00
35.00 4.96 3.33 0.00
37.50 4.96 3.33 0.00
40.00 4.96 3.33 0.00
42.50 4.96 3.33 0.00
45.00 4.96 3.33 0.00
47.50 4.96 3.33 0.00
50.00 4.96 3.33 0.00
52.50 4.96 3.33 0.00
55.00 4.96 3.33 0.00
57.50 4.96 3.33 0.00
60.00 4.96 3.33 0.00
62.50 4.96 3.33 0.00
65.00 4.96 3.33 0.00
67.50 4.96 3.33 0.00
70.00 4.96 3.33 0.00
72.50 4.96 3.33 0.00
75.00 4.96 3.33 0.00
77.50 4.96 3.33 0.00
80.00 4.96 3.33 0.00
82.50 4.96 3.33 0.00
85.00 4.96 3.33 0.00
87.50 4.96 3.33 0.00
90.00 4.96 3.33 0.00
92.50 4.96 3.33 0.00
95.00 4.96 3.33 0.00
97.50 4.96 3.33 0.00
100.00 4.96 3.33 0.00
102.50 4.96 3.33 0.00
105.00 4.96 3.33 0.00
107.50 4.96 3.33 0.00
110.00 4.96 3.33 0.00
112.50 4.96 3.33 0.00
115.00 4.96 3.33 0.00
117.50 4.96 3.33 0.00
120.00 4.96 3.33 0.00

7544-Sand Filter Type 11 24-hr 10-yr Rainfall=4.96"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 43
Summary for Subcatchment 12S: Water Quality Peak Flow
[49] Hint: Tc<2dt may require smaller dt
Runoff = 39.37 cfs @ 11.95 hrs, Volume= 2.097 af, Depth= 4.49"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 10-yr Rainfall=4.96"
Area (ac) CN Description
5.600 96
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 12S: Water Quality Peak Flow
Hydrograph
44/
42� 39.37 cfs
40�
38i-
36��
34� —
32 I
�
30-
2s
26i/
ui 24
—
0 20
LL 18 z
16�
14/z
12i
104<1
s=
6_ —
4��
2i/
0
f-I-[
rt I� -r
- 1 -F h y Rai�fa�ll 4.361"
- rt 1Rtlin-bff-AIea=5.600 at
— 1 - I— l -
c 5 - min -
Irt1-I TI I ]-I-1
1�
I— I —
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
• Runoff

7544-Sand Filter Type 1124-hr 10-yr Rainfall=4.96"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 44
Hydrograph for Subcatchment 12S: Water Quality Peak Flow
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.14 0.01 0.07
5.00 0.31 0.08 0.26
7.50 0.54 0.24 0.45
10.00 0.90 0.54 0.96
12.50 3.65 3.19 2.90
15.00 4.23 3.77 0.85
17.50 4.52 4.06 0.54
20.00 4.72 4.26 0.37
22.50 4.88 4.41 0.33
25.00 4.96 4.49 0.00
27.50 4.96 4.49 0.00
30.00 4.96 4.49 0.00
32.50 4.96 4.49 0.00
35.00 4.96 4.49 0.00
37.50 4.96 4.49 0.00
40.00 4.96 4.49 0.00
42.50 4.96 4.49 0.00
45.00 4.96 4.49 0.00
47.50 4.96 4.49 0.00
50.00 4.96 4.49 0.00
52.50 4.96 4.49 0.00
55.00 4.96 4.49 0.00
57.50 4.96 4.49 0.00
60.00 4.96 4.49 0.00
62.50 4.96 4.49 0.00
65.00 4.96 4.49 0.00
67.50 4.96 4.49 0.00
70.00 4.96 4.49 0.00
72.50 4.96 4.49 0.00
75.00 4.96 4.49 0.00
77.50 4.96 4.49 0.00
80.00 4.96 4.49 0.00
82.50 4.96 4.49 0.00
85.00 4.96 4.49 0.00
87.50 4.96 4.49 0.00
90.00 4.96 4.49 0.00
92.50 4.96 4.49 0.00
95.00 4.96 4.49 0.00
97.50 4.96 4.49 0.00
100.00 4.96 4.49 0.00
102.50 4.96 4.49 0.00
105.00 4.96 4.49 0.00
107.50 4.96 4.49 0.00
110.00 4.96 4.49 0.00
112.50 4.96 4.49 0.00
115.00 4.96 4.49 0.00
117.50 4.96 4.49 0.00
120.00 4.96 4.49 0.00

7544-Sand Filter Type 1124-hr 10-yr Rainfall=4.96"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 45
Summary for Pond 2P: Sand Filter
Inflow Area = 5.600 ac, 0.00% Impervious, Inflow Depth = 3.33" for 10-yr event
Inflow = 32.52 cfs @ 11.95 hrs, Volume= 1.555 af
Outflow = 27.74 cfs @ 12.01 hrs, Volume= 1.554 af, Atten= 15%, Lag= 3.3 min
Primary = 15.83 cfs @ 12.01 hrs, Volume= 1.474 af
Secondary = 11.91 cfs @ 12.01 hrs, Volume= 0.081 af
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 782.46' @ 12.01 hrs Surf.Area= 0.101 ac Storage= 0.249 af
Plug -Flow detention time= 101.4 min calculated for 1.554 af (100% of inflow)
Center -of -Mass det. time= 103.2 min (907.1 - 803.8 )
Volume Invert Avail.Storage Storage Description
#1 779.00' 0.364 af Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
779.00 0.045 0.000 0.000
780.00 0.060 0.052 0.052
781.00 0.075 0.068 0.120
782.00 0.093 0.084 0.204
783.00 0.111 0.102 0.306
783.50 0.121 0.058 0.364
Device Routing Invert Outlet Devices
#1 Primary 776.50' 15.0" Round RCP_Round 15"
L= 40.0' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 776.50' / 775.70' S= 0.0200 '/' Cc= 0.900
n= 0.013, Flow Area= 1.23 sf
#2 Device 1 779.00' Special & User -Defined
Head (feet) 0.00 1.00 2.00 3.00 4.50
Disch. (cfs) 0.000 0.041 0.057 0.073 0.097
#3 Device 1 780.50' 48.0" x 48.0" Horiz. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Secondary 782.00' 15.0' long x 10.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Primary OutFlow Max=15.77 cfs @ 12.01 hrs HW=782.42' (Free Discharge)
4-1=RCP_Round 15" (Barrel Controls 15.77 cfs @ 12.85 fps)
12=Special & User -Defined (Passes < 0.08 cfs potential flow)
3=Orifice/Grate (Passes < 106.72 cfs potential flow)
Secondary OutFlow Max=10.72 cfs @ 12.01 hrs HW=782.43' (Free Discharge)
4=Emergency Spillway (Weir Controls 10.72 cfs @ 1.68 fps)

7544-Sand Filter Type 1124-hr 10-yr Rainfall=4.96"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 46
36=Z
34.
32 V
30 V
28 V
26 V
24V
22 V
f, 20V
18i/
u_ 16=
14=
12�
10:
8=
6-
4-
2=
Pond 2P: Sand Filter
Hydrograph
/ 32.52 cfs
/
/ 27.74 cfs 4
4
4
4
L
- 4
4
4
4
4
4
h-- f6N4ki.16�0 lack -
Peak v1=78,2.46
4
fi1� 4
r
rt 4
4
1
—StO-rt g-e 01.249 -af -
H 1-11
111-11
4
fi1rt�Irt1
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
783
782
m
m
0
> 781
m
w
780
779
Pond 2P: Sand Filter
Stage -Discharge
0
10 20 30
40 50
Discharge (cfs)
60
70
80
90
■ Inflow
■ Outflow
0 Primary
❑ Secondary
❑ Total
❑ Primary
❑ Secondary

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation (feet)
Pond 2P: Sand Filter
Stage -Area -Storage
Surface/Horizontal/Wetted Area (acres)
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09
Type 1124-hr 10-yr Rainfall=4.96"
Printed 5/19/2021
Page 47
0.1
0.11
0.12
783-'
782 '
781-
780-
779
II
II
II
I I II
I I I
I I I II
II I I I II
Ji
K K... ...K...K...K. .. K... ...K. .. ...K. .. .../
0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36
Storage (acre-feet)
Surface
❑ Storage

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Time Inflow
(hours) (cfs)
0.00 0.00
2.50 0.00
5.00 0.00
7.50 0.10
10.00 0.44
12.50 2.57
15.00 0.77
17.50 0.50
20.00 0.34
22.50 0.30
25.00 0.00
27.50 0.00
30.00 0.00
32.50 0.00
35.00 0.00
37.50 0.00
40.00 0.00
42.50 0.00
45.00 0.00
47.50 0.00
50.00 0.00
52.50 0.00
55.00 0.00
57.50 0.00
60.00 0.00
62.50 0.00
65.00 0.00
67.50 0.00
70.00 0.00
72.50 0.00
75.00 0.00
77.50 0.00
80.00 0.00
82.50 0.00
85.00 0.00
87.50 0.00
90.00 0.00
92.50 0.00
95.00 0.00
97.50 0.00
100.00 0.00
102.50 0.00
105.00 0.00
107.50 0.00
110.00 0.00
112.50 0.00
115.00 0.00
117.50 0.00
120.00 0.00
Hydrograph for Pond 2P: Sand Filter
Storage
(acre-feet)
0.000
0.000
0.000
0.008
0.052
0.094
0.088
0.087
0.086
0.086
0.081
0.072
0.062
0.054
0.046
0.039
0.033
0.028
0.023
0.019
0.016
0.014
0.011
0.009
0.008
0.007
0.005
0.005
0.004
0.003
0.003
0.002
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
Elevation
(feet)
779.00
779.00
779.00
779.16
780.00
780.64
780.56
780.54
780.53
780.53
780.45
780.31
780.16
780.02
779.88
779.76
779.65
779.56
779.48
779.40
779.34
779.29
779.24
779.20
779.17
779.14
779.12
779.10
779.08
779.07
779.06
779.05
779.04
779.03
779.03
779.02
779.02
779.02
779.01
779.01
779.01
779.01
779.01
779.01
779.00
779.00
779.00
779.00
779.00
Outflow
(cfs)
0.00
0.00
0.00
0.01
0.04
2.72
0.78
0.50
0.34
0.31
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Primary
(cfs)
0.00
0.00
0.00
0.01
0.04
2.72
0.78
0.50
0.34
0.31
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Type 1124-hr 10-yr Rainfall=4.96"
Printed 5/19/2021
Page 48

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation Discharge
(feet) (cfs)
779.00 0.00
779.05 0.00
779.10 0.00
779.15 0.01
779.20 0.01
779.25 0.01
779.30 0.01
779.35 0.01
779.40 0.02
779.45 0.02
779.50 0.02
779.55 0.02
779.60 0.02
779.65 0.03
779.70 0.03
779.75 0.03
779.80 0.03
779.85 0.03
779.90 0.04
779.95 0.04
780.00 0.04
780.05 0.04
780.10 0.04
780.15 0.04
780.20 0.04
780.25 0.04
780.30 0.05
780.35 0.05
780.40 0.05
780.45 0.05
780.50 0.05
780.55 0.63
780.60 1.71
780.65 3.09
780.70 4.73
780.75 6.59
780.80 8.65
780.85 10.89
780.90 13.29
780.95 13.49
781.00 13.57
781.05 13.65
781.10 13.74
781.15 13.82
781.20 13.90
781.25 13.98
781.30 14.06
781.35 14.15
781.40 14.23
781.45 14.30
781.50 14.38
781.55 14.46
781.60 14.54
Stage -Discharge for Pond 2P: Sand Filter
Primary
(cfs)
0.00
0.00
0.00
0.01
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.02
0.02
0.03
0.03
0.03
0.03
0.03
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.05
0.05
0.05
0.05
0.05
0.63
1.71
3.09
4.73
6.59
8.65
10.89
13.29
13.49
13.57
13.65
13.74
13.82
13.90
13.98
14.06
14.15
14.23
14.30
14.38
14.46
14.54
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Elevation Discharge
(feet) (cfs)
781.65 14.62
781.70 14.70
781.75 14.77
781.80 14.85
781.85 14.93
781.90 15.00
781.95 15.08
782.00 15.15
782.05 15.65
782.10 16.48
782.15 17.55
782.20 18.79
782.25 20.23
782.30 21.82
782.35 23.57
782.40 25.46
782.45 27.57
782.50 29.83
782.55 32.26
782.60 34.85
782.65 37.30
782.70 39.85
782.75 42.47
782.80 45.18
782.85 47.97
782.90 50.84
782.95 53.78
783.00 56.79
783.05 59.95
783.10 63.19
783.15 66.51
783.20 69.90
783.25 73.21
783.30 76.58
783.35 80.00
783.40 83.47
783.45 86.92
783.50 90.42
Primary
(cfs)
14.62
14.70
14.77
14.85
14.93
15.00
15.08
15.15
15.23
15.30
15.38
15.45
15.52
15.60
15.67
15.74
15.81
15.89
15.96
16.03
16.10
16.17
16.24
16.31
16.38
16.45
16.52
16.59
16.66
16.72
16.79
16.86
16.93
16.99
17.06
17.13
17.19
17.26
Type 1124-hr 10-yr Rainfall=4.96"
Printed 5/19/2021
Page 49
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.42
1.18
2.17
3.34
4.70
6.22
7.90
9.71
11.75
13.95
16.31
18.82
21.20
23.68
26.23
28.87
31.59
34.39
37.26
40.20
43.29
46.46
49.71
53.04
56.29
59.59
62.94
66.34
69.73
73.16

7544-Sand Filter Type 1124-hr 10-yr Rainfall=4.96"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 50
Stage -Area -Storage for Pond 2P: Sand Filter
Elevation Surface Storage Elevation Surface Storage
(feet) (acres) (acre-feet) (feet) (acres) (acre-feet)
779.00 0.045 0.000 781.65 0.087 0.173
779.05 0.046 0.002 781.70 0.088 0.177
779.10 0.047 0.005 781.75 0.088 0.181
779.15 0.047 0.007 781.80 0.089 0.186
779.20 0.048 0.009 781.85 0.090 0.190
779.25 0.049 0.012 781.90 0.091 0.195
779.30 0.049 0.014 781.95 0.092 0.199
779.35 0.050 0.017 782.00 0.093 0.204
779.40 0.051 0.019 782.05 0.094 0.209
779.45 0.052 0.022 782.10 0.095 0.213
779.50 0.052 0.024 782.15 0.096 0.218
779.55 0.053 0.027 782.20 0.097 0.223
779.60 0.054 0.030 782.25 0.098 0.228
779.65 0.055 0.032 782.30 0.098 0.233
779.70 0.056 0.035 782.35 0.099 0.238
779.75 0.056 0.038 782.40 0.100 0.243
779.80 0.057 0.041 782.45 0.101 0.248
779.85 0.058 0.044 782.50 0.102 0.253
779.90 0.058 0.047 782.55 0.103 0.258
779.95 0.059 0.050 782.60 0.104 0.263
780.00 0.060 0.052 782.65 0.105 0.268
780.05 0.061 0.056 782.70 0.106 0.274
780.10 0.062 0.059 782.75 0.106 0.279
780.15 0.062 0.062 782.80 0.107 0.284
780.20 0.063 0.065 782.85 0.108 0.290
780.25 0.064 0.068 782.90 0.109 0.295
780.30 0.064 0.071 782.95 0.110 0.300
780.35 0.065 0.074 783.00 0.111 0.306
780.40 0.066 0.078 783.05 0.112 0.312
780.45 0.067 0.081 783.10 0.113 0.317
780.50 0.068 0.084 783.15 0.114 0.323
780.55 0.068 0.088 783.20 0.115 0.329
780.60 0.069 0.091 783.25 0.116 0.334
780.65 0.070 0.095 783.30 0.117 0.340
780.70 0.071 0.098 783.35 0.118 0.346
780.75 0.071 0.102 783.40 0.119 0.352
780.80 0.072 0.105 783.45 0.120 0.358
780.85 0.073 0.109 783.50 0.121 0.364
780.90 0.073 0.113
780.95 0.074 0.116
781.00 0.075 0.120
781.05 0.076 0.124
781.10 0.077 0.128
781.15 0.078 0.131
781.20 0.079 0.135
781.25 0.079 0.139
781.30 0.080 0.143
781.35 0.081 0.147
781.40 0.082 0.151
781.45 0.083 0.156
781.50 0.084 0.160
781.55 0.085 0.164
781.60 0.086 0.168

7544-Sand Filter Type 1124-hr 25-yr Rainfall=5.90"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 51
Time span=0.00-120.00 hrs, dt=0.05 hrs, 2401 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1 S: Post-Dev 1 C Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=4.21"
Tc=5.0 min CN=85 Runoff=40.56 cfs 1.964 af
Subcatchment 12S: Water Quality Peak Flow Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=5.43"
Tc=5.0 min CN=96 Runoff=47.09 cfs 2.533 af
Pond 2P: Sand Filter Peak Elev=782.66' Storage=0.269 af Inflow=40.56 cfs 1.964 af
Primary=16.11 cfs 1.761 af Secondary=21.58 cfs 0.203 af Outflow=37.70 cfs 1.964 af
Total Runoff Area = 11.200 ac Runoff Volume = 4.497 af Average Runoff Depth = 4.82"
100.00% Pervious = 11.200 ac 0.00% Impervious = 0.000 ac

7544-Sand Filter Type 11 24-hr 25-yr Rainfall=5.90"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 52
Summary for Subcatchment 1 S: Post-Dev 1 C
[49] Hint: Tc<2dt may require smaller dt
Runoff = 40.56 cfs @ 11.95 hrs, Volume=
1.964 af, Depth= 4.21"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 25-yr Rainfall=5.90"
Area (ac) CN Description
5.600 85
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 1 S: Post-Dev 1 C
Hydrograph
42, 40.56 cfs
40—
38
36L— 1
V
34�
32�/ -
30 —
28i/2—
w 26�
-, 24-/
3 22�
LL 20�
18V -
16
14./ L
12�
10�
8/
1
6
2
—I1-I I4I-
1
— 1 4 RUUUnoff-AI-ea=5.600-ab -
�4pP�l V-914mIe7-1 •1164-0 -
1!rirl
�c.5.Q min
- -h 1-Ifi I I -h I -
1 1 I
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
• Runoff

7544-Sand Filter Type 1124-hr 25-yr Rainfall=5.90"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 53
Hydrograph for Subcatchment 1 S: Post-Dev 1 C
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.17 0.00 0.00
5.00 0.37 0.00 0.01
7.50 0.64 0.04 0.18
10.00 1.07 0.21 0.63
12.50 4.34 2.76 3.15
15.00 5.04 3.40 0.94
17.50 5.38 3.72 0.60
20.00 5.62 3.94 0.41
22.50 5.80 4.11 0.37
25.00 5.90 4.21 0.00
27.50 5.90 4.21 0.00
30.00 5.90 4.21 0.00
32.50 5.90 4.21 0.00
35.00 5.90 4.21 0.00
37.50 5.90 4.21 0.00
40.00 5.90 4.21 0.00
42.50 5.90 4.21 0.00
45.00 5.90 4.21 0.00
47.50 5.90 4.21 0.00
50.00 5.90 4.21 0.00
52.50 5.90 4.21 0.00
55.00 5.90 4.21 0.00
57.50 5.90 4.21 0.00
60.00 5.90 4.21 0.00
62.50 5.90 4.21 0.00
65.00 5.90 4.21 0.00
67.50 5.90 4.21 0.00
70.00 5.90 4.21 0.00
72.50 5.90 4.21 0.00
75.00 5.90 4.21 0.00
77.50 5.90 4.21 0.00
80.00 5.90 4.21 0.00
82.50 5.90 4.21 0.00
85.00 5.90 4.21 0.00
87.50 5.90 4.21 0.00
90.00 5.90 4.21 0.00
92.50 5.90 4.21 0.00
95.00 5.90 4.21 0.00
97.50 5.90 4.21 0.00
100.00 5.90 4.21 0.00
102.50 5.90 4.21 0.00
105.00 5.90 4.21 0.00
107.50 5.90 4.21 0.00
110.00 5.90 4.21 0.00
112.50 5.90 4.21 0.00
115.00 5.90 4.21 0.00
117.50 5.90 4.21 0.00
120.00 5.90 4.21 0.00

7544-Sand Filter Type 11 24-hr 25-yr Rainfall=5.90"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 54
Summary for Subcatchment 12S: Water Quality Peak Flow
[49] Hint: Tc<2dt may require smaller dt
Runoff
47.09 cfs @ 11.95 hrs, Volume= 2.533 af, Depth= 5.43"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 25-yr Rainfall=5.90"
Area (ac) CN Description
5.600 96
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0
Direct Entry,
Subcatchment 12S: Water Quality Peak Flow
Hydrograph
52
50iv
48�
4627
44
42-
40
38Y�
36�
34:
32�/
30
w
3, 28i'
26V0 24-
LL 22V
04/
6`
4.
2'
47.09 cf
- I 4 1- I -I + �� 113d-�hr =
I IBtlinoftAlrea i5.6 OO
- I R 9f-1 V1414 1e • f =
I 4 1- !Ii!rir1R/11.17'illii 1
c=5 9 mm
I I I �L�
I I II
- 141-1-1+ 41-1-1=
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
• Runoff

7544-Sand Filter Type 1124-hr 25-yr Rainfall=5.90"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 55
Hydrograph for Subcatchment 12S: Water Quality Peak Flow
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.17 0.01 0.12
5.00 0.37 0.12 0.34
7.50 0.64 0.32 0.57
10.00 1.07 0.69 1.17
12.50 4.34 3.87 3.46
15.00 5.04 4.57 1.01
17.50 5.38 4.91 0.64
20.00 5.62 5.15 0.44
22.50 5.80 5.33 0.39
25.00 5.90 5.43 0.00
27.50 5.90 5.43 0.00
30.00 5.90 5.43 0.00
32.50 5.90 5.43 0.00
35.00 5.90 5.43 0.00
37.50 5.90 5.43 0.00
40.00 5.90 5.43 0.00
42.50 5.90 5.43 0.00
45.00 5.90 5.43 0.00
47.50 5.90 5.43 0.00
50.00 5.90 5.43 0.00
52.50 5.90 5.43 0.00
55.00 5.90 5.43 0.00
57.50 5.90 5.43 0.00
60.00 5.90 5.43 0.00
62.50 5.90 5.43 0.00
65.00 5.90 5.43 0.00
67.50 5.90 5.43 0.00
70.00 5.90 5.43 0.00
72.50 5.90 5.43 0.00
75.00 5.90 5.43 0.00
77.50 5.90 5.43 0.00
80.00 5.90 5.43 0.00
82.50 5.90 5.43 0.00
85.00 5.90 5.43 0.00
87.50 5.90 5.43 0.00
90.00 5.90 5.43 0.00
92.50 5.90 5.43 0.00
95.00 5.90 5.43 0.00
97.50 5.90 5.43 0.00
100.00 5.90 5.43 0.00
102.50 5.90 5.43 0.00
105.00 5.90 5.43 0.00
107.50 5.90 5.43 0.00
110.00 5.90 5.43 0.00
112.50 5.90 5.43 0.00
115.00 5.90 5.43 0.00
117.50 5.90 5.43 0.00
120.00 5.90 5.43 0.00

7544-Sand Filter Type 1124-hr 25-yr Rainfall=5.90"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 56
Summary for Pond 2P: Sand Filter
Inflow Area = 5.600 ac, 0.00% Impervious, Inflow Depth = 4.21" for 25-yr event
Inflow = 40.56 cfs @ 11.95 hrs, Volume= 1.964 af
Outflow = 37.70 cfs @ 11.99 hrs, Volume= 1.964 af, Atten= 7%, Lag= 2.4 min
Primary = 16.11 cfs @ 11.99 hrs, Volume= 1.761 af
Secondary = 21.58 cfs @ 11.99 hrs, Volume= 0.203 af
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 782.66' @ 11.99 hrs Surf.Area= 0.105 ac Storage= 0.269 af
Plug -Flow detention time= 84.7 min calculated for 1.964 af (100% of inflow)
Center -of -Mass det. time= 84.5 min (881.7 - 797.2 )
Volume Invert Avail.Storage Storage Description
#1 779.00' 0.364 af Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
779.00 0.045 0.000 0.000
780.00 0.060 0.052 0.052
781.00 0.075 0.068 0.120
782.00 0.093 0.084 0.204
783.00 0.111 0.102 0.306
783.50 0.121 0.058 0.364
Device Routing Invert Outlet Devices
#1 Primary 776.50' 15.0" Round RCP_Round 15"
L= 40.0' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 776.50' / 775.70' S= 0.0200 '/' Cc= 0.900
n= 0.013, Flow Area= 1.23 sf
#2 Device 1 779.00' Special & User -Defined
Head (feet) 0.00 1.00 2.00 3.00 4.50
Disch. (cfs) 0.000 0.041 0.057 0.073 0.097
#3 Device 1 780.50' 48.0" x 48.0" Horiz. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Secondary 782.00' 15.0' long x 10.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Primary OutFlow Max=16.08 cfs @ 11.99 hrs HW=782.64' (Free Discharge)
4-1=RCP_Round 15" (Barrel Controls 16.08 cfs @ 13.10 fps)
12=Special & User -Defined (Passes < 0.08 cfs potential flow)
3=Orifice/Grate (Passes < 112.58 cfs potential flow)
Secondary OutFlow Max=20.57 cfs @ 11.99 hrs HW=782.64' (Free Discharge)
4=Emergency Spillway (Weir Controls 20.57 cfs @ 2.15 fps)

7544-Sand Filter Type 1124-hr 25-yr Rainfall=5.90"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 57
Pond 2P: Sand Filter
Hydrograph
/ / 40.56 cfs
l
44 = / 3�l7.70 cfs j
42 /
40V
38 /
36 / /
34/
32'
30/ / /
28/ /
y V 26 / 4
24 ! 21.58 cfs
22_
20
LL
18:
165
14'
12
10
8
6
4
2
0
H
tb 6Af4Ai.e% .6 o la- -
t
t
4
Riak ev*7a2.S6-
- StOrtie*A12691-af -
1 1 1
1 1 1
1—I I I— I I I I I-
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
783
782
m
m
0
> 781
m
w
780
779
Pond 2P: Sand Filter
Stage -Discharge
0
10 20 30
40 50
Discharge (cfs)
60
70
80
90
■ Inflow
• Outflow
0 Primary
❑ Secondary
❑ Total
❑ Primary
❑ Secondary

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation (feet)
Pond 2P: Sand Filter
Stage -Area -Storage
Surface/Horizontal/Wetted Area (acres)
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09
Type 1124-hr 25-yr Rainfall=5.90"
Printed 5/19/2021
Page 58
0.1
0.11
0.12
783-'
782 '
781-
780-
779
II
II
II
I I II
I I I
I I I II
II I I I II
Ji
K K... ...K...K...K. .. K... ...K. .. ...K. .. .../
0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36
Storage (acre-feet)
Surface
❑ Storage

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Time Inflow
(hours) (cfs)
0.00 0.00
2.50 0.00
5.00 0.01
7.50 0.18
10.00 0.63
12.50 3.15
15.00 0.94
17.50 0.60
20.00 0.41
22.50 0.37
25.00 0.00
27.50 0.00
30.00 0.00
32.50 0.00
35.00 0.00
37.50 0.00
40.00 0.00
42.50 0.00
45.00 0.00
47.50 0.00
50.00 0.00
52.50 0.00
55.00 0.00
57.50 0.00
60.00 0.00
62.50 0.00
65.00 0.00
67.50 0.00
70.00 0.00
72.50 0.00
75.00 0.00
77.50 0.00
80.00 0.00
82.50 0.00
85.00 0.00
87.50 0.00
90.00 0.00
92.50 0.00
95.00 0.00
97.50 0.00
100.00 0.00
102.50 0.00
105.00 0.00
107.50 0.00
110.00 0.00
112.50 0.00
115.00 0.00
117.50 0.00
120.00 0.00
Hydrograph for Pond 2P: Sand Filter
Storage
(acre-feet)
0.000
0.000
0.000
0.017
0.084
0.095
0.089
0.088
0.087
0.087
0.081
0.072
0.062
0.054
0.046
0.039
0.033
0.028
0.023
0.019
0.016
0.014
0.011
0.009
0.008
0.007
0.005
0.005
0.004
0.003
0.003
0.002
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
Elevation
(feet)
779.00
779.00
779.00
779.36
780.50
780.66
780.57
780.55
780.54
780.53
780.46
780.31
780.16
780.02
779.88
779.76
779.65
779.56
779.48
779.40
779.34
779.29
779.24
779.20
779.17
779.14
779.12
779.10
779.08
779.07
779.06
779.05
779.04
779.03
779.03
779.02
779.02
779.02
779.01
779.01
779.01
779.01
779.01
779.01
779.00
779.00
779.00
779.00
779.00
Outflow
(cfs)
0.00
0.00
0.00
0.01
0.05
3.34
0.95
0.61
0.42
0.37
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Primary
(cfs)
0.00
0.00
0.00
0.01
0.05
3.34
0.95
0.61
0.42
0.37
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Type 1124-hr 25-yr Rainfall=5.90"
Printed 5/19/2021
Page 59

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation Discharge
(feet) (cfs)
779.00 0.00
779.05 0.00
779.10 0.00
779.15 0.01
779.20 0.01
779.25 0.01
779.30 0.01
779.35 0.01
779.40 0.02
779.45 0.02
779.50 0.02
779.55 0.02
779.60 0.02
779.65 0.03
779.70 0.03
779.75 0.03
779.80 0.03
779.85 0.03
779.90 0.04
779.95 0.04
780.00 0.04
780.05 0.04
780.10 0.04
780.15 0.04
780.20 0.04
780.25 0.04
780.30 0.05
780.35 0.05
780.40 0.05
780.45 0.05
780.50 0.05
780.55 0.63
780.60 1.71
780.65 3.09
780.70 4.73
780.75 6.59
780.80 8.65
780.85 10.89
780.90 13.29
780.95 13.49
781.00 13.57
781.05 13.65
781.10 13.74
781.15 13.82
781.20 13.90
781.25 13.98
781.30 14.06
781.35 14.15
781.40 14.23
781.45 14.30
781.50 14.38
781.55 14.46
781.60 14.54
Stage -Discharge for Pond 2P: Sand Filter
Primary
(cfs)
0.00
0.00
0.00
0.01
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.02
0.02
0.03
0.03
0.03
0.03
0.03
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.05
0.05
0.05
0.05
0.05
0.63
1.71
3.09
4.73
6.59
8.65
10.89
13.29
13.49
13.57
13.65
13.74
13.82
13.90
13.98
14.06
14.15
14.23
14.30
14.38
14.46
14.54
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Elevation Discharge
(feet) (cfs)
781.65 14.62
781.70 14.70
781.75 14.77
781.80 14.85
781.85 14.93
781.90 15.00
781.95 15.08
782.00 15.15
782.05 15.65
782.10 16.48
782.15 17.55
782.20 18.79
782.25 20.23
782.30 21.82
782.35 23.57
782.40 25.46
782.45 27.57
782.50 29.83
782.55 32.26
782.60 34.85
782.65 37.30
782.70 39.85
782.75 42.47
782.80 45.18
782.85 47.97
782.90 50.84
782.95 53.78
783.00 56.79
783.05 59.95
783.10 63.19
783.15 66.51
783.20 69.90
783.25 73.21
783.30 76.58
783.35 80.00
783.40 83.47
783.45 86.92
783.50 90.42
Primary
(cfs)
14.62
14.70
14.77
14.85
14.93
15.00
15.08
15.15
15.23
15.30
15.38
15.45
15.52
15.60
15.67
15.74
15.81
15.89
15.96
16.03
16.10
16.17
16.24
16.31
16.38
16.45
16.52
16.59
16.66
16.72
16.79
16.86
16.93
16.99
17.06
17.13
17.19
17.26
Type 1124-hr 25-yr Rainfall=5.90"
Printed 5/19/2021
Page 60
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.42
1.18
2.17
3.34
4.70
6.22
7.90
9.71
11.75
13.95
16.31
18.82
21.20
23.68
26.23
28.87
31.59
34.39
37.26
40.20
43.29
46.46
49.71
53.04
56.29
59.59
62.94
66.34
69.73
73.16

7544-Sand Filter Type 1124-hr 25-yr Rainfall=5.90"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 61
Stage -Area -Storage for Pond 2P: Sand Filter
Elevation Surface Storage Elevation Surface Storage
(feet) (acres) (acre-feet) (feet) (acres) (acre-feet)
779.00 0.045 0.000 781.65 0.087 0.173
779.05 0.046 0.002 781.70 0.088 0.177
779.10 0.047 0.005 781.75 0.088 0.181
779.15 0.047 0.007 781.80 0.089 0.186
779.20 0.048 0.009 781.85 0.090 0.190
779.25 0.049 0.012 781.90 0.091 0.195
779.30 0.049 0.014 781.95 0.092 0.199
779.35 0.050 0.017 782.00 0.093 0.204
779.40 0.051 0.019 782.05 0.094 0.209
779.45 0.052 0.022 782.10 0.095 0.213
779.50 0.052 0.024 782.15 0.096 0.218
779.55 0.053 0.027 782.20 0.097 0.223
779.60 0.054 0.030 782.25 0.098 0.228
779.65 0.055 0.032 782.30 0.098 0.233
779.70 0.056 0.035 782.35 0.099 0.238
779.75 0.056 0.038 782.40 0.100 0.243
779.80 0.057 0.041 782.45 0.101 0.248
779.85 0.058 0.044 782.50 0.102 0.253
779.90 0.058 0.047 782.55 0.103 0.258
779.95 0.059 0.050 782.60 0.104 0.263
780.00 0.060 0.052 782.65 0.105 0.268
780.05 0.061 0.056 782.70 0.106 0.274
780.10 0.062 0.059 782.75 0.106 0.279
780.15 0.062 0.062 782.80 0.107 0.284
780.20 0.063 0.065 782.85 0.108 0.290
780.25 0.064 0.068 782.90 0.109 0.295
780.30 0.064 0.071 782.95 0.110 0.300
780.35 0.065 0.074 783.00 0.111 0.306
780.40 0.066 0.078 783.05 0.112 0.312
780.45 0.067 0.081 783.10 0.113 0.317
780.50 0.068 0.084 783.15 0.114 0.323
780.55 0.068 0.088 783.20 0.115 0.329
780.60 0.069 0.091 783.25 0.116 0.334
780.65 0.070 0.095 783.30 0.117 0.340
780.70 0.071 0.098 783.35 0.118 0.346
780.75 0.071 0.102 783.40 0.119 0.352
780.80 0.072 0.105 783.45 0.120 0.358
780.85 0.073 0.109 783.50 0.121 0.364
780.90 0.073 0.113
780.95 0.074 0.116
781.00 0.075 0.120
781.05 0.076 0.124
781.10 0.077 0.128
781.15 0.078 0.131
781.20 0.079 0.135
781.25 0.079 0.139
781.30 0.080 0.143
781.35 0.081 0.147
781.40 0.082 0.151
781.45 0.083 0.156
781.50 0.084 0.160
781.55 0.085 0.164
781.60 0.086 0.168

7544-Sand Filter Type 11 24-hr 50-yr Rainfall=6.65"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 62
Time span=0.00-120.00 hrs, dt=0.05 hrs, 2401 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1 S: Post-Dev 1 C Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=4.92"
Tc=5.0 min CN=85 Runoff=46.96 cfs 2.295 af
Subcatchment 12S: Water Quality Peak Flow Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=6.17"
Tc=5.0 min CN=96 Runoff=53.23 cfs 2.882 af
Pond 2P: Sand Filter Peak Elev=782.79' Storage=0.283 af Inflow=46.96 cfs 2.295 af
Primary=16.29 cfs 1.983 af Secondary=28.15 cfs 0.312 af Outflow=44.45 cfs 2.295 af
Total Runoff Area = 11.200 ac Runoff Volume = 5.177 af Average Runoff Depth = 5.55"
100.00% Pervious = 11.200 ac 0.00% Impervious = 0.000 ac

444f/6� 1
42 1
40
381/ L
36
34
32
w 30
28-
3 26 L
0 24
22/
20/I
18:
16�
1412
12:
10�
8'
6°
4
2-
7544-Sand Filter Type 11 24-hr 50-yr Rainfall=6.65"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 63
Summary for Subcatchment 1 S: Post-Dev 1 C
[49] Hint: Tc<2dt may require smaller dt
Runoff = 46.96 cfs @ 11.95 hrs, Volume=
2.295 af, Depth= 4.92"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 50-yr Rainfall=6.65"
Area (ac) CN Description
5.600 85
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0
Direct Entry,
Subcatchment 1 S: Post-Dev 1 C
Hydrograph
52/ I
50/1 46.96 cfs
48'1
L
I-1 -H
H I 113d-�hr =
- 1 4y1Ra'r�fll6.1Cs5�"
I Rtli _ ftAlrea i5.6 OO
— I R 9fl V414 1e •PW =
— I 4 I— !11;!rir14!1:TI-" 1
II
- I 1—IH+1 14=
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
• Runoff

7544-Sand Filter Type 11 24-hr 50-yr Rainfall=6.65"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 64
Hydrograph for Subcatchment 1 S: Post-Dev 1 C
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.19 0.00 0.00
5.00 0.42 0.00 0.04
7.50 0.73 0.07 0.24
10.00 1.20 0.28 0.78
12.50 4.89 3.26 3.61
15.00 5.68 4.00 1.08
17.50 6.06 4.36 0.69
20.00 6.33 4.62 0.47
22.50 6.54 4.81 0.42
25.00 6.65 4.92 0.00
27.50 6.65 4.92 0.00
30.00 6.65 4.92 0.00
32.50 6.65 4.92 0.00
35.00 6.65 4.92 0.00
37.50 6.65 4.92 0.00
40.00 6.65 4.92 0.00
42.50 6.65 4.92 0.00
45.00 6.65 4.92 0.00
47.50 6.65 4.92 0.00
50.00 6.65 4.92 0.00
52.50 6.65 4.92 0.00
55.00 6.65 4.92 0.00
57.50 6.65 4.92 0.00
60.00 6.65 4.92 0.00
62.50 6.65 4.92 0.00
65.00 6.65 4.92 0.00
67.50 6.65 4.92 0.00
70.00 6.65 4.92 0.00
72.50 6.65 4.92 0.00
75.00 6.65 4.92 0.00
77.50 6.65 4.92 0.00
80.00 6.65 4.92 0.00
82.50 6.65 4.92 0.00
85.00 6.65 4.92 0.00
87.50 6.65 4.92 0.00
90.00 6.65 4.92 0.00
92.50 6.65 4.92 0.00
95.00 6.65 4.92 0.00
97.50 6.65 4.92 0.00
100.00 6.65 4.92 0.00
102.50 6.65 4.92 0.00
105.00 6.65 4.92 0.00
107.50 6.65 4.92 0.00
110.00 6.65 4.92 0.00
112.50 6.65 4.92 0.00
115.00 6.65 4.92 0.00
117.50 6.65 4.92 0.00
120.00 6.65 4.92 0.00

7544-Sand Filter Type 11 24-hr 50-yr Rainfall=6.65"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 65
Summary for Subcatchment 12S: Water Quality Peak Flow
[49] Hint: Tc<2dt may require smaller dt
Runoff = 53.23 cfs @ 11.95 hrs, Volume= 2.882 af, Depth= 6.17"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 50-yr Rainfall=6.65"
Area (ac) CN Description
5.600 96
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0
55
50
45
40
35
3 30
LL 25
20
15
10
5
0
Direct Entry,
Subcatchment 12S: Water Quality Peak Flow
Hydrograph
53.23 cfs
I� I
I
Typ
� 9-I-y1-Rainf11 6.165"
tR in- ff-4rea=5.6A4 a-d
Rtirn9ffi V-pIume2.:-
!R-uncitffIDeph76.1t-7"
Tc=5 $ min
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
• Runoff

7544-Sand Filter Type 11 24-hr 50-yr Rainfall=6.65"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 66
Hydrograph for Subcatchment 12S: Water Quality Peak Flow
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.19 0.02 0.16
5.00 0.42 0.15 0.41
7.50 0.73 0.39 0.66
10.00 1.20 0.82 1.35
12.50 4.89 4.42 3.90
15.00 5.68 5.20 1.14
17.50 6.06 5.59 0.73
20.00 6.33 5.86 0.49
22.50 6.54 6.06 0.44
25.00 6.65 6.17 0.00
27.50 6.65 6.17 0.00
30.00 6.65 6.17 0.00
32.50 6.65 6.17 0.00
35.00 6.65 6.17 0.00
37.50 6.65 6.17 0.00
40.00 6.65 6.17 0.00
42.50 6.65 6.17 0.00
45.00 6.65 6.17 0.00
47.50 6.65 6.17 0.00
50.00 6.65 6.17 0.00
52.50 6.65 6.17 0.00
55.00 6.65 6.17 0.00
57.50 6.65 6.17 0.00
60.00 6.65 6.17 0.00
62.50 6.65 6.17 0.00
65.00 6.65 6.17 0.00
67.50 6.65 6.17 0.00
70.00 6.65 6.17 0.00
72.50 6.65 6.17 0.00
75.00 6.65 6.17 0.00
77.50 6.65 6.17 0.00
80.00 6.65 6.17 0.00
82.50 6.65 6.17 0.00
85.00 6.65 6.17 0.00
87.50 6.65 6.17 0.00
90.00 6.65 6.17 0.00
92.50 6.65 6.17 0.00
95.00 6.65 6.17 0.00
97.50 6.65 6.17 0.00
100.00 6.65 6.17 0.00
102.50 6.65 6.17 0.00
105.00 6.65 6.17 0.00
107.50 6.65 6.17 0.00
110.00 6.65 6.17 0.00
112.50 6.65 6.17 0.00
115.00 6.65 6.17 0.00
117.50 6.65 6.17 0.00
120.00 6.65 6.17 0.00

7544-Sand Filter Type 11 24-hr 50-yr Rainfall=6.65"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 67
Summary for Pond 2P: Sand Filter
Inflow Area = 5.600 ac, 0.00% Impervious, Inflow Depth = 4.92" for 50-yr event
Inflow = 46.96 cfs @ 11.95 hrs, Volume= 2.295 af
Outflow = 44.45 cfs @ 11.98 hrs, Volume= 2.295 af, Atten= 5%, Lag= 1.7 min
Primary = 16.29 cfs @ 11.98 hrs, Volume= 1.983 af
Secondary = 28.15 cfs @ 11.98 hrs, Volume= 0.312 af
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 782.79' @ 11.98 hrs Surf.Area= 0.107 ac Storage= 0.283 af
Plug -Flow detention time= 72.2 min calculated for 2.294 af (100% of inflow)
Center -of -Mass det. time= 74.0 min (866.8 - 792.8 )
Volume Invert Avail.Storage Storage Description
#1 779.00' 0.364 af Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
779.00 0.045 0.000 0.000
780.00 0.060 0.052 0.052
781.00 0.075 0.068 0.120
782.00 0.093 0.084 0.204
783.00 0.111 0.102 0.306
783.50 0.121 0.058 0.364
Device Routing Invert Outlet Devices
#1 Primary 776.50' 15.0" Round RCP_Round 15"
L= 40.0' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 776.50' / 775.70' S= 0.0200 '/' Cc= 0.900
n= 0.013, Flow Area= 1.23 sf
#2 Device 1 779.00' Special & User -Defined
Head (feet) 0.00 1.00 2.00 3.00 4.50
Disch. (cfs) 0.000 0.041 0.057 0.073 0.097
#3 Device 1 780.50' 48.0" x 48.0" Horiz. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Secondary 782.00' 15.0' long x 10.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Primary OutFlow Max=16.25 cfs @ 11.98 hrs HW=782.75' (Free Discharge)
4-1=RCP_Round 15" (Barrel Controls 16.25 cfs @ 13.24 fps)
12=Special & User -Defined (Passes < 0.09 cfs potential flow)
3=Orifice/Grate (Passes < 115.67 cfs potential flow)
Secondary OutFlow Max=26.47 cfs @ 11.98 hrs HW=782.75' (Free Discharge)
4=Emergency Spillway (Weir Controls 26.47 cfs @ 2.34 fps)

7544-Sand Filter Type 11 24-hr 50-yr Rainfall=6.65"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 68
Pond 2P: Sand Filter
Hydrograph
46.96 cfs
L44.45 cfs
50- / / (%
45/ /
40- /
35Y /
301/I 28.15 cfs
c 25- /
LL 20� 16
15-
10-
5-
cfs
7
7
r
7
Inflow Are�a.600 ac
Peak Elev=782.79'
Storage=l 0.283 of
L
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
783
782
m
0
> 781
m
w
780
779
0
10
Pond 2P: Sand Filter
Stage -Discharge
40 50
Discharge (cfs)
60
70
80
90
❑ Inflow
❑ Outflow
❑ Primary
❑ Secondary
❑ Total
❑ Primary
❑ Secondary

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation (feet)
Pond 2P: Sand Filter
Stage -Area -Storage
Surface/Horizontal/Wetted Area (acres)
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09
Type 11 24-hr 50-yr Rainfall=6.65"
Printed 5/19/2021
Page 69
0.1
0.11
0.12
783-'
782 '
781-
780-
779
II
II
II
I I II
I I I
I I I II
II I I I II
Ji
K K... ...K...K...K. .. K... ...K. .. ...K. .. .../
0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36
Storage (acre-feet)
Surface
❑ Storage

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Time Inflow
(hours) (cfs)
0.00 0.00
2.50 0.00
5.00 0.04
7.50 0.24
10.00 0.78
12.50 3.61
15.00 1.08
17.50 0.69
20.00 0.47
22.50 0.42
25.00 0.00
27.50 0.00
30.00 0.00
32.50 0.00
35.00 0.00
37.50 0.00
40.00 0.00
42.50 0.00
45.00 0.00
47.50 0.00
50.00 0.00
52.50 0.00
55.00 0.00
57.50 0.00
60.00 0.00
62.50 0.00
65.00 0.00
67.50 0.00
70.00 0.00
72.50 0.00
75.00 0.00
77.50 0.00
80.00 0.00
82.50 0.00
85.00 0.00
87.50 0.00
90.00 0.00
92.50 0.00
95.00 0.00
97.50 0.00
100.00 0.00
102.50 0.00
105.00 0.00
107.50 0.00
110.00 0.00
112.50 0.00
115.00 0.00
117.50 0.00
120.00 0.00
Hydrograph for Pond 2P: Sand Filter
Storage
(acre-feet)
0.000
0.000
0.001
0.027
0.088
0.096
0.089
0.088
0.087
0.087
0.081
0.072
0.062
0.054
0.046
0.039
0.033
0.028
0.023
0.019
0.016
0.014
0.011
0.009
0.008
0.007
0.005
0.005
0.004
0.003
0.003
0.002
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
Elevation
(feet)
779.00
779.00
779.02
779.55
780.55
780.67
780.57
780.55
780.54
780.54
780.46
780.31
780.16
780.02
779.88
779.76
779.65
779.56
779.48
779.40
779.34
779.29
779.24
779.20
779.17
779.14
779.12
779.10
779.08
779.07
779.06
779.05
779.04
779.03
779.03
779.02
779.02
779.02
779.01
779.01
779.01
779.01
779.01
779.01
779.00
779.00
779.00
779.00
779.00
Outflow
(cfs)
0.00
0.00
0.00
0.02
0.76
3.81
1.09
0.69
0.47
0.42
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Primary
(cfs)
0.00
0.00
0.00
0.02
0.76
3.81
1.09
0.69
0.47
0.42
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Type 11 24-hr 50-yr Rainfall=6.65"
Printed 5/19/2021
Page 70

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation Discharge
(feet) (cfs)
779.00 0.00
779.05 0.00
779.10 0.00
779.15 0.01
779.20 0.01
779.25 0.01
779.30 0.01
779.35 0.01
779.40 0.02
779.45 0.02
779.50 0.02
779.55 0.02
779.60 0.02
779.65 0.03
779.70 0.03
779.75 0.03
779.80 0.03
779.85 0.03
779.90 0.04
779.95 0.04
780.00 0.04
780.05 0.04
780.10 0.04
780.15 0.04
780.20 0.04
780.25 0.04
780.30 0.05
780.35 0.05
780.40 0.05
780.45 0.05
780.50 0.05
780.55 0.63
780.60 1.71
780.65 3.09
780.70 4.73
780.75 6.59
780.80 8.65
780.85 10.89
780.90 13.29
780.95 13.49
781.00 13.57
781.05 13.65
781.10 13.74
781.15 13.82
781.20 13.90
781.25 13.98
781.30 14.06
781.35 14.15
781.40 14.23
781.45 14.30
781.50 14.38
781.55 14.46
781.60 14.54
Stage -Discharge for Pond 2P: Sand Filter
Primary
(cfs)
0.00
0.00
0.00
0.01
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.02
0.02
0.03
0.03
0.03
0.03
0.03
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.05
0.05
0.05
0.05
0.05
0.63
1.71
3.09
4.73
6.59
8.65
10.89
13.29
13.49
13.57
13.65
13.74
13.82
13.90
13.98
14.06
14.15
14.23
14.30
14.38
14.46
14.54
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Elevation Discharge
(feet) (cfs)
781.65 14.62
781.70 14.70
781.75 14.77
781.80 14.85
781.85 14.93
781.90 15.00
781.95 15.08
782.00 15.15
782.05 15.65
782.10 16.48
782.15 17.55
782.20 18.79
782.25 20.23
782.30 21.82
782.35 23.57
782.40 25.46
782.45 27.57
782.50 29.83
782.55 32.26
782.60 34.85
782.65 37.30
782.70 39.85
782.75 42.47
782.80 45.18
782.85 47.97
782.90 50.84
782.95 53.78
783.00 56.79
783.05 59.95
783.10 63.19
783.15 66.51
783.20 69.90
783.25 73.21
783.30 76.58
783.35 80.00
783.40 83.47
783.45 86.92
783.50 90.42
Primary
(cfs)
14.62
14.70
14.77
14.85
14.93
15.00
15.08
15.15
15.23
15.30
15.38
15.45
15.52
15.60
15.67
15.74
15.81
15.89
15.96
16.03
16.10
16.17
16.24
16.31
16.38
16.45
16.52
16.59
16.66
16.72
16.79
16.86
16.93
16.99
17.06
17.13
17.19
17.26
Type 11 24-hr 50-yr Rainfall=6.65"
Printed 5/19/2021
Page 71
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.42
1.18
2.17
3.34
4.70
6.22
7.90
9.71
11.75
13.95
16.31
18.82
21.20
23.68
26.23
28.87
31.59
34.39
37.26
40.20
43.29
46.46
49.71
53.04
56.29
59.59
62.94
66.34
69.73
73.16

7544-Sand Filter Type 11 24-hr 50-yr Rainfall=6.65"
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 72
Stage -Area -Storage for Pond 2P: Sand Filter
Elevation Surface Storage Elevation Surface Storage
(feet) (acres) (acre-feet) (feet) (acres) (acre-feet)
779.00 0.045 0.000 781.65 0.087 0.173
779.05 0.046 0.002 781.70 0.088 0.177
779.10 0.047 0.005 781.75 0.088 0.181
779.15 0.047 0.007 781.80 0.089 0.186
779.20 0.048 0.009 781.85 0.090 0.190
779.25 0.049 0.012 781.90 0.091 0.195
779.30 0.049 0.014 781.95 0.092 0.199
779.35 0.050 0.017 782.00 0.093 0.204
779.40 0.051 0.019 782.05 0.094 0.209
779.45 0.052 0.022 782.10 0.095 0.213
779.50 0.052 0.024 782.15 0.096 0.218
779.55 0.053 0.027 782.20 0.097 0.223
779.60 0.054 0.030 782.25 0.098 0.228
779.65 0.055 0.032 782.30 0.098 0.233
779.70 0.056 0.035 782.35 0.099 0.238
779.75 0.056 0.038 782.40 0.100 0.243
779.80 0.057 0.041 782.45 0.101 0.248
779.85 0.058 0.044 782.50 0.102 0.253
779.90 0.058 0.047 782.55 0.103 0.258
779.95 0.059 0.050 782.60 0.104 0.263
780.00 0.060 0.052 782.65 0.105 0.268
780.05 0.061 0.056 782.70 0.106 0.274
780.10 0.062 0.059 782.75 0.106 0.279
780.15 0.062 0.062 782.80 0.107 0.284
780.20 0.063 0.065 782.85 0.108 0.290
780.25 0.064 0.068 782.90 0.109 0.295
780.30 0.064 0.071 782.95 0.110 0.300
780.35 0.065 0.074 783.00 0.111 0.306
780.40 0.066 0.078 783.05 0.112 0.312
780.45 0.067 0.081 783.10 0.113 0.317
780.50 0.068 0.084 783.15 0.114 0.323
780.55 0.068 0.088 783.20 0.115 0.329
780.60 0.069 0.091 783.25 0.116 0.334
780.65 0.070 0.095 783.30 0.117 0.340
780.70 0.071 0.098 783.35 0.118 0.346
780.75 0.071 0.102 783.40 0.119 0.352
780.80 0.072 0.105 783.45 0.120 0.358
780.85 0.073 0.109 783.50 0.121 0.364
780.90 0.073 0.113
780.95 0.074 0.116
781.00 0.075 0.120
781.05 0.076 0.124
781.10 0.077 0.128
781.15 0.078 0.131
781.20 0.079 0.135
781.25 0.079 0.139
781.30 0.080 0.143
781.35 0.081 0.147
781.40 0.082 0.151
781.45 0.083 0.156
781.50 0.084 0.160
781.55 0.085 0.164
781.60 0.086 0.168

7544-Sand Filter Type 11 24-hr 100-yr Rainfall=7.41 "
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 73
Time span=0.00-120.00 hrs, dt=0.05 hrs, 2401 points
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN
Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method
Subcatchment 1 S: Post-Dev 1 C Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=5.65"
Tc=5.0 min CN=85 Runoff=53.44 cfs 2.635 af
Subcatchment 12S: Water Quality Peak Flow Runoff Area=5.600 ac 0.00% Impervious Runoff Depth=6.93"
Tc=5.0 min CN=96 Runoff=59.44 cfs 3.235 af
Pond 2P: Sand Filter Peak Elev=782.90' Storage=0.296 af Inflow=53.44 cfs 2.635 af
Primary=16.46 cfs 2.205 af Secondary=34.50 cfs 0.430 af Outflow=50.95 cfs 2.634 af
Total Runoff Area = 11.200 ac Runoff Volume = 5.870 af Average Runoff Depth = 6.29"
100.00% Pervious = 11.200 ac 0.00% Impervious = 0.000 ac

7544-Sand Filter Type 11 24-hr 100-yr Rainfall=7.41 "
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 74
Summary for Subcatchment 1 S: Post-Dev 1 C
[49] Hint: Tc<2dt may require smaller dt
Runoff = 53.44 cfs @ 11.95 hrs, Volume=
2.635 af, Depth= 5.65"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 100-yr Rainfall=7.41"
Area (ac) CN Description
5.600 85
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0
55
50
45
40
35
30
_o
LL 25
20
15
10
5
0
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
Direct Entry,
Subcatchment 1 S: Post-Dev 1 C
Hydrograph
53.44 cfs
/
- — — I I-24-h r -
�1 byRat�fll.�41�" -
-h fRilinoff-Area=5.600 -ad -
-R nipffi V-Qlume7-2.p f
nciiff IDeph-5.I65" -
Tc=5-a m m -
■ Runoff

7544-Sand Filter Type 11 24-hr 100-yr Rainfall=7.41 "
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 75
Hydrograph for Subcatchment 1 S: Post-Dev 1 C
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.21 0.00 0.00
5.00 0.47 0.01 0.07
7.50 0.81 0.09 0.32
10.00 1.34 0.35 0.94
12.50 5.45 3.78 4.08
15.00 6.32 4.61 1.21
17.50 6.76 5.02 0.78
20.00 7.05 5.30 0.53
22.50 7.28 5.52 0.47
25.00 7.41 5.65 0.00
27.50 7.41 5.65 0.00
30.00 7.41 5.65 0.00
32.50 7.41 5.65 0.00
35.00 7.41 5.65 0.00
37.50 7.41 5.65 0.00
40.00 7.41 5.65 0.00
42.50 7.41 5.65 0.00
45.00 7.41 5.65 0.00
47.50 7.41 5.65 0.00
50.00 7.41 5.65 0.00
52.50 7.41 5.65 0.00
55.00 7.41 5.65 0.00
57.50 7.41 5.65 0.00
60.00 7.41 5.65 0.00
62.50 7.41 5.65 0.00
65.00 7.41 5.65 0.00
67.50 7.41 5.65 0.00
70.00 7.41 5.65 0.00
72.50 7.41 5.65 0.00
75.00 7.41 5.65 0.00
77.50 7.41 5.65 0.00
80.00 7.41 5.65 0.00
82.50 7.41 5.65 0.00
85.00 7.41 5.65 0.00
87.50 7.41 5.65 0.00
90.00 7.41 5.65 0.00
92.50 7.41 5.65 0.00
95.00 7.41 5.65 0.00
97.50 7.41 5.65 0.00
100.00 7.41 5.65 0.00
102.50 7.41 5.65 0.00
105.00 7.41 5.65 0.00
107.50 7.41 5.65 0.00
110.00 7.41 5.65 0.00
112.50 7.41 5.65 0.00
115.00 7.41 5.65 0.00
117.50 7.41 5.65 0.00
120.00 7.41 5.65 0.00

7544-Sand Filter Type 11 24-hr 100-yr Rainfall=7.41 "
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 76
Summary for Subcatchment 12S: Water Quality Peak Flow
[49] Hint: Tc<2dt may require smaller dt
Runoff = 59.44 cfs @ 11.95 hrs, Volume= 3.235 af, Depth= 6.93"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Type II 24-hr 100-yr Rainfall=7.41"
Area (ac) CN Description
5.600 96
5.600 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry,
Subcatchment 12S: Water Quality Peak Flow
Hydrograph
65
607
55-/
507/
457/
40-
357/
LL 30-/
257/
20-
15/
107r
5/I
59.44 cfs
1H
1 1 1 1 �ipa �r2d-w1r -
1 �1 b9�yRet�fll�41�"
fi tRtIm bff-AIea=5.6OQ -
j 1 -11Rt1n9ff V-ffnle73•PW
!Rnr11::ifp_h=.p3"
Tc=5 0
min
n
-1 1- 1-I-1 1-1 Irt6-NL
I I I I
1 1 I
1 1 I
Il
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
• Runoff

7544-Sand Filter Type 11 24-hr 100-yr Rainfall=7.41 "
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 77
Hydrograph for Subcatchment 12S: Water Quality Peak Flow
Time Precip. Excess Runoff
(hours) (inches) (inches) (cfs)
0.00 0.00 0.00 0.00
2.50 0.21 0.03 0.20
5.00 0.47 0.18 0.48
7.50 0.81 0.46 0.75
10.00 1.34 0.94 1.52
12.50 5.45 4.98 4.35
15.00 6.32 5.85 1.27
17.50 6.76 6.28 0.81
20.00 7.05 6.58 0.55
22.50 7.28 6.81 0.49
25.00 7.41 6.93 0.00
27.50 7.41 6.93 0.00
30.00 7.41 6.93 0.00
32.50 7.41 6.93 0.00
35.00 7.41 6.93 0.00
37.50 7.41 6.93 0.00
40.00 7.41 6.93 0.00
42.50 7.41 6.93 0.00
45.00 7.41 6.93 0.00
47.50 7.41 6.93 0.00
50.00 7.41 6.93 0.00
52.50 7.41 6.93 0.00
55.00 7.41 6.93 0.00
57.50 7.41 6.93 0.00
60.00 7.41 6.93 0.00
62.50 7.41 6.93 0.00
65.00 7.41 6.93 0.00
67.50 7.41 6.93 0.00
70.00 7.41 6.93 0.00
72.50 7.41 6.93 0.00
75.00 7.41 6.93 0.00
77.50 7.41 6.93 0.00
80.00 7.41 6.93 0.00
82.50 7.41 6.93 0.00
85.00 7.41 6.93 0.00
87.50 7.41 6.93 0.00
90.00 7.41 6.93 0.00
92.50 7.41 6.93 0.00
95.00 7.41 6.93 0.00
97.50 7.41 6.93 0.00
100.00 7.41 6.93 0.00
102.50 7.41 6.93 0.00
105.00 7.41 6.93 0.00
107.50 7.41 6.93 0.00
110.00 7.41 6.93 0.00
112.50 7.41 6.93 0.00
115.00 7.41 6.93 0.00
117.50 7.41 6.93 0.00
120.00 7.41 6.93 0.00

7544-Sand Filter Type 11 24-hr 100-yr Rainfall=7.41 "
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 78
Summary for Pond 2P: Sand Filter
Inflow Area = 5.600 ac, 0.00% Impervious, Inflow Depth = 5.65" for 100-yr event
Inflow = 53.44 cfs @ 11.95 hrs, Volume= 2.635 af
Outflow = 50.95 cfs @ 11.98 hrs, Volume= 2.634 af, Atten= 5%, Lag= 1.5 min
Primary = 16.46 cfs @ 11.98 hrs, Volume= 2.205 af
Secondary = 34.50 cfs @ 11.98 hrs, Volume= 0.430 af
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.05 hrs
Peak Elev= 782.90' @ 11.98 hrs Surf.Area= 0.109 ac Storage= 0.296 af
Plug -Flow detention time= 64.1 min calculated for 2.633 af (100% of inflow)
Center -of -Mass det. time= 65.9 min (854.8 - 789.0 )
Volume Invert Avail.Storage Storage Description
#1 779.00' 0.364 af Custom Stage Data (Prismatic)Listed below (Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (acres) (acre-feet) (acre-feet)
779.00 0.045 0.000 0.000
780.00 0.060 0.052 0.052
781.00 0.075 0.068 0.120
782.00 0.093 0.084 0.204
783.00 0.111 0.102 0.306
783.50 0.121 0.058 0.364
Device Routing Invert Outlet Devices
#1 Primary 776.50' 15.0" Round RCP_Round 15"
L= 40.0' RCP, groove end projecting, Ke= 0.200
Inlet / Outlet Invert= 776.50' / 775.70' S= 0.0200 '/' Cc= 0.900
n= 0.013, Flow Area= 1.23 sf
#2 Device 1 779.00' Special & User -Defined
Head (feet) 0.00 1.00 2.00 3.00 4.50
Disch. (cfs) 0.000 0.041 0.057 0.073 0.097
#3 Device 1 780.50' 48.0" x 48.0" Horiz. Orifice/Grate C= 0.600
Limited to weir flow at low heads
#4 Secondary 782.00' 15.0' long x 10.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Coef. (English) 2.49 2.56 2.70 2.69 2.68 2.69 2.67 2.64
Primary OutFlow Max=16.41 cfs @ 11.98 hrs HW=782.87' (Free Discharge)
4-1=RCP_Round 15" (Barrel Controls 16.41 cfs @ 13.37 fps)
12=Special & User -Defined (Passes < 0.09 cfs potential flow)
3=Orifice/Grate (Passes < 118.57 cfs potential flow)
Secondary OutFlow Max=32.63 cfs @ 11.98 hrs HW=782.87' (Free Discharge)
4=Emergency Spillway (Weir Controls 32.63 cfs @ 2.50 fps)

7544-Sand Filter Type 11 24-hr 100-yr Rainfall=7.41 "
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 79
Pond 2P: Sand Filter
Hydrograph
1
53.44 cfs
_ /I50.95 Is 1
55� � /
50� / /
457/ � /
40/ /
i 34.50 cfs
7,35_ 7
o
301
o -
u. 25
20=
15
10-
16 6 cfs
Inflow Are=5.600 ac
Peak Elev=782.90' -
Storage=0.296 of
H -H 1— 4
"7A- 07"/hill/iiiiiii0' -6 7".hill./Z7,40 -60'-i07,./ZZW/Zi /Z6,iiiiiii
5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)
Pond 2P: Sand Filter
Stage -Discharge
40 50
Discharge (cfs)
60
70
80
90
❑ Inflow
❑ Outflow
❑ Primary
❑ Secondary
❑ Total
❑ Primary
❑ Secondary

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation (feet)
Pond 2P: Sand Filter
Stage -Area -Storage
Surface/Horizontal/Wetted Area (acres)
0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09
Type 11 24-hr 100-yr Rainfall=7.41 "
Printed 5/19/2021
Page 80
0.1
0.11
0.12
783-'
782 '
781-
780-
779
II
II
II
I I II
I I I
I I I II
II I I I II
Ji
K K... ...K...K...K. .. K... ...K. .. ...K. .. .../
0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 0.18 0.2 0.22 0.24 0.26 0.28 0.3 0.32 0.34 0.36
Storage (acre-feet)
Surface
❑ Storage

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Time Inflow
(hours) (cfs)
0.00 0.00
2.50 0.00
5.00 0.07
7.50 0.32
10.00 0.94
12.50 4.08
15.00 1.21
17.50 0.78
20.00 0.53
22.50 0.47
25.00 0.00
27.50 0.00
30.00 0.00
32.50 0.00
35.00 0.00
37.50 0.00
40.00 0.00
42.50 0.00
45.00 0.00
47.50 0.00
50.00 0.00
52.50 0.00
55.00 0.00
57.50 0.00
60.00 0.00
62.50 0.00
65.00 0.00
67.50 0.00
70.00 0.00
72.50 0.00
75.00 0.00
77.50 0.00
80.00 0.00
82.50 0.00
85.00 0.00
87.50 0.00
90.00 0.00
92.50 0.00
95.00 0.00
97.50 0.00
100.00 0.00
102.50 0.00
105.00 0.00
107.50 0.00
110.00 0.00
112.50 0.00
115.00 0.00
117.50 0.00
120.00 0.00
Hydrograph for Pond 2P: Sand Filter
Storage
(acre-feet)
0.000
0.000
0.003
0.039
0.089
0.097
0.090
0.088
0.087
0.087
0.081
0.072
0.062
0.054
0.046
0.039
0.033
0.028
0.023
0.019
0.016
0.014
0.011
0.009
0.008
0.007
0.005
0.005
0.004
0.003
0.003
0.002
0.002
0.001
0.001
0.001
0.001
0.001
0.001
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
0.000
Elevation
(feet)
779.00
779.00
779.06
779.76
780.56
780.69
780.58
780.56
780.54
780.54
780.46
780.31
780.16
780.02
779.88
779.76
779.65
779.56
779.48
779.40
779.34
779.29
779.24
779.20
779.17
779.14
779.12
779.10
779.08
779.07
779.06
779.05
779.04
779.03
779.03
779.02
779.02
779.02
779.01
779.01
779.01
779.01
779.01
779.01
779.00
779.00
779.00
779.00
779.00
Outflow
(cfs)
0.00
0.00
0.00
0.03
0.92
4.30
1.22
0.78
0.53
0.47
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Primary
(cfs)
0.00
0.00
0.00
0.03
0.92
4.30
1.22
0.78
0.53
0.47
0.05
0.05
0.04
0.04
0.04
0.03
0.03
0.02
0.02
0.02
0.01
0.01
0.01
0.01
0.01
0.01
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Type 11 24-hr 100-yr Rainfall=7.41 "
Printed 5/19/2021
Page 81

7544-Sand Filter
Prepared by {enter your company name here}
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC
Elevation Discharge
(feet) (cfs)
779.00 0.00
779.05 0.00
779.10 0.00
779.15 0.01
779.20 0.01
779.25 0.01
779.30 0.01
779.35 0.01
779.40 0.02
779.45 0.02
779.50 0.02
779.55 0.02
779.60 0.02
779.65 0.03
779.70 0.03
779.75 0.03
779.80 0.03
779.85 0.03
779.90 0.04
779.95 0.04
780.00 0.04
780.05 0.04
780.10 0.04
780.15 0.04
780.20 0.04
780.25 0.04
780.30 0.05
780.35 0.05
780.40 0.05
780.45 0.05
780.50 0.05
780.55 0.63
780.60 1.71
780.65 3.09
780.70 4.73
780.75 6.59
780.80 8.65
780.85 10.89
780.90 13.29
780.95 13.49
781.00 13.57
781.05 13.65
781.10 13.74
781.15 13.82
781.20 13.90
781.25 13.98
781.30 14.06
781.35 14.15
781.40 14.23
781.45 14.30
781.50 14.38
781.55 14.46
781.60 14.54
Stage -Discharge for Pond 2P: Sand Filter
Primary
(cfs)
0.00
0.00
0.00
0.01
0.01
0.01
0.01
0.01
0.02
0.02
0.02
0.02
0.02
0.03
0.03
0.03
0.03
0.03
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.04
0.05
0.05
0.05
0.05
0.05
0.63
1.71
3.09
4.73
6.59
8.65
10.89
13.29
13.49
13.57
13.65
13.74
13.82
13.90
13.98
14.06
14.15
14.23
14.30
14.38
14.46
14.54
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
Elevation Discharge
(feet) (cfs)
781.65 14.62
781.70 14.70
781.75 14.77
781.80 14.85
781.85 14.93
781.90 15.00
781.95 15.08
782.00 15.15
782.05 15.65
782.10 16.48
782.15 17.55
782.20 18.79
782.25 20.23
782.30 21.82
782.35 23.57
782.40 25.46
782.45 27.57
782.50 29.83
782.55 32.26
782.60 34.85
782.65 37.30
782.70 39.85
782.75 42.47
782.80 45.18
782.85 47.97
782.90 50.84
782.95 53.78
783.00 56.79
783.05 59.95
783.10 63.19
783.15 66.51
783.20 69.90
783.25 73.21
783.30 76.58
783.35 80.00
783.40 83.47
783.45 86.92
783.50 90.42
Primary
(cfs)
14.62
14.70
14.77
14.85
14.93
15.00
15.08
15.15
15.23
15.30
15.38
15.45
15.52
15.60
15.67
15.74
15.81
15.89
15.96
16.03
16.10
16.17
16.24
16.31
16.38
16.45
16.52
16.59
16.66
16.72
16.79
16.86
16.93
16.99
17.06
17.13
17.19
17.26
Type 11 24-hr 100-yr Rainfall=7.41 "
Printed 5/19/2021
Page 82
Secondary
(cfs)
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.42
1.18
2.17
3.34
4.70
6.22
7.90
9.71
11.75
13.95
16.31
18.82
21.20
23.68
26.23
28.87
31.59
34.39
37.26
40.20
43.29
46.46
49.71
53.04
56.29
59.59
62.94
66.34
69.73
73.16

7544-Sand Filter Type 11 24-hr 100-yr Rainfall=7.41 "
Prepared by {enter your company name here} Printed 5/19/2021
HydroCAD® 10.00-24 s/n 10182 © 2018 HydroCAD Software Solutions LLC Page 83
Stage -Area -Storage for Pond 2P: Sand Filter
Elevation Surface Storage Elevation Surface Storage
(feet) (acres) (acre-feet) (feet) (acres) (acre-feet)
779.00 0.045 0.000 781.65 0.087 0.173
779.05 0.046 0.002 781.70 0.088 0.177
779.10 0.047 0.005 781.75 0.088 0.181
779.15 0.047 0.007 781.80 0.089 0.186
779.20 0.048 0.009 781.85 0.090 0.190
779.25 0.049 0.012 781.90 0.091 0.195
779.30 0.049 0.014 781.95 0.092 0.199
779.35 0.050 0.017 782.00 0.093 0.204
779.40 0.051 0.019 782.05 0.094 0.209
779.45 0.052 0.022 782.10 0.095 0.213
779.50 0.052 0.024 782.15 0.096 0.218
779.55 0.053 0.027 782.20 0.097 0.223
779.60 0.054 0.030 782.25 0.098 0.228
779.65 0.055 0.032 782.30 0.098 0.233
779.70 0.056 0.035 782.35 0.099 0.238
779.75 0.056 0.038 782.40 0.100 0.243
779.80 0.057 0.041 782.45 0.101 0.248
779.85 0.058 0.044 782.50 0.102 0.253
779.90 0.058 0.047 782.55 0.103 0.258
779.95 0.059 0.050 782.60 0.104 0.263
780.00 0.060 0.052 782.65 0.105 0.268
780.05 0.061 0.056 782.70 0.106 0.274
780.10 0.062 0.059 782.75 0.106 0.279
780.15 0.062 0.062 782.80 0.107 0.284
780.20 0.063 0.065 782.85 0.108 0.290
780.25 0.064 0.068 782.90 0.109 0.295
780.30 0.064 0.071 782.95 0.110 0.300
780.35 0.065 0.074 783.00 0.111 0.306
780.40 0.066 0.078 783.05 0.112 0.312
780.45 0.067 0.081 783.10 0.113 0.317
780.50 0.068 0.084 783.15 0.114 0.323
780.55 0.068 0.088 783.20 0.115 0.329
780.60 0.069 0.091 783.25 0.116 0.334
780.65 0.070 0.095 783.30 0.117 0.340
780.70 0.071 0.098 783.35 0.118 0.346
780.75 0.071 0.102 783.40 0.119 0.352
780.80 0.072 0.105 783.45 0.120 0.358
780.85 0.073 0.109 783.50 0.121 0.364
780.90 0.073 0.113
780.95 0.074 0.116
781.00 0.075 0.120
781.05 0.076 0.124
781.10 0.077 0.128
781.15 0.078 0.131
781.20 0.079 0.135
781.25 0.079 0.139
781.30 0.080 0.143
781.35 0.081 0.147
781.40 0.082 0.151
781.45 0.083 0.156
781.50 0.084 0.160
781.55 0.085 0.164
781.60 0.086 0.168

4/28/2021
Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: Denver, North Carolina, USA*
Latitude: 35.4689°, Longitude: -81.0071°
Elevation: 785.21 ft**
* source: ESRI Maps
** source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1
Duration
5-min
10-min
15-min
30-min
60-min
2-hr
3-hr
6-hr
12-hr
24-hr
2-day
3-day
4-day
7-day
10-day
20-day
30-day
45-day
60-day
Average recurrence interval (years)
1
0.388
(0.357-0.421)
0.620
(0.571-0.673)
0.775
(0.714-0.841)
1.06
(0.978-1.15)
1.32
(1.22-1.44)
1.54
(1.41-1.68)
1.64
(1.51-1.80)
2.01
(1.85-2.19)
2.41
(2.23-2.62)
2.80
(2.61-3.02)
3.30
(3.06-3.54)
3.50
(3.26-3.76)
3.71
(3.46-3.97)
4.28
(4.02-4.57)
4.90
(4.62-5.22)
6.58
(6.24-6.94)
8.11
(7.73-8.52)
10.2
(9.77-10.7)
12.1
(11.7-12.7)
2
0.458
(0.422-0.499)
0.733
(0.676-0.798)
0.921
(0.849-1.00)
1.27
(1.17-1.39)
1.60
(1.47-1.74)
1.86
(1.71-2.03)
1.98
(1.82-2.17)
2.42
(2.23-2.65)
2.91
(2.68-3.17)
3.39
(3.15-3.66)
3.97
(3.70-4.28)
4.21
(3.93-4.53)
4.45
(4.16-4.78)
5.12
(4.80-5.45)
5.84
(5.49-6.22)
7.77
(7.37-8.20)
9.54
(9.10-10.0)
11.9
(11.4-12.5)
14.1
(13.6-14.7)
5
0.535
(0.492-0.583)
0.858
(0.788-0.933)
1.09
(0.997-1.18)
1.54
(1.42-1.68)
1.98
(1.82-2.15)
2.32
(2.12-2.53)
2.48
(2.27-2.72)
3.03
(2.79-3.31)
3.64
(3.36-3.97)
4.26
(3.96-4.60)
4.96
(4.61-5.34)
5.23
(4.87-5.62)
5.50
(5.13-5.89)
6.23
(5.84-6.64)
7.02
(6.60-7.47)
9.18
(8.69-9.68)
11.1
(10.5-11.6)
13.6
(13.0-14.2)
15.9
(15.3-16.6)
10
0.592
(0.542-0.643)
0.947
(0.867-1.03)
25
0.657
(0.599-0.713)
1.05
(0.954-1.14)
50
0.703
(0.637-0.762)
1.12
(1.01-1.21)
100
0.745
(0.671-0.809)
1.18
(1.07-1.29)
200
0.783
(0.701-0.852)
1.24
(1.11-1.35)
500
0.827
(0.732-0.904)
1.31
(1.16-1.43)
1000
0.859
(0.752-0.942)
1.35
(1.19-1.48)
1.20
1.33
1.42
1.50
1.57
1.65 I
1.70
(1.10-1.30)
(1.21-1.44)
(1.29-1.54)
(1.35-1.62)
(1.40-1.71)
(1.46-1.80)
(1.49-1.86)
1.74
1.97
2.13
2.29
2.44
2.62
2.75
(1.59-1.88)
(1.79-2.13)
(1.94-2.32)
(2.07-2.49)
(2.18-2.65)
(2.32-2.87)
(2.41-3.02)
2.26
(2.07-2.45)
2.62
(2.39-2.84)
2.89
(2.62-3.14)
3.16
(2.85-3.43)
3.42
(3.06-3.72)
3.76
(3.33-4.11)
4.01
(3.52-4.40)
2.66
3.12
3.48
3.83
4.18
4.66
5.02
(2.43-2.90)
(2.84-3.40)
(3.14-3.79)
(3.44-4.18)
(3.72-4.58)
(4.09-5.11)
(4.36-5.53)
2.87
3.39
3.82
4.24
4.68
5.29 5.76
(2.62-3.14)
(3.08-3.71)
(3.44-4.17)
(3.79-4.64)
(4.15-5.13)
(4.61-5.82) (4.97-6.37)
3.51
(3.22-3.82)
4.16
(3.79-4.52)
4.68
(4.24-5.09)
5.22
(4.69-5.68)
5.78
(5.13-6.29)
6.55
(5.73-7.15)
7.16
(6.18-7.83)
4.23
5.04 5.70
6.37
7.08
8.07
8.86
(3.89-4.60)
(4.60-5.47) (5.15-6.17)
(5.71-6.89)
(6.27-7.66)
(7.03-8.73)
(7.61-9.60)
4.95
5.89
6.64
7.41
8.19
9.27
10.1
(4.60-5.34)
(5.45-6.35)
(6.13-7.15)
(6.81-7.98)
(7.51-8.83)
(8.45-10.0)
(9.20-10.9)
5.73
(5.32-6.16)
6.03
(5.60-6.47)
6.33
(5.88-6.78)
7.11
(6.65-7.57)
7.93
(7.45-8.44)
10.3
(9.72-10.8)
12.2
(11.6-12.8)
14.9
(14.2-15.5)
17.3
(16.6-18.0)
6.78
(6.28-7.29)
7.61
(7.03-8.18)
8.46
(7.79-9.09)
9.32
(8.56-10.0)
10.5
(9.61-11.3)
11.4
(10.4-12.3)
7.12
7.98
8.86
9.75
11.0
11.9
(6.59-7.63)
(7.37-8.56)
(8.16-9.50)
(8.96-10.5)
(10.1-11.8)
(10.9-12.8)
7.45
8.35
9.25
10.2
11.5 12.5
(6.91-7.98)
(7.71-8.94)
(8.53-9.92)
(9.37-10.9)
(10.5-12.3) (11.4-13.4)
8.31
(7.75-8.84)
9.15
(8.57-9.74)
11.7
(11.1-12.4)
13.8
(13.1-14.4)
16.5
(15.7-17.2)
19.1
(18.3-19.9)
9.25
(8.61-9.86)
10.1
(9.45-10.8)
12.9
(12.1-13.6)
14.9
(14.1-15.7)
17.7
(16.9-18.5)
20.4
(19.5-21.3)
10.2
(9.48-10.9)
11.1
(10.3-11.8)
14.0
(13.2-14.8)
16.1
(15.2-16.9)
18.9
(18.0-19.8)
21.7
(20.7-22.6)
11.2
(10.4-12.0)
12.0
(11.2-12.8)
15.2
(14.2-16.1)
17.2
(16.2-18.1)
20.0
(19.0-21.0)
22.9
(21.9-24.0)
12.5
(11.6-13.4)
13.3
(12.4-14.2)
16.8
(15.7-17.8)
18.7
(17.6-19.7)
21.5
(20.4-22.6)
24.5
(23.3-25.7)
13.6
(12.5-14.5)
14.4
(13.3-15.3)
18.0
(16.7-19.1)
19.9
(18.6-21.0)
22.7
(21.4-23.8)
25.7
(24.4-26.9)
1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS)
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability hat precipitation frequency estimates (for a
given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to Top
PF graphical
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.4689&Ion=-81.0071 &data=depth&units=english&series=pds 1/4

4/28/2021 Precipitation Frequency Data Server
Precipitation depth (in)
Precipitation depth (in)
30
25
20
15
10
0
PDS-based depth -duration -frequency (DDF) curves
Latitude: 35.4689', Longitude:-81.0071'
I I
C C
J Ln
r-I r I
Duration
• c9
N r9 n ro r4 r4 r4 r9 r4
N rh r N O 0 0 WI
r-I CV rn V to
2 5 10 25 50 100 200 500 1000
NDAAAtlas 14, Volume 2, Version 3
Average recurrence interval (years)
Created (GMT): Wed Apr 28 14:15:49 2021
Back to Top
Maps & aerials
Small scale terrain
Average recurrence
InIerval
{years)
— 1
2
— 5
— 10
— 25
— 50
— 100
— 200
— 500
— 1000
Duration
5-min
10-min
15-min
30-min
60-min
2-hr
3-hr
6-hr
12-hr
24-hr
2-day
3-day
4--day
7-day
10-day
20-aay
30-day
45-day
60-day
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.4689&Ion=-81.0071 &data=depth&units=english&series=pds 2/4

4/28/2021 Precipitation Frequency Data Server
Large scale terrain
KingsportBristol
Johnson City.
r,}
rot klitchIl
'Asheyille
'Greenville
100km
60mi
0
Winston-Salem
• ■ Durham
Greensboro •
NA.TH CAROLINA
'Charlotte
Fay e
TH CAROLINA
Large scale map
Large scale aerial
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.4689&Ion=-81.0071 &data=depth&units=english&series=pds 3/4

4/28/2021 Precipitation Frequency Data Server
KtragRaR_._Brist of
• Johnson CI
•
100km
60mi 1
Winston-Salem
• •::..
Greensboro
Back to Top
US Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring, MD 20910
Questions?: [e-mail]
Disclaimer
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.4689&Ion=-81.0071 &data=depth&units=english&series=pds 4/4

4/28/2021
Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: Denver, North Carolina, USA*
Latitude: 35.4689°, Longitude: -81.0071°
Elevation: 785.21 ft**
* source: ESRI Maps
** source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches/hour)1
Average recurrence interval (years)
Duration
1
2
5
10
25
50
100
200
500 1000
5-min
4.66
(4.28-5.05)
5.50
(5.06-5.99)
6.42
(5.90-7.00)
7.10
(6.50-7.72)
7.88
(7.19-8.56)
8.44
(7.64-9.14)
8.94
(8.05-9.71)
9.40
(8.41-10.2)
9.92
(8.78-10.8)
10.3
(9.02-11.3)
10-min
3.72
(3.43-4.04) I
4.40
(4.06-4.79)
5.15
(4.73-5.60)
5.68
(5.20-6.17)
6.28
(5.72-6.82)
6.71
(6.09-7.28)
7.10
(6.40-7.71)
7.45
(6.66-8.11)
7.85
(6.94-8.58)
8.11
(7.11-8.90)
15-min
3.10
(2.86-3.36)
3.68
(3.40-4.01)
4.34
(3.99-4.72)
4.79
(4.39-5.20)
5.31
(4.84-5.76)
5.67
(5.14-6.15)
5.98
(5.40-6.50)
6.26
(5.60-6.82)
6.59 I
(5.83-7.20)
6.79
(5.95-7.45)
30-min
2.12
(1.96-2.31)
2.55
(2.35-2.77)
3.08
(2.83-3.35)
3.47
(3.18-3.77)
3.93
(3.58-4.26)
4.27
(3.87-4.63)
4.58
(4.13-4.98)
4.88
(4.36-5.31)
5.24
(4.64-5.73)
5.50
(4.82-6.03)
60-min
1.32
(1.22-1.44)
1.60
(1.47-1.74)
1.98
(1.82-2.15)
2.26
(2.07-2.45)
2.62
(2.39-2.84)
2.89
(2.62-3.14)
3.16
(2.85-3.43)
3.42
(3.06-3.72)
3.76
(3.33-4.11)
4.01
(3.52-4.40)
2-hr
0.768
(0.705-0.838)
0.930
(0.854-1.02)
1.16
(1.06-1.26)
1.33
(1.22-1.45)
1.56
(1.42-1.70)
1.74
(1.57-1.89)
1.92 1
(1.72-2.09)
2.09 1
(1.86-2.29)
2.33
(2.05-2.56)
2.51
(2.18-2.76)
3-hr
0.546
(0.502-0.598)
0.659
(0.606-0.723)
0.825
(0.757-0.905)
0.955
(0.872-1.04)
1.13
(1.03-1.24)
1.27
(1.15-1.39)
1.41
(1.26-1.54)
1.56
(1.38-1.71)
1.76
(1.54-1.94)
1.92
(1.65-2.12)
6-hr
0.336
(0.309-0.366)
0.404
(0.373-0.442)
0.506
(0.466-0.552)1
0.586
(0.537-0.638)1
0.695
(0.633-0.755)1
0.782
(0.709-0.850)
0.872
(0.783-0.949)
0.965
(0.857-1.05)
1.09
(0.956-1.19)
1.20
(1.03-1.31)
12-hr
0.200
(0.185-0.217)
0.241
(0.223-0.263)
0.302
(0.279-0.329)
0.351
(0.323-0.382)
0.419
(0.382-0.454)
0.473
(0.428-0.512)
0.529
(0.474-0.572)
0.588
(0.520-0.636)
0.670
(0.584-0.724)
0.735
(0.632-0.797)
24-hr
0.117
(0.109-0.126)
0.141
(0.131-0.152)
0.178
(0.165-0.192)
0.206
(0.191-0.222)
0.246
(0.227-0.265)
0.277
(0.255-0.298)
0.309
(0.284-0.332)
0.341
(0.313-0.368)
0.386
(0.352-0.417)
0.422
(0.383-0.456)
2-day
0.069
(0.064-0.074)
0.083
(0.077-0.089)
0.103
(0.096-0.111)
0.119
(0.111-0.128)
0.141
(0.131-0.152)
0.159
(0.146-0.170)
0.176
(0.162-0.189)
0.194
(0.178-0.209)
0.219
(0.200-0.236)
0.238
(0.217-0.256)
3-day
0.049
(0.045-0.052)
0.059
(0.055-0.063)
0.073
(0.068-0.078)
0.084
(0.078-0.090)
0.099
(0.092-0.106)
0.111
(0.102-0.119)
0.123
(0.113-0.132)
0.135
(0.125-0.145)
0.153
(0.140-0.164)
0.166
(0.151-0.178)
4-day
0.039
(0.036-0.041)
0.046
(0.043-0.050)
0.057
(0.053-0.061)
0.066
(0.061-0.071)
0.078
(0.072-0.083)
0.087
(0.080-0.093)
0.096
(0.089-0.103)
0.106
(0.098-0.114)
0.119
(0.109-0.128)
0.130
(0.118-0.139)
7-day 0.025
(0.024-0.027)
0.030
(0.029-0.032)
0.037
(0.035-0.039)
0.042
(0.040-0.045)
0.049
(0.046-0.053)
0.055
(0.051-0.059)
0.061
(0.056-0.065)
0.067
(0.062-0.071)
0.075
(0.069-0.080)
0.081
(0.074-0.087)
10-day 0.020
(0.019-0.022)
0.024
(0.023-0.026)
0.029
(0.027-0.031)
0.033
(0.031-0.035)
0.038
(0.036-0.041)
0.042
(0.039-0.045)
0.046
(0.043-0.049)
0.050
(0.047-0.053)
0.056
(0.052-0.059)
0.060
(0.055-0.064)
20-day
0.014 0.016 0.019 0.021 0.024
(0.013-0.014) (0.015-0.017) (0.018-0.020) (0.020-0.023) (0.023-0.026)
0.027
(0.025-0.028)
0.029 0.032
(0.027-0.031) (0.030-0.034)1
0.035 0.037
(0.033-0.037) (0.035-0.040)1
30-day
0.011
(0.011-0.012)
0.013
(0.013-0.014)
0.015
(0.015-0.016)
0.017
(0.016-0.018)
0.019
(0.018-0.020)
0.021
(0.020-0.022)
0.022
(0.021-0.023)
0.024
(0.023-0.025)
0.026
(0.024-0.027)
0.028
(0.026-0.029)
45-day
0.009
(0.009-0.010)
0.011
(0.011-0.012)
0.013
(0.012-0.013)
0.014
(0.013-0.014)
0.015
(0.015-0.016)
0.016
(0.016-0.017)
0.017
(0.017-0.018)
0.019
(0.018-0.019)
0.020
(0.019-0.021)
0.021
(0.020-0.022)
60-day 0.008 0.010 0.011 0.012 0.013 0.014 0.015 0.016
(0.008-0.009) (0.009-0.010) (0.011-0.012) (0.012-0.013) (0.013-0.014) (0.014-0.015) (0.014-0.016) (0.015-0.017)
0.017 0.018
(0.016-0.018) (0.017-0.019)
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 hat precipitation frequency estimates (for a
given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to Top
PF graphical
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.4689&Ion=-81.0071 &data=intensity&units=english&series=pds 1/4

4/28/2021
Precipitation Frequency Data Server
Precipitation intensity (in{hr}
Precipitation intensity (in{hr}
PDS-based intensity -duration -frequency (IDF) curves
Latitude: 35.4689", Longitude:-81.0071'
E
Y']
100.000
10.000
1.000
0.100
0.010
0.001
1 2
NOAA Atlas 14, Volume 2, Version 3
Duration
•
N r to N r
to r4 r4 r9 4
N rh r r- O 0 0 WI
rl CV rn V to
10 25 50 100 200
Average recurrence interval (years)
500 1000
Created (GMT): Wed Apr 28 14:19:26 2021
Back to Top
Maps & aerials
Small scale terrain
Average recurrence
Interval
{years)
1
2
5
10
25
50
100
200
500
1000
Duration
5-min
10-mon
15-mon
30-min
50-mm
2-hr
3-hr
6-hr
12-hr
24-hr
2-day
3-day
4--day
7-day
10-day
20-aay
30-day
45-day
60-day
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?tat=35.4689&Ion=-81.0071 &data=intensity&units=english&series=pds 2/4

4/28/2021 Precipitation Frequency Data Server
Large scale terrain
KingsportBristol
Johnson City.
r,}
rot kilitchIl
'Asheyille
'Greenville
100km
60mi
0
Winston-Salem
• ■ Durham
Greensboro •
NA.TH CAROLINA
'Charlotte
Fay e
TH CAROLINA
Large scale map
Large scale aerial
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.4689&Ion=-81.0071 &data=intensity&units=english&series=pds 3/4

4/28/2021 Precipitation Frequency Data Server
KtragRaR_._Brist of
• Johnson CI
•
100km
60mi 1
Winston-Salem
• •::..
Greensboro
Back to Top
US Department of Commerce
National Oceanic and Atmospheric Administration
National Weather Service
National Water Center
1325 East West Highway
Silver Spring, MD 20910
Questions?: [e-mail]
Disclaimer
https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=35.4689&Ion=-81.0071 &data=intensity&units=english&series=pds 4/4