20181259 Ver 3_2022_05_18 Rivercross SMP Report_20220519

STORMWATER MANAGEMENT PLAN REPORT
FOR
RIvE RCROSS
Catawba Springs, Lincoln County, NC
AMH Rivercross Development TRS, LLC
16905 Northcross Drive, Suite 200
Huntersville, NC 28078
Date: 12.20.18
Revised: 05.18.22
URBAN
DESIGN
PARTNERS
UDP Project No: 18-001
Calculations By: udp
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05.18.2022

SolL MAP

3 Hydrologic Soil Group—Lincoln County, North Carolina 3
(SCM Drainage Boundary Soil Map) 4
0 81
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493110 49-4300 MOM 50010E 50020E
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I�P Prr:Web hl�ramr Gorr�er ooadra[es vYC84 tics:UM Zane 17N vYC84
tisrm Natural Resources Web Soil Survey
r Conservation Service National Cooperative Soil Survey

Hydrologic Soil Group —Lincoln County, North Carolina
(SCM Drainage Boundary Soil Map)
MAP LEGEND MAP INFORMATION
Area of Interest (AOl)
Area of Interest (AOl)
Soils
Soil Rating Polygons
0 A
0 ND
0
0 BID
0 C
CID
0 D
0 Not rated or not available
Soil Rating Lines
• A
r • ND
,.y B/D
0 C
▪ CID
• D
O Not rated or not available
Water Features
Streams and Canals
Transportation
}-1-4- Rails
ans. Interstate Highways
US Routes
Major Roads
Local Roads
Background
I. Aerial Photography
The soil surveys that comprise your A01 were mapped at
1:24,000.
Waming: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
B This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
. r C
. • CID
. ,. D
. w Not rated or not available
Soil Rating Points
A The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
G A/D imagery displayed on these maps. As a result, some minor
• B shifting of map unit boundaries may be evident.
• BID
Soil Survey Area: Lincoln County, North Carolina
Survey Area Data: Version 22, Sep 10, 2018
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Apr 8, 2015 Nov 28,
2017
USDA Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey

Hydrologic Soil Group —Lincoln County, North Carolina
SCM Drainage Boundary Soil Map
Hydrologic Soil Group
Map unit symbol
Map unit name
Rating
Acres in AOI
Percent of AOl
CeB2
Cecil sandy clay loam, 2
to 8 percent slopes,
moderately eroded
B
32.2
61.8%
LdB2
Lloyd sandy clay loam, 2
to 8 percent slopes,
moderately eroded
B
5.2
10_0%
PeC2
Pacolet sandy clay
loam, 8 to 15 percent
slopes, moderately
eroded
B
14.7
28.3%
Totals for Area of Interest
521
100.0%
(JSi)A Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey

Hydrologic Soil Group —Lincoln County, North Carolina SCM Drainage Boundary Soil Map
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long -duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (ND, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink -swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, BID, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff. None Specified
Tie -break Rule: Higher
iisnm Natural Resources Web Soil Survey
Conservation Service National Cooperative Soil Survey

STORM DRAINAGE
PIPE CALCULATIONS

Rivercross
JOB NO.: 18-001
BY: udp
DATE:
06.01.18
P.M.: Ibr
REVISED:
08.03.20
Urban Design Partners
1318-E6 Central Avenue
Charlotte, NC 28205
Storm Drainage Design Data
STRUCTURE I❑
DRAINAGE
AREA
RUNOFF
C i
_
PIPE
_
512E
(Inches)
VELOCITY
ACTUAL
INVERT ELEV.
UPSTREAM I DOWNSTREAM
INV INV
OUT IN
COVER
UPSTREAM
PIPE
MATERIAL
UPSTREAM
UPSTREAM
DOWNSTREAM
(acres)
Qinlet
(Cis)
Qpipe
(cfs)
n
SLOPE LENGTH
(%) (ft)
CAPACITY
VEL.
(fps)
RIM
ELEVATION
COVER
DEPTH
(FROM)
(TO)
(cfsy
SD200 - PIPE NETWORK
CB-220
CB-201
0.17
0.80
6.29
0.9
11.1
0.013
1.15% 39
18
11.30
7.73
762.25
761.80
769.43
5.47
RCP III
CB-202
CB-201
0.11
0.80
6.29
0.6
9.2
0.013
3.45% 148
15
12.04
11.18
768.50
763.40
776.10
6.17
RCP III
06-201
FES-200
0.15
0.80
629
0.7
21.0
0.013
0.96% 31
24
22.27
8.51
761.30
761.00
769.43
5.88
I RCP III
OCS-2002
JB-2001
0.00
0.80
6.29
0.0
18.8
0.013
0.76% 33
24
19.83
7.58
758.00
757.75
765.00
4.75
RCP III
RCP III
JB-2001
FES-2000
0.00
0.80
6.29
0.0
18.8
0.013
0.97% 77
24
22.35
8.25
757.75
757.00
766.00
6.00
ISD300
- PIPE NETWORK
01-302
DI-301
0.12
0.80
6.29
0.6
34.8
0.013
0.82% 184
30
37.13
9.08
750.00
748.50
767.50
14.75
HOPE
DI-301
FES-300
0.16
0.80
6.29
0.8
35.6
0.013
0.82% i 61
30
37.14
9.16
748.50
748.00
765.25
14.00
HOPE
1
0.00
0.80
6.29
27.9
0.013
30
RCP
OCS-3001
. HW-3000 1
0.0
0.64% 39
32.96
7.79
745.00
744.75
752.50
4.71
5D400 - PIPE NETWORK
CB-451B
CB-451A
0.24
0.70
6.29
1.1
1.1
0.013
0.59% 34 15
4.97
3.08
747.40
747.20
751.00
2.16
RCPV
CB-451A 'I
CB-451
0.09
0.08
0.25
0.70
6.29 1
0.4
1.5
0.013
0.57% 141
15
4.89
3.38
747.20
748.40
750.85
2.21
RCP V
i
0.90
2.3
0.013
0.013
RCP Ili
RCP Ili
RCP III
RCP III
RCP Ill
RCP III
RCP III
00-452
I 00-451
629 I
0.4
0.74% 34
18
9.03
4.14
I 750.00
749.75
755.19
3A8
06-451
HW-450
0.90
6.29
1.4
5.2
0.71 % 21
18
8.85
5.16
746.15
746.00
755.14
7.28
I
OCS-4501
FES-4500
0.00
0.70
6.29
0.0
11.7
0.013
1.00% 50
24
22.72
7.23
743.00
742.50
749.10
3.85
I
08-405
08-404
0.12
0.95
6.29
0.7
10.4
0.013
1.00% 40
18
10.54
7.22
760.20
759.80
765.55
3.64
00-404
I JB-401
0.06
0.95
6.29 1
0.3
10.7
0.013
2.95% I 51
18
18.10
10.55
755.00
753.50 1
765.60
8.89
09-403
CB-402
0.15
0.80
6.29 I
0.8
0.8 1
0.013
0.79% 38
15
5.76
2.82
760.30
780.00
764.23
2.49
06-402
JB-401
0.06
0.95
6.29
0.3
8.7
0.013
8.90% 51
15
19.33
14.49
758.00
753.50
764.14
4.70
JB-401
I FES-400
0.00
0.95
629 I
0.0
19.4
0.013
1.69% I 12
24
29.51
1024
753.20
753.00
759.00
3.55
RCP III
005-4001
I FES-4000
0.00
0.95
6.29 I
0.0
5.2
0.013
1.44% I 104
18
12.62
6.57
749.50
748.00
756.50
5.29
RCP III

Rivercross
JOB NO.:
DATE:
REVISED:
18-001
06.01.18
08.03.20
BY: udp
P.M.: Ibr
Urban Design Partners
1318-E6 Central Avenue
Charlotte, NC 28205
Storm Drainage Design Data
STRUCTURE I❑
DRAINAGE
AREA
RUNOFF
C 1
I
PIPE
VELOCITY
ACTUAL
INVERT
UPSTREAM
INV
ELEV.
I DOWNSTREAM
INV
IN
COVER
UPSTREAM
PIPE
MATERIAL
UPSTREAM
UPSTREAM
DOWNSTREAM
Q inlet
Q pipe
n
SLOPE LENGTH
(%) ((t)
512E
(Inches)
CAPACITY VEL.
RIM
ELEVATION
COVER
DEPTH
(FROM)
(TO)
(acres)
I (Cfs}
(cfs)
(c sy (Vs)
OUT
SO600 - PIPE NETWORK
CB-653 FS-652
0.14
0.80
6.29 0.7
28.2
0.013
0.55% 36
30
30.54
7.47
734.20
734.00
744.63
7.64
RCP III
FS-652 JB-651
0.00
0.70
6.29 0.0
28.2
0.013
3.22% 72
30
73.75
13.37
733.50
731.20
743.00
6.75
HDPE
JB-651 HW-650
0.00
0.70
6.29 0.0
29.2
0.013
0.91% 11
30
39.28
8.96
731.20
731.10
736.50
2.55
I HDPE
FS-#h9 ST-6
-
0.70
6.29 0.0
7.6
0.013
0.54% 15
18
7.73
5.25
734.00
733.92
743.00
7.33
I HDPE
ST-6 BF-6
-
0.70
6.29 0.0
1.0
0.013
2.33% 5
12
5.45
4.72
I 734.25
734.13
743.00
7.65
HDPE
BF-6 JB-651
-
0.70
6.29 0.0
1.0
0.013
1.0096 10
12
3.57
3.68
731.30
731.20
740.00
7.60
I HDPE
JB-604 FS-603
0.00
0.70
6.29 0.0
8.1
0.013
0.76% 52
18
9.21
6.15
749.00
748.60
755.65
4.98
HDPE
FS-603 JB-602
0.00
0.70
0.70
6.29 0.0
8.1
0.013
0.013
1.67% 15
18
13.60
7.93
1 748.00
747.75
754.50
4.83
HDPE
I HDPE
JB-602 JB-601
0.00
6.29
0.0
8.1
2.0796 68
18
15.15
8.57
747.75
746.35
754.50
5.08
JB-601 I-IW-600
0.00
0.70
6.29I
0.0
8.1
0.013
1.3196 11
18
12.06
7.44
746.15
746.00
750.50
2.68
HDPE
I
00-603B T CO-603A
0.18
0.95
6.29T
1.1
1.1
0.013
2.45%T 98
8
1.90
5.60
752.50
750.10
755.10
1.69
HDPE
CO-603A BF-5
0.05
0.95
6.29 0.3
1.4
0.013
1.4796 50
8
1.47
5.04
749.90
749.17
751.81
1.20
I HDPE
FS-603 ST-5
-
0.70
6.29 0.0
2.1
0.013
0.73% 8
12
3.05
4.23
748.60
748.54
754.50
4.73
I RCP III
ST-5 BF-5
-
0.70
6.29
0.0
1.0
0.013
1.13% 9
12
3.80
3.92
I 747.60
747.50
754.00
5.30
HDPE
BF-5 JB-601
-
0
0.70
6.29 0.0
1.0
0.013
0.57% 26
8
0.91
3.14
746.50
746.35
752.00
4.79
HDPE

Rivercross
Urban Design Partners
1213 West Morehead St Suite 450
Charlotte, NC 28208
JOB NO.:
18-DD1
BY:
udp
DATE:
05.30.19
P.M.:
BDS
REVISED:
5/18/22
Storm Drainage Design Data
STRUCTURE ID
DRAINAGE
RUNOFF
PIPE
VELOCITY
INVERT ELEV.
COVER
AREA
REO'❑
ACTUAL
UPSTREAM
DOWNSTREAM
UPSTREAM
UPSTREAM
UPSTREAM
DOWNSTREAM
C
I
0 inlet
0 pipe
n
SLOPE
LENGTH
SIZE
SIZE
CAPAC[IY VEL.
INV
INV
RIM
COVER
PIPE
(FROM)
(TO)
(acres)
(cfs)
(cfs)
(%)
(ft)
(inches)
(inches)
(cfs) (fps)
OUT
IN
ELEVATION
DEPTH
MATERIAL
SD700 - PIPE NETWORK
DCB-742
DCB-741
0.26
0.95
6.29
1.5
1.5
0.013
0.54%
28
9.8
15
4.74
3.28
753.10
752.95
756.37
1.84
RCPV
DCB-741
CB-740
0.15
0.95
629
0.9
2.4
0.013
0.58%
38
11.5
15
4.91
3.84
752.95
752.73
756.37
1.99
RCPV
CB-740
CB-701
0.31
0.95
6.29
1.8
4.2
0.013
0.60%
38
14.1
15
5.02
4.75
752.73
752.50
756.97
2.80
RCP V
CB-703
CB-702
0.02
0.95
6.29
0.1
25.3
0.013
3.07%
65
20.3
24
39.72
13.40
755.50
753.50
763.95
6.20
RCP III
CB-702
CB-701
0.04
0.95
629
0.2
25.5
0.013
2.97%
45
20.4
24
39.07
13.56
753.5D
752.15
760.00
4.25
RCP III
CB-701
FS-700
0.03
0.95
6.29
0.2
29.9
0.013
1.01%
15
26.5
30
41.40
9.45
751.65
751.50
757.88
3.44
RCP III
FS-700
JB-7002
0.00
0.95
6.29
0.0
29.9
0.013
4.80%
31
19.8
30
90.09
15.6D
751.DD
749.50
758.25
4.46
RCP III
JB-7002
JB-7001
0.00
0.95
6.29
0.0
30.9
0.013
0.73%
68
28.6
30
35.15
8.45
749.50
749.00
759.50
7.21
RCP III
JB-7001
HW-7000
0.00
0.95
6.29
0.0
30.9
0.013
0.57%
21
29.9
36
50.70
7.6D
749.DD
748.88
759.25
6.92
RCP III
CB-702
BF-8
-
0.85
6.29
0.0
3.0
0.013
9.76%
23
7.3
8
3.79
12.36
753.5D
751.27
760.00
5.79
HDPE
FS-700
JB-7003
-
0.85
6.29
0.0
7.2
0.013
0.62%
8
17.1
18
8.30
5.54
751.50
751.45
758.25
5.04
RCP III
JB-7003
ST-8
-
0.85
6.29
0.0
7.2
0.013
0.61%
24
17.1
18
8.26
5.51
751.45
751.30
758.75
5.63
HDPE
ST-8
BF-8
-
0.85
6.29
0.0
1.0
0.013
0.71%
6
7.9
12
3.02
3.27
751.24
751.20
761100
7.66
HDPE
BF-8
JB-7002
-
0.85
8.29
0.0
1.0
0.013
0.74%
14
7.9
12
3.07
3.33
749.60
749.50
760.00
9.30
HDPE
SD800 - PIPE NETWORK
JB-803
DI-802
0.15
0.80
6.29
0.8
40.6
0.013
0.59%
119
33.0
38
51.23
8.26
739.5D
738.8D
748.50
5.67
RCP III
DI-802
FES-801
0.00
0.80
6.29
0.0
41.5
0.013
0.58%
34
33.3
36
51.04
8.38
738.80
738.60
745.58
3.53
HDPE
Y1-851
DI-802
0.09
0.80
6.29
0.5
0.9
0.013
0.94%
53
7.2
8
1.17
3.77
741.50
741.00
744.50
2.29
HDPE
OCS-801
FES-800
0.00
0.85
6.29
0.0
48.9
0.013
0.50%
4-4
36.0
36
47.21
8.08
736.00
735.78
743.50
4.25
HDPE
AMENITY PIPE NETWORK
YI-856
YI-855
0.03
0.80
6.29
0.1
0.3
0.013
4.29%
35
3.B
8
2.51
4.31
744.5C
743.D�:
749.50
4.29
-: PE
YI-855
ST7
0.08
0.80
6.29
0.4
0.7
0.013
100%
0
2.8
8
12.12
15.97
743.00
742.93
749.50
5.79
HDPE

Rivercross
JOB NO.: 18-001
BY: udp
DATE:
05.30.19
P.M.: Ibr
REVISED:
08.03.20
Urban Design Partners
1318-E6 Central Avenue
Charlotte, NC 28205
Storm Drainage Design Data
STRUCTURE I❑
DRAINAGE
AREA
RUNOFF
C 1
_
PIPE
_
512E
(Inches)
VELOCITY
ACTUAL
INVERT ELEV.
UPSTREAM I DOWNSTREAM
INV INV
OUT IN
COVER
UPSTREAM
PIPE
MATERIAL
UPSTREAM
UPSTREAM
DOWNSTREAM
(acres)
[inlet
(Cis)
Qpipe
(cfs)
n
SLOPE LENGTH
(%) (ft)
CAPACITY
VEL.
(fps)
RIM
ELEVATION
COVER
DEPTH
(FROM)
(TO)
(cfsy
S0900 - PIPE NETWORK
CB-902
CB-901
0.06
0.80
6.29
0.3
48.6
0.013
2.17% 58
30
60.54
14.31
740.00
738.75
751.55
8.76
RCP 111
C8-901
CB-900
0.04
0.80
6.29
0.2
48.8
0.013
2.23% 56
30
61.36
14.25
738.75
737.50
749.00
7.46
RCP III
CB-900
FS-9001
0.21
0.80
6.29
1.0
49.8
0.013
2.90% 35
30
69.99
15.97
734.00
733.00
747.93
11.14
I RCP III
FS-9001
HW-9000
0.21
0.80
6.29
1.0
50.9
0.013
1.02% 25
36
67.49
10.88
730.25
730.00
739.50
5.92
RCP III
I
FS-9001
ST-9
0.00
0.80
6.29
0.0
11.1
0.013
0.013
0.013
4.92% 10
18
23.37
12.69
730.50
730.00
739.50
7.29
RCP 111
HOPE
HDPF
ST-9
BF-9
0.00
0.80
6.29
0.0
1.0
0.7296 8
12
3.02
3.27
729.36
729.30
739.00
8.54
BF-9
I HW-9002
0.00
0.80
6.29
. 0.0
1.0
0.5596 ' 9
12
2.65
3.00
728.00
727.95
736.50
7.40

RIPRAP
CALCULATIONS

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
0::::11.
1,:
j
outlet w • Do + Laf I
diameter(Do) r
w ter � 0.5Dp �I-� � a .I � p' ��
La —01
iiiWilik
Ntk.%1(\ 7q ":"": - E + .. 'Ie.:. .., ' :::',14 ' a 4._
ergs"a ' . i 1. , A
t�\ _ ir�u ii ��+rr+ill iJJJI..._0 4 0'-.
..::::.:
3, HI . : Inifillil:..:.. . .,\,<<:f_/. . :grad• _
.„:1 11111 N 1 U ::11 1111 7 i-. . jI.i!!Ijc - e s-- : i1 i^.i..?Q (III .. ..I ._..... . ■ 1 11111 ►21�./I1� 43
, 1 I 1 I 1)I I OrAlf:401 Pro t 1:4.. i' S
.. ... .. .. . .. .. .. .,; ill:,, - Y iarefAir '�� N
ii
1
._. 4 1 ',• r•213 *AdiraIPPAI •a-regillaillOr . _
•
1 v = 1s
vertu •. .!Tfl
3 5 10 20 50 100 200 500 1000
Discharge(t131sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe(lowing full,minimum tailwater condition(Tw<0.5 diameter),
FES-200:
Q = 21.0 cfs
da = 24" = 2'
3d, = 6'
La = 13'
w = 15'
v = 8.5fps
Rev.1213 d,„ = 0.6' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
0 :---...T.
j
Outlet w . Do + f I
diameter(Do) I :
1-a w ter 0.5Dp �� . . a I. pØ44,
. ...,,,,
,,,,, 7, _:_,,,,: _ E . • ... . .. .
./,
..,__.
,,,..„„cp6o _ ,._ .... ..,,..., . . , .
I . i „ 40,. . A i, .•
ergs"a 1 1. r•
r� aps •j
t�'� _ ir�u �0 �+rill..-� . . ..::::.:
-.
4 r ..... e 0 0 Ad., Ado.a Am.l 1 I1.Ikll. .1'
-.h ,0,,,Ars
ek
„.. 11,, .:::: .: __:_. 1,1, . 0.....,, _, ,, ,,,,,,,,,
liffilquit.,_-_,:: .4_ ,,,064,,...0.,,r,
.„:,11111IN I . " MI- t
multi on- '�.
`.
.. .... mint11tl ow. . .. r .. i , .7ifit ~•"� 3
#! .. *13 b!7.:1' .------
. .. , .. fr • ' 4 .ate. or Fes.;
.iist ,,\71:roir
}v 1v = 15 .. -. .....
tt' •'. s 'Ij M rr
W - r
0
3 5 10 20 50 100 200 500 1000
Discharge(t131sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe(lowing full,minimum tailwater condition(Tw<0.5 diameter).
FES-2000:
Q = 18.3 cfs
do = 24" = 2'
3d, = 6'
La = 13'
w = 15'
v = 8.3fps
Rev.11'93 d„ = 0.6' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
0 �---...T.
j
Outlet Y + La 9, 1 i
Rine N
diameter(Do) r
k 4 �'
i water c 0.5D0 • ;.1: : _/p
k,v...91. 60 • :. .• ..•.c.„.:. . , - Ill . . , 'AV. .1141 i, .• -
Ve-
41 ....._._____ --- .,___--_ a 4. , a1!1i 'i l.. - .P- a
0 • . 411041iir ', -
i I I ' - • ■ rill I ,, , • ' ,�0011
it IIp 1 1 111111 - —_±_. :'\ u11I 1'-.i,... i ��
?U ........Ilk ... .. Una�i�__.r_'r li !..._..... ji
I I..III 11 . , ., .. 111 3
ii
- k . : .p,
_ . -'"�',-�� :_ : i IFIIBhII
il•' 1 • Y r-� � a
00101F417 Afor-.c.): : c.E4
.;.......... . ... 4. _ _ I . .•,01rir b
" ' � -
} 1 s
r7.__lir.40la-v1411r 1j11•i"t''.
v= tti •.
I I 0
3 5 10 20 50 100 200 500 1000
Discharge(ft31sec)
Curves may riot be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe(lowing full,minimum tailwater condition(Tw<0.5 diameter).
FES-300:
Q = 35.6 cfs
da = 30" = 2.5'
3d, = 7.5'
La = 16'
w = 18.5'
v = 9.2 fps
Rev.11'93 d„ = 0.7' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
::c,::::if �---...T. joutlet • De + La i : •diameter(Do) : 0
La w ter 0.5Dp �I I Ø440
P6 H :. ,!,I'. :. -i-?_ !IIIll a j
Gt � 0 I f �.0
rr e r
tl� l _ 5 �1 rri I .. ::
41 .. . � e i, a il.lI HII. .1'
-00,10
.,„,
3
4
iI 1 ,, , _ ■ i i . ,._, I- - ,of, .a� 1 . .lisp.I. ._. . .:.:.
Fima.--. - PP" "..., .- . ,,ii i. ,.. .. ...i i .
.41111*,04'.'-' —
Atir,:drote.
a
[ . ._
:.!UIIH
dig
eL
;'e ,:: 1 .' , a .sue �',. .; .::. : 2
,,,.
,, ,25
Pirr.. --,'-.
\� 1 ... .-.i.-..
, 1 s
'. 74-157--.11...-illialffil 1
3 5 10 20 50 100 200 500 1000
Discharge(t131sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full,minimum tailwater condition(Tw<0.5 diameter).
HW-3000:
Q = 30.2 cfs
da = 30" = 2.5'
3d, = 7.5'
La = 16'
w = 18.5'
v = 8.1 fps
ReF.1213 d„ = 0.7' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
1,:c,:::::11. 1------- .
j
Outlet w • Do + La1 I
•
diameter(Do) I • r
La w ter 0.5Dp �I a I. pØ44,
. . A�
ergs.% 1 1. r r� aps •i
t�'� _ ir�u 1 . 100,:ivr. �1 �+rill I ..::::.:
41 IlIRHU:] ..... -� e 04,,E ,l Am.f I I1IHtoi. .1
. .....
. . ,,,,,,F0
.„, .I■. 1
1 ,, ,. ..1 III!71-. . .: ;9 _ e ,-ly 1^.i..JHHLIHk IIIIII r ` I .. . rol,i orup,
® 3�: .. . r
. . _ .. . so ifillirl,". .v
HIHIfi
, . . i
a ,._
.. - :lied 0� - ... ... ...... . d
lli
• „ = s _ � ��
f. 10/04101
1. . , �E; .�imr�■ •
v� 10
v = 5 :ram!��
0
3 5 10 20 50 100 200 500 1000
Discharge(t131sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full,minimum tailwater condition(Tw<0.5 diameter),
FES-400:
Q = 18.5 cfs
do = 24" = 2'
3d, = 6'
La = 13'
w = 15'
v = 10 fps
Rev.11'93 d,0 = 0.6' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
:::::IT -i---- . .
Outlet w . Do + f I
diameter(Do) r ii
� w ter � 0.5Dp ��-� � --a I �--p' � ,
,,. . . A�
ill
,.0.1:41,40:1
' r d
Ve.
,c ' 54'':.+,.: ��-. .. +�: ....-...--a � '•J•�i�r. +".1+ . _
40 , C _ d : � , .� , a1.1! 11Z1 .P a
' . 1 • 1 ,..!' ..� -
Tt.- i-: I . I Es, •,•. . didil !. .. ' : OF FiTi
eiP
,,11,•,..,- 4 1'7!111, --i. , . -•• .-1-'::::9:,,,,,,--;-;-2--P" . lisp./ ,.._•,.. il_00.4211:
, _ . . , 5. .0 .. . . ,,..f.-- .1 L.,... a N 1 mil : ,--., . 4. 3
' :1T7 .____),--1-"--- 2 '.'' ' .' . .. ,.. ... . Aid" kik"
. "- "MO, 1140Er ''
N�.�. ': .-. . - - .. ..III _ .. -r'�
.. .i +f #!I . b
pr
. - td.
1 1111 ____, ._
oi /401Pir a.
- ' / '-'''' . . . :v:-:20 ...iiipriiirdidillte. ASimpreill..? ' .. .... ... . . -..1, i.,. tr,C)
y _ 1_ �1.1
•
I [ 0
3 5 10 20 50 100 200 500 1000
Discharge(t131sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe(lowing full,minimum tailwater condition(Tw<0.5 diameter).
FES-4000:
Q = 3.7 cfs
da = 18" = 1.5'
3d, =4.5'
La = 11'
w = 12.5'
v = 5.8fps
Rev.11'93 d,„ = 0.3' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
1,:c,:::::11. -i---- . .
j
Outlet w . De + La i I
a I �u-, . - rdimeter(Do)
La a . p' r
wter 0.5D0 I 4
. .
di
" . ...,:',10110 •
t P� b0 1 I I �.tk -
e(4%G ; lili '• jr.
Fey' .i
....
!:.,.. ':!.:- . : : .! : '
41 IlIRHU:] ..... _� e"gi Iv,'' aa��r 1 I�IHkII. } . ...P
giu
3. MIIflhiiHIIIIUUH... , - �� ���
20 } „± # �� -± _ .:....: .POflflPig w:i ' ��
�' grafrAl 3
-gplil
. .. . : .. . . . 1
, „
..id . , 1 is •: . Y__ ,�
3. " ."1 1 �1... Apr g,
. . : . - E ... : ::.
. i : , .. . ..
.f
... ... i.
Aim 2„, „I_ • ,::,_
. . : - : . • , . . _ : ! , : -. : : 1 - -:-: :.::
. 1y.;. Af...ow •,. ...... .. . .frr..r7,.:::::.: : co
il
: : — - - :v 7-.5
. _ - d
rair Aiiir ' py .- ...-. .. .- .... ..7:-: - ii
y 16 .1. lagetrill@mi --0°P--iffWall ..,
y - s
I L l ;
3 5 10 20 50 100 200 500 1000
Discharge(tt31sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe(lowing full,minimum tailwater condition(Tw<0.5 diameter).
HW-450:
Q = 5.2 cfs
da = 18" = 1.5'
3d, =4.5'
La = 10'
w = 11.5'
v = 5.2 fps
Rev.11'93 d,„ = 0.3' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
/.c!::=IIT j
Outlet w . De + 1 I
pipe I I N
diameter(Do) : r 0
ff ;ler
i water 0.5ga :I-:;1 : of
ii,
Rpt �q _ .: : '. ._' r ilium I ! f s,
O N d 0i
t'c
��in i 1J
." sr IN.gow }
a ' lei ! 1 ,
'iiir ,.. j; - a
' . 1 POW r : . ....l , ....,A :
004,0,4
011,
„:,..
: !Immo; -,;;,._-• µ �� „Jr
,
. .- . .. . , , . . ,, .11 i all:: i ...,: pr,4414,,,:if ,
,, . -- 1-• - i : .01,7,..5.4
y = 15 _ �
v la ., .---'7-e. . .. -. -- .--- -
- i - 0
3 5 10 20 50 100 200 500 1000
Discharge(ft3lsec)
Curves may riot be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full,minimum tailwater condition(T„r<0.5 diameter)
FES-4500:
Q = 13.6 cfs
da = 24" = 2'
3d, = 6'
La = 13'
w = 15'
v = 7.5 fps
Rev.1213 d„ = 0.6' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
10::::IT �--- T. joutlet w . pe + La ; f i
Rine Ndiameter r
La Zfri
Dili • ' ff
f �'
iiiriaii water 0.500 . . ,I-:, : -:,_fi4 .e r
...,. .
6 ocs�° 1, 1- r , f or,�`' A
5It i .+..ICI. rr
t i lilt I. : : .:. . . '. ' ', rvillif sc-#10- Algil 1011 i. 1111-.1. :. , VI ';, ..„-'0..
. i .. .l ,w.--- F
4? : , 212111:11Hruiti:.:L. .. .-------7-- ' 6 -4"11'-'r . A‘1' ' II. - .tb - ill 4
--1 1 • • . Nil BM 1111111: .I. : '5:',1 0 lir'
1 . . 4 0 )
• • • 0' Atli
!. : .. . • : iii111111111•:•}.. ..d' '_-. ..11111.11j1 : : 4 iiiillqink ,._-_1: ,-,-5:40 ,o;Areri.vi
• MOM ensemuniowe',- PrAiriv:_,,, -,...., ill ' _ - mi a III sip : , ,, , iffrirlit.:ow 3
. . 111.4.1 it I---- '- 2 • 011.52- --''' Or- ... , .11itrA4,7‘iiiiii
- Air:iff.ov'-''-'
en
-HIV!I :41A• N
iis .., •.•• !..I1 . . v �' - ��' 2 [I]
_...,040.. A.Ir-iipiiir:4'1.v .4001r.b* Pre . . .::......:'IT.: .Q-
. . , .2° *.doilllialrilg011ispili.(005r
veto ., . .
i ] ..'. •
3 5 10 20 50 100 200 500 1000
Discharge 0ft31sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe(lowing full,minimum tailwater condition(Tw<0.5 diameter)
FES-500:
Q = 38.3 cfs
da = 36" = 3'
3d, = 9'
La = 22'
w = 25'
v = 8.7fps
Rev.11'93 d,, = 0.7' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
1,:c,:::::11. :------ .
j
Outlet w . De + La9:3f I
diameter(Do) I • r r
La w ter 0.5Dp �I a 'I. Ø44
ergs"a I I. r di
aps e •j
4110.1
kl\r"\``‘ 111111M1•,I !:•,.. '.:: I ....;,0950r.,,-d,-,, 1:. :,
I ma 1pi 1 �l ± cii s .� �`
lIII=rlrniliil N 1 11 II -
. ..I..._....: mPOflIflPi II111 . , 3
1 1 truli smiling•IIHI it �/+al'�,~ - _ 1 - I .. ' '�l
Illl i!11111111111111 iI1 } /� :: y'
10, ' IP ,. ,p.
,�,
_�. -._. . . ��_ ` - 2 v)
.47411
.. - .. - . foe. . . . ' O
,,y a_.... pr y'' ;., .. ....}. .:
y 5 �. I1� _ Ill . _
3 5 10 20 50 100 200 500 1000
Discharge(t131sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe(lowing full,minimum tailwater condition(Tw<0.5 diameter),
HW-500:
Q = 9.1 cfs
da = 18" = 1.5'
3d, =4.5'
La = 10'
w = 11.5'
v = 7.8fps
ReF.1213 d,„ = 0.55' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
0 �---...T.
j
Outlet y • Do + La 9, f . : : l
diameter(Do) La I :
wter 0.5D0 �I I. - �--p' �r
. .:. • FAQ
k..2,.;k.0 7P -:;'::: -. t + . lig:: . -.....: . :,:ititill • k_i___
err G ' O . A o.. .... .
41
11C
•
glillE
•
tl° l _ 5 ro rrl I } . ::: :
41 .... e i, a Of I ■Ikl. 1...Mr. '' died5 . . 0-- to
r,,,,o:,. .1.� i - iOhii1Ii < .!flIflH
V
y .r - - .. Ili l f --;.------ - :.i _ °Ill r: ''il .. 1- -I :.:i ! .: . . _ .. -- J
ire-
of _ ,r
I co
.;.......... ___.....________-_ _ _ _ _ I y -.is ..dieirOTildPv - b
-: - ::"-:-:::- ;: 1: : : ',100110- 400rAtierjA Q
j = 15 = _ ' :ui— : 4 :
. : . . - 7:117iiiiiiiiiiiiiiiiriiiiiiii '. 41.•'..
1 . [ ,1 :
v ' 5 11.1111.111 I 0
3 5 10 20 50 100 200 500 1000
Discharge(t131sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full,minimum tailwater condition(Tw<0.5 diameter},
FES-620:
Q = 33.8 cfs
da= 24" = 2'
3d, = 6'
La = 20'
w = 22'
v = 13.2 fps
Rev.11'93 d„ = 0.95' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
j
Outlet w . Do + f I
pipe i I N
diameter(Do) r ji
La mow{ Dili ' ,
k 4
i water c 0.500 :`: :,_�
ilieliti
;14 : d-%111
t-NW'I\ r . ' . '' i: 1 i . I 724..1 Iferl: .. 1:. .40::: :
‘,/j\r‘ . .. Hum i : ::::: . : . - 1 : .•oirovr,r-,;1;-_, . ..1 :: .: :
Ho. 1i1
} Ili._ _ . .E'I H 4�, ; 1 PI.O�Oii_•q,Mu4i.1Il•. ;ii. , IIflIuHIIIIUUH ,,,\. _f" wg Ai _ -
I . ,... ;000,14.4j ,
1 . ... .-•- BM : - • We....ifilierel i • • At•Iii 5
ir . .„,_..._;,,,.-.•,-..r," p7 ,„ . - 114404'.''
:i :, _Ill f .1111111:: 1 : .1...orielp1".. .. : Sa)
1.. ... ......'. { V _2y ..., .._ . .- Q_
.-.-...- - . .. .. d
7•400Pr'. '.. . •
10 �.'
. I f . l 0
3 5 10 20 50 100 200 500 1000
Discharge(ft31sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe(lowing full,minimum tailwater condition(Tw<0.5 diameter).
HW-650:
Q = 29.2 cfs
da = 30" = 2.5'
3d, = 7.5'
La = 16'
w = 18.5'
v = 9.0fps
Rev.11'93 d„ = 0.7' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
0 �---...T.
j
Outlet w . Do + f • I
diameter(Do) I :
La w ter 0.5Dp �` a I. , p' A,
otk.0 7P -: :: -'. I- +. . rimy:: .
h.oip� . :.:� ,+�., .-. f -I- ! ! ... ;-h,. �
06 \N ',::1 111 y.. . .!:. II 1; INF407 ••• b %.. ,
OK".r-,;1;-
ar s ;04Pi � all.11 !ill'_,
ii tll: _ ; H. -4- a
3 } i' : : 401rAgO
' 1IUIuPIiIIUUH . •\d i.F•".- oidritl _ plitii
-
1 -. I• {IN: f111 7 ; III“�•_ + !HHHIHL..,., „ , ilififi),1
�.i� 445
ill �
- 1-;-'5i/Fil di
iff It fri
,'4' .' ,r
' -I -1. — -... ir '.. _'-.- izz' - " frAr...07 ,.. „Of
.1/4,. . N,
, " u • _ ...__2 v.)
. a
._._ . - V p ,N1 -- .. _... .. Lo
•
,- = is = _..�.I " ' '
, iiv tti _ .�
0
3 5 10 20 50 100 200 500 1000
Discharge(t131sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe(lowing full,minimum tailwater condition(Tw<0.5 diameter).
FES-800:
Q = 48.9 cfs
do = 36" = 3'
3d, = 9'
La = 20'
w = 23'
v = 8.2 fps
Rev.11'93 d„ = 0.75' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
0 �---...T.
j
Outlet W • Do + La f : l
•
diameter(Do) I • r
La w ter 0.5D0 �` a .14 , 4.' �,
del 7o -.. .. _ E . . • 'i d ,--
ip� ,+I., .-: 1~ g ... ; .y am
06 \'‘ ', :Ill:.::' -:.. .'! - II A; INF41:14r/: .. b '''`• '
.
, �: �! l I !: , .-?ar a e ar a
,tto
• P0.10r.
s It ::.:. -
. : ,. •..•
. : 4 rim
3 is — . . no . • i • . :..;.. . '•,\,N -•••?.'•4'..-. • . 4110411/A .' ' . 0:40
_ 1411 quip, E-..i.:: 4400,114-ige.
1 - • .„IN: .•111 71-II •.... .rial
.,,-- toror- . ari r.:. :. . - i :
..
,,.g-.4.'.
' , JI11I1I
II i Y_ „ ,� .r
IIi • - ,..
1. ---- .. .. !! Nbir r t o .Io
. • • . ._ _ PI ..,,. - . . 2 05
-
::: J ' . Agaell - . .1 ,. .
. . . . i . . '' . 1 11 • • • :ffrigle.: ,,, adloript, ,
I . 4 ffriTiiieb*
Y •:-- .400iiirer, . .400efore ' fr ,:.:.1._:.1::'...._::. . it
•,,,) a_,III
. . . . .v, =.....100.p.. _olio._ inimillillir
v = 5 Illitiill II 0
3 5 10 20 50 100 200 500 1000
Discharge(tt31sec)
Curves may not be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full,minimum tailwater condition(Tw<0.5 diameter).
FES-801:
Q = 41.5 cfs
da = 36" = 3'
3dQ = 9'
Le = 20'
w = 23'
v = 8.2 fps
Rev.11'93 d„ = 0.75' 8.06.3

Figure 8.06a: Design of outlet protection from a round pipe flowing full, minimum
tailwater condition (Tw<8.5 diameter)
0 �---...T.
j
Outlet Y + La 9, f : l
diameter(Do) I :4/111
La w ter 0.5D0 �` LI
I.• , R.Ø44A�
kl'\r‘\ : .girli011pillir• -•1.- . .. :: .: :
Pirg•Pr. : . .. . 4 634,,IirS
3 } I1 : IIflIuHIIIIUUH .: .�. �
11111 ■ ■ :■11 :.' u it ii µ 55 ,�� I
• •.ram_, ..1I; 1I • _ Y14,deft
. lijilil
rt - •'C', 2 N
I
''s -4,0100pr—a"Tillir . 4,17- :. ': : . ...-1 ::::. .' cE.—
v7tu ., s
. I . . I
3 5 10 20 50 100 200 500 1000
Discharge(t131sec)
Curves may riot be extrapolated.
Figure 8.06a Design of outlet protection protection from a round pipe flowing full,minimum tailwater condition(Tw<0.5 diameter).
HW-7000:
Q = 35.9 cfs
do = 36" = 3'
3do = 9'
Le = 20'
w = 23'
v = 7.8fps
Rev.11'93 d„ = 0.75' 8.06.3

STORMWATER CONTROL
MEASURE CALCULATIONS

DRAINAGE
BASIN #1

Rivercross
JOB NO.: 18-001
DATE: 12.20.18
BY:
P.M.
Urban Design Partners
1318-E6 Central Avenue
Charlotte, NC 28205
REVISED: 08.03.20
Preliminary Calculations - Basin #1
INTRODUCTION:
SUMMARY
Drainage basin #1 includes townhome lots 1-13 in Phase 1A, a portion of Waterway Drive and the Duke Power
ROW. A pipe network system routes runoff to sand filter dry pond #1 which treats the water quality volume.
DRAINAGE AREAS:
(see drainage area map SW-3.0)
Predeveloped Drainage Area
5.76 acres
Postdeveloped Drainage Area
5.76 acres
SOIL TYPES:
(see soils map)
Area (ac) Area (%)
Soil Type
Hydrologic Soil Group
5.76
100%
B
Total
5.76
100%
CURVE NUMBER:
Predeveloped CN
Cover Type Area (ac) °No CN Wtd. CN
Wooded
2.88
50%
55
27.50
Grass
2.88
50%
61
30.50
Total
5.76
58.00
Composite CN
Use CN = 58
Postdeveloped CN
Cover Type Area (ac) % CN Wtd. CN
Impervious
0.73
13%
98
12.38
Grass
5.03
87%
61
53.30
Total
5.76
65.67
Composite CN
Use CN = 66

Rivercross
JOB NO.: 18-001
BY:
udp
DATE: 12.20.18
P.M..
Ibt
Urban Design Partners
1318-E6 Central Avenue
Charlotte, NC 28205
REVISED: 08.03.20
Preliminary Calculations - Basin #1
HYDROLOGIC CALCULATIONS
Drainage area (DA)
Cuve Number (CN)
Modified Curve Number (CN)
Time of Concentration
Impervious Percentage
Pre -developed
5.76 ac.
58
n/a
0.33 hr.
0%
WATER QUALITY VOLUME (1 ")
Volume must be released over a period of 2-5 days
Using the runoff volume calculations in the "Simple Method" :
Rv = 0.05 + .009 (I)
Rv= 0.16 in/in
WQv = (Design rainfall) (Rv) (Drainage Area)
WQv = 1 " rainfall x Rv in/in x 1/12 in/ft x Da =
WQv =
0.079 ac-ft
3,421 ft3
0.16 in
75% WQv =
0.059 ac-ft
2,565 ft3
0.123 in
MODIFIED CURVE NUMBER
CNm= 1000/{10+5P+10WQv-10(WQvA2+1.25WovP)A0.5}
P= rainfall, in inches (use1.0 inches) = 1.00
WQv= water quality volume, in inches = 0.12
CNm 82
CHANNEL PROTECTION VOLUME
Q= (P-0.2S)A21(P+0.8S)
Q= accumulated runoff volume, inches
P= accumulated rainfall (potential maximum runoff), inches
S= potential maximum soil retention, inches = 1000/CN-10 =
CN= SCS curve number
Q= 0.36 cfs
Compute Watershed Runoff
CPv= 0.172 ac-ft
7,490 cu. Ft
50% CPv =
Channel Protection Volume Release Rate (1yr, 24 hr storm)
1.5 day
36 hour
Release= 0.058 cfs
Post -developed
5.76 ac
66
82
0.08 hr.
13%
2.58 in
5.15 in
0.086 ac-ft
3,745 cu. Ft

Rivercross
JOB NO.: 18-001
BY: udp
DATE: 12.20.18
P.M.: Ibt
Urban Design Partners
1318-E6 Central Avenue
Charlotte, NC 28205
REVISED: 08.03.20
Impervious Calculations - Basin #1
Existing Impervious
Asphalt:
0 sf
Buildings:
0 sf
Concrete:
0 sf
Total Impervious Area:
0 sf
0.00 ac.
Drainage Area:
5.76
Impervious Percentage:
096
Proposed Impervious
Asphalt:
14,510 sf
Buildings:
15,130 sf
Concrete:
2,035 sf
Total Impervious Area:
31,675 sf
0.73 ac.
Drainage Area:
5.76
Impervious Percentage:
13%

Rivercross
OB NO.: 18-001
DATE: 12.20.18
REVISED: 08.03.20
BY: udp
P.M.: Ibt
Urban Design Partners
1318-E6 Central Avenue
Charlotte, NC 28205
Sand -Filter Design - Basin #1
Sand Filter Design Requirements
Design Method
Design Method
Detention Time
Filter Bed Depth
Underdrain System Thickness
Hydrologic Calculations
Drainage area to pond (Da)=
Cuve Number (CN)
Adjusted Curve Number (CN)
Time of Concentration
Impervious Percentage
Determine Suface Area to Treat WQv
Surface Area based on Darcy's Equation
Af= (WQv)(df)/((k)(h+d)(t))
Af= surface area of ponding area (sq ft)
WQv= water quality control volume
d= filter bed depth
k= coefficient of permeability of filter media
h= average height of water above filter bed (ft)
t= design filter bed drain time (days)
Af= 262 sf
Determine Dimensions of Sand Bed
Length= 26.0 ft
Width= 20.3 ft (triangular)
Area= 264 sf
TSS
2.0 days
2.5 ft
1.0 ft
Pre -developed
5.76 ac.
58
n/a
0.33 hr.
0%
2,565 cf
2.5 ft
3.5 ft/day
1ft
2.00 day
Post -developed
5.76 ac
66
82
0.08 hr.
13%
24" max for WQ storm event

Rivercross
JOB NO.: 18-001
BY: udp
DATE: 12.20.18
P.M.: Ibt
REVISED: 08.03.20
Urban Design Partners
1318-E6 Central Avenue
Charlotte, NC 28205
SandFilter Design - Basin #1
Stage/Storage Table
Elevation
(msl)
Area
Volume
Forebay
(sf
Main Pond
(sf)
Total
(sf)
Total
(ac)
Forebay
(cu-ft)
Main Pond
(cu-ft)
Total
(cu-ft)
Total
(ac-ft)
760.5
0
264
264
0.006
0
0
0
0.000
761
606
529 i
1,135
0.026
0
194
194
0.004
762
914
879
1,793
0.041
754
890
1,644
0.038
763
1,279
1,284 I
2,563
0.059
1,844
1,964
3,809
_
0.087
764
1,700
1,745
3,445
0.079
3,327
3,471
6,799
0.156
765
4,516
0.104
-
-
10,763
0.247
766
5,345
0.123
-
-
15,683
0.360
Stage/Discharge Table
Q= Af(k)(h+d)/(d)
Af= surface area of ponding area (sq ft)
d= filter bed depth
k= coefficient of permeability of filter media
h= average height of water above filter bed (ft)
Elevation
(msl°
Height
(ft)
Fow
(cf/day)
Flow
(cfs)
760.5
0 0
0.000
761.5
1
1,293
0.015
762.5
2
1,663
0.019
763.5
3
2,032
0.024
764.5
4
2,401
0.028
765.5
5
2,771
0.032
766
5.5 2.956
0.034
Peak Attenuation
264 sf
2.5 ft
3.5 ft/day
Forebay Welr
Elevation = 763.0
Q= 3.33LhA3/2
Q= 2 yr. storm runoff
L= weir length
h= elevation over weir
L= Q/(3.33 x IA3/2)
25.33 cfs
L ft
1.00 ft
Weir Length
I 7.6 ft (10' min)
Design
Storm
Peak Flow (cfs)
Peak Flow
Controlled?
i1NSE
Pre Post Routed
1-year
0.49
4.14
0.25
yes
763.13
10-year
6.27
17.87
4.92
yes
765.09
100-year
16.57
37.33
35.37
no
765.83
Top of dam elevation:
Top of outlet structure elevation:
WQv Water Surface Elevation:
Sand Bed Elevation:
766.00
765.15
762.21
760.50
WQv Release Rate (1-inch storm)
WQv (required) =
WQv (actual) _
Release Rate =
2,565 cf
2,387 cf
2.125 days
51 hour
0.013 cfs
(Refer to HydroCAD 1-inch routing table)

Rivercross
JOB NO.: 18-001
BY: udp
DATE: 12.20.18
P.M.: Ibt
Urban Design Partners
1318-E6 Central Avenue
Charlotte, NC 28205
REVISED: 08.03.20
Anti -Flotation Device Calculations
Calculations Given Data
Standard Footing Assumptions
Buoyant Weight of Concrete
87.6 Ibslft^3
1. Footing base to be 1 ft. wider than structure
Weight of Water
62.4 Ibs/ftA3
on all sides.
Safety Factor (S.F.)
1.25
2. Footing depth to be a minimum of 8 inches in depth.
Equations used:
Outlet Structure Weight, W(s) = 4(w + t) x t x h x 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
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)
Outlet Structure #1
w
Structure Dimensions
Object Weights
Height of structure, h =
7 ft.
Outlet Structure Weight, W(s) =
5637 Ibs
Structure wall thickness, t =
6 in.
Displaced Water Weight, W(w) =
8923.2 Ibs
Outlet box inside dimension, w =
4 ft.
Req'd Base Weight, W(b) =
5517 Ibs
Footln •_
Required Footing Volume, V(f) =
63 cf
Standard Footing Length, L =
7.00 ft.
Provided Footing Volume, V(f) =
74 cf
Standard Footing Width, W =
7.00 ft.
Footing Check
okay
Minimum Footing Depth, D =
1.50 ft.
Footing Size to be used:
Length = 7.00 ft.
Width = 7.00 ft. Outlet
Depth = 1.50 ft.
Structure #1

HYDR0CAD
ROUTINGS

1-INCH
ROUTING

•
yist CNm
AD
1 Sand Filter
Subcat Reach 'on. Iti Routing Diagram for 1
Prepared by{enter your company name here), Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

1 Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 1C: 1 Post CNm
Runoff = 1.48 cfs @ 2.99 hrs, Volume= 2,387 cf, Depth= 0.11"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 6-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 5.760 82 Modified CN
5.760 100.00°/% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, post To
Subcatchment 1 C: 1 Post CNm
Hydrograph
11 0 Runoff
I+-+eI
Type II
6-hr
1-inch Rainfall=1.00"
1_ Runoff Area=5.760 ac
13 Runoff Volume=2,387 cf
LL Runoff Depth=0.11"
Tc=5.0 min
CN=82
0 i4%///f///////////f//f//////////////////////////////////////////////////////f//f//f//f////////
0 5 10 15 20 25 30 35 40 45 50 55 60 65 TD 75 80 85 90 95 100 105 110 115 120
Time (hours)

1 Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 1 D: 1 Sand Filter
Inflow Area = 250,906 sf, 0.00% Impervious, Inflow Depth = 0.11" for 1-inch event
Inflow = 1.48 cfs @ 2.99 hrs, Volume= 2,387 cf
Outflow = 0.02 cfs @ 6.11 hrs, Volume= 2,387 cf, Atten= 99%, Lag= 186.9 min
Primary = 0.02 cfs @ 6.11 hrs, Volume= 2,387 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=762.21' @ 6.11 hrs Surf.Area= 1,952 sf Storage= 2,201 cf
Flood Elev= 766.00' Surf.Area= 5,345 sf Storage= 15,907 cf
Plug-Flow detention time= 1,286.1 min calculated for 2,387 cf(100% of inflow)
Center-of-Mass det. time= 1,287.0 min ( 1,518.4 -231.3 )
Volume Invert Avail.Storage Storage Description
#1 760.50' 15,907 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
760.50 264 0 0
761.00 1,135 350 350
762.00 1,793 1,464 1,814
763.00 2,563 2,178 3,992
764.00 3,445 3,004 6,996
765.00 4,516 3,981 10,976
766.00 5,345 4,931 15,907
Device Routing Invert Outlet Devices
#1 Primary 758.00' 24.0" Round Culvert L= 32.7' Ke= 0.500
Inlet/Outlet Invert= 758.00'!757.75' S= 0.0076 '1' Cc= 0.900
n= 0.013, Flow Area= 3.14 sf
#2 Device 1 760.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50
Disch. (cfs) 0.000 0.015 0.019 0.024 0.028 0.032 0.034
#3 Device 1 763.00' 18.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 765.15' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
Primary OutFlow Max=0.02 cfs @ 6.11 hrs HW=762.21' (Free Discharge)
L-1=Culvert (Passes 0.02 cfs of 27.09 cfs potential flow)
Ai_
2=Sand Bed Exfiltration (Custom Controls 0.02 cfs)
3=Low Flow Orifice ( Controls 0.00 cfs)
4=Grate Top ( Controls 0.00 cfs)

1 Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond 1 D: 1 Sand Filter
Hyd rag raph
■Inflow
. I�.48 crs I 0 Primary I
Inflow Area=250,906 sf
Peak Elegy=762.21
Storage=2,201 cf
1-
U
V
t
LL
n /J////////////// ._ /////%/%/%%////////////////////////////////////////////////%
. . . . . . . . . . . . . . . .
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)

1 Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Hydrograph for Pond 1 D: 1 Sand Filter
Time Inflow Storage Elevation Primary
(hours) (cfs) (cubic-feet) (feet) (cfs)
0.00 0.00 0 760.50 0.00
3.00 1.47 377 761.02 0.01
6.00 0.09 2,184 762.20 0.02
9.00 0.00 2,019 762.11 0.02
12.00 0.00 1,833 762.01 0.02
15.00 0.00 1,651 761.91 0.02
18.00 0.00 1,474 761.80 0.02
21.00 0.00 1,301 761.70 0.02
24.00 0.00 1,133 761.59 0.02
27.00 0.00 969 761.48 0.01
30.00 0.00 819 761.37 0.01
33.00 0.00 686 761.27 0.01
36.00 0.00 568 761.18 0.01
39.00 0.00 465 761.10 0.01
42.00 0.00 374 761.02 0.01
45.00 0.00 295 760.95 0.01
48.00 0.00 228 760.88 0.01
51.00 0.00 172 760.82 0.00
54.00 0.00 125 760.76 0.00
57.00 0.00 88 760.70 0.00
60.00 0.00 60 760.65 0.00
63.00 0.00 39 760.61 0.00
66.00 0.00 25 760.57 0.00
69.00 0.00 15 760.55 0.00
72.00 0.00 9 760.53 0.00
75.00 0.00 5 760.52 0.00
78.00 0.00 3 760.51 0.00
81.00 0.00 2 760.51 0.00
84.00 0.00 1 760.50 0.00
87.00 0.00 1 760.50 0.00
90.00 0.00 0 760.50 0.00
93.00 0.00 0 760.50 0.00
96.00 0.00 0 760.50 0.00
99.00 0.00 0 760.50 0.00
102.00 0.00 0 760.50 0.00
105.00 0.00 0 760.50 0.00
108.00 0.00 0 760.50 0.00
111.00 0.00 0 760.50 0.00
114.00 0.00 0 760.50 0.00
117.00 0.00 0 760.50 0.00
120.00 0.00 0 760.50 0.00

1 -YEAR
ROUTING

< IA>
K< IB >
Predeveloped I Postdevel ped
ID
Sand Filter
Subcat Reach 'on. Routing Diagram for 1
Prepared by{enter your company name here), Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

1 Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment IA: I Predeveloped
Runoff = 0.49 cfs @ 12.23 hrs, Volume= 4,446 cf, Depth= 0.21"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 2.880 55 Wooded
* 2.880 61 Grass
5.760 58 Weighted Average
5.760 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment IA: 1 Predeveloped
Hydrograph
•Runoff
0 5" I 149�l
ype II 24-hr
0-4517' 1-yr Rainfall=2.80"
°4J Runoff Area=5.760 ac
035 Runoff Volume=4,446 cf
0.31 Runoff Depth=0.21"
0-251 Tc=20.0 min
D2J CN=58
0-15.
0.1�
0 05
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 9D 95 100 105 110 115 120
Time (hours)

1 Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 1 B: 'I Postdeveloped
Runoff = 4.14 cfs @ 11.98 hrs, Volume= 9,461 cf, Depth= 0.45"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 0.730 98 Impervious
* 5.030 61 Grass
5.760 66 Weighted Average
5.030 87.33% Pervious Area
0.730 12.67% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 1 B: 1 Postdeveloped
Hydrograph
■Runoff
14.14 cis
41 Type II 2, -hr
1-yr Rainfall=2.-:0"
RunoffAre =5.76' ac
Runoff Volum =9,46 cf
Runoff Depth=0., 5"
LL 2—Z-10 Tc=5.0 in
CN 66
1-
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)

1 Type !I 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 1 D: 1 Sand Filter
Inflow Area = 250,906 sf, 12.67% Impervious, Inflow Depth = 0.45" for 1-yr event
Inflow = 4.14 cfs @ 11.98 hrs, Volume= 9,461 cf
Outflow = 0.25 cfs @ 13.71 hrs, Volume= 9,457 cf, Atten= 94%, Lag= 103.6 min
Primary = 0.25 cfs @ 13.71 hrs, Volume= 9,457 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=763.13' @ 13.71 hrs Surf.Area=2,678 sf Storage=4,333 cf
Flood Elev= 766.00' Surf.Area= 5,345 sf Storage= 15,907 cf
Plug-Flow detention time= 1,122.3 min calculated for 9,457 cf(100% of inflow)
Center-of-Mass det. time= 1,122.0 min ( 2,023.9 - 901.9 )
Volume Invert Avail.Storage Storage Description
#1 760.50' 15,907 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
760.50 264 0 0
761.00 1,135 350 350
762.00 1,793 1,464 1,814
763.00 2,563 2,178 3,992
764.00 3,445 3,004 6,996
765.00 4,516 3,981 10,976
766.00 5,345 4,931 15,907
Device Routing Invert Outlet Devices
#1 Primary 758.00' 24.0" Round Culvert L= 32.7' Ke= 0.500
Inlet/Outlet Invert= 758.00'!757.75' S= 0.0076 '!' Cc= 0.900
n= 0.013, Flow Area= 3.14 sf
#2 Device 1 760.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50
Disch. (cfs) 0.000 0.015 0.019 0.024 0.028 0.032 0.034
#3 Device 1 763.00' 18.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 765.15' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
Primary OutFlow Max=0.25 cfs @ 13.71 hrs HW=763.13' (Free Discharge)
L-1=Culvert (Passes 0.25 cfs of 30.74 cfs potential flow)
2=Sand Bed Exfiltration (Custom Controls 0.02 cfs)
Ai_
3=Low Flow Orifice (Orifice Controls 0.23 cfs @ 1.16 fps)
4=Grate Top ( Controls 0.00 cfs)

1 Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond 1 D: 1 Sand Filter
Hydrograph
■Inflow
14.14 ds I 0 Primary I
Inflow Area=250,906 sf
4- Peak Elegy=763.13'
Storage=4,333 cf
3_
a ,
L 2
�1
n /// %/%%////////////////////////////////////////////////////////////////////////////
. . . . . . . . . . . . . . . . . . . . .
0 5 10 15 20 25 30 35 40 45 50 55 80 85 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

10-YEAR
ROUTING

1 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 1 B: 'I Postdeveloped
Runoff = 17.87 cfs @ 11.97 hrs, Volume= 35,272 cf, Depth= 1.69"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type 1124-hr 10-yr Rainfall=4.94"
Area (ac) CN Description
* 0.730 98 Impervious
* 5.030 61 Grass
5.760 66 Weighted Average
5.030 87.33% Pervious Area
0.730 12.67% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 1 B: 1 Postdeveloped
Hydrograph
2D� ■Runoff
19=
19= I 17�I
17 Type II 2 -hr
16 V / 10-yr Rainfall=4.•4"
"
14= Runoff Area=5.76' ac
13=r Runoff Volume=35,27' cf
7,7 12=
11.. Runoff Depth=1. •9"
1D=�
0 9v� Tc=5.0 in
LL a
CN 66
7
5'"
4=,
2. r i
01
0 5 10 15 20 25 30 35 40 45 50 55 66 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

1 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 'I A: 'I Predeveloped
Runoff = 6.27 cfs @ 12.15 hrs, Volume= 23,751 cf, Depth= 1.14"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 10-yr Rainfall=4.94"
Area (ac) CN Description
* 2.880 55 Wooded
* 2.880 61 Grass
5.760 58 Weighted Average
5.760 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 1A: 1 Predeveloped
Hydrograph
7y
•Runoff
67 cfsI
61 Type II 24-h r
10-yr Rainfall=4.94"
51 ♦ Runoff Area=5.76O ac
♦ Runoff Volume=23,751 cf
N 41 ♦ Run6ff Depth=1.14"
j Tc= O.Omin
LL
CN-58
1/
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)

1 Type !I 24-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 1 D: 1 Sand Filter
Inflow Area = 250,906 sf, 12.67% Impervious, Inflow Depth = 1.69" for 10-yr event
Inflow = 17.87 cfs @ 11.97 hrs, Volume= 35,272 cf
Outflow = 4.92 cfs @ 12.09 hrs, Volume= 35,267 cf, Atten= 72%, Lag= 7.6 min
Primary = 4.92 cfs @ 12.09 hrs, Volume= 35,267 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=765.09' @ 12.09 hrs Surf.Area=4,587 sf Storage= 11,363 cf
Flood Elev= 766.00' Surf.Area= 5,345 sf Storage= 15,907 cf
Plug-Flow detention time= 318.5 min calculated for 35,258 cf(100% of inflow)
Center-of-Mass det. time= 319.8 min ( 1,174.4 - 854.6 )
Volume Invert Avail.Storage Storage Description
#1 760.50' 15,907 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
760.50 264 0 0
761.00 1,135 350 350
762.00 1,793 1,464 1,814
763.00 2,563 2,178 3,992
764.00 3,445 3,004 6,996
765.00 4,516 3,981 10,976
766.00 5,345 4,931 15,907
Device Routing Invert Outlet Devices
#1 Primary 758.00' 24.0" Round Culvert L= 32.7' Ke= 0.500
Inlet/Outlet Invert= 758.00'!757.75' S= 0.0076 '!' Cc= 0.900
n= 0.013, Flow Area= 3.14 sf
#2 Device 1 760.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50
Disch. (cfs) 0.000 0.015 0.019 0.024 0.028 0.032 0.034
#3 Device 1 763.00' 18.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 765.15' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
Primary OutFlow Max=4.91 cfs @ 12.09 hrs HW=765.08' (Free Discharge)
L-1=Culvert (Passes 4.91 cfs of 37.31 cfs potential flow)
2=Sand Bed Exfiltration (Custom Controls 0.03 cfs)
Ai_
3=Low Flow Orifice (Orifice Controls 4.88 cfs @ 6.51 fps)
4=Grate Top ( Controls 0.00 cfs)

1 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond 1 D: 1 Sand Filter
Hydrograph
20. / ■Inflow
19= "rids ❑Primary
18V Inflow Are =250,906 sf
17- / Peak Elev=765.09'
15 Storage=11,363 cf
14-
13',
12-/
11:
10=9 /
/
a
0
LL -/
7=/
6i 4_92 crs
•
3 /-
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)

100-YEAR
ROUTING

1 Type 1124-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 'I A: 'I Predeveloped
Runoff = 16.57 cfs @ 12.14 hrs, Volume= 55,993 cf, Depth= 2.68"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 100-yr Rainfall=7.39"
Area (ac) CN Description
* 2.880 55 Wooded
* 2.880 61 Grass
5.760 58 Weighted Average
5.760 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 1A: 1 Predeveloped
Hydrograph
///
18= •Runoff
17✓ Ii657c
161
Type II 24-hr
1
14]"r 100-yr Rainfall=7.39"
13= Runoff Area=5.760 ac
12= Runoff Volume=55,993 cf
13 10= Runoff Depth=2.68"
3 9= Tc-20.0 min
LL of
7=r / CN=5
s;r
2=
11
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)

1 Type 1124-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 1 B: 'I Postdeveloped
Runoff = 37.33 cfs @ 11.96 hrs, Volume= 73,465 cf, Depth= 3.51"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 100-yr Rainfall=7.39"
Area (ac) CN Description
* 0.730 98 Impervious
* 5.030 61 Grass
5.760 66 Weighted Average
5.030 87.33% Pervious Area
0.730 12.67% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 1 B: 'I Postdeveloped
Hydrograph
■Runoff
40',
381I� u:I
36' Type Il 24-hr
341 100-yr Rainfall-7.39"
32',r
301 Runoff Area=5.766 ac
2 a
261 Runoff Volu me=73,465 cf
2224 Runoff Depth=3.51"
20= Tc-5.0 min
LL 18 j
16' CN=66
14
12',�
10
a- /
41/ 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)

1 Type I!24-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 1 D: 1 Sand Filter
Inflow Area = 250,906 sf, 12.67% Impervious, Inflow Depth = 3.51" for 100-yr event
Inflow = 37.33 cfs @ 11.96 hrs, Volume= 73,465 cf
Outflow = 35.37 cfs @ 11.99 hrs, Volume= 73,460 cf, Atten= 5%, Lag= 1.4 min
Primary = 35.37 cfs @ 11.99 hrs, Volume= 73,460 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=765.83' @ 11.99 hrs Surf.Area= 5,207 sf Storage= 15,027 cf
Flood Elev= 766.00' Surf.Area= 5,345 sf Storage= 15,907 cf
Plug-Flow detention time= 162.4 min calculated for 73,460 cf(100% of inflow)
Center-of-Mass det. time= 162.3 min ( 995.2 - 832.9 )
Volume Invert Avail.Storage Storage Description
#1 760.50' 15,907 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
760.50 264 0 0
761.00 1,135 350 350
762.00 1,793 1,464 1,814
763.00 2,563 2,178 3,992
764.00 3,445 3,004 6,996
765.00 4,516 3,981 10,976
766.00 5,345 4,931 15,907
Device Routing Invert Outlet Devices
#1 Primary 758.00' 24.0" Round Culvert L= 32.7' Ke= 0.500
Inlet/Outlet Invert= 758.00'!757.75' S= 0.0076 '1' Cc= 0.900
n= 0.013, Flow Area= 3.14 sf
#2 Device 1 760.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50
Disch. (cfs) 0.000 0.015 0.019 0.024 0.028 0.032 0.034
#3 Device 1 763.00' 18.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 765.15' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
Primary OutFlow Max=34.67 cfs @ 11.99 hrs HW=765.82' (Free Discharge)
L-1=Culvert (Passes 34.67 cfs of 39.51 cfs potential flow)
2=Sand Bed Exfiltration (Custom Controls 0.03 cfs)
Ai_
3=Low Flow Orifice (Orifice Controls 5.79 cfs @ 7.72 fps)
4=Grate Top (Weir Controls 28.85 cfs @ 2.68 fps)

1 Type 1124-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond 1 D: 1 Sand Filter
Hydrograph
/ ■Inflow
I4D= / I3733`rs I 0 Primary
3a-✓ If Inflow Area=250,906 sf
36
34 toy
Peak E_Iev=765.83'
32
3Di Storage=15,027 cf
2a
26-
m 24--' /
0 2Di
a 181
16i ,
14= f
12 /
4 ' /
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)

DRAINAGE
BASIN #2

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #2
INTRODUCTION:
SUMMARY
Drainage basin#2 includes townhome lots 1-12 &35-45 in Phase 1A, a portion of Waterway Drive and Hazel
Way.A pipe network system routes runoff to sand filter dry pond#2 which treats the water quality volume.
DRAINAGE AREAS: (see drainage area map SW-3.0)
Predeveloped Drainage Area 2.77 acres
Postdeveloped Drainage Area 2.77 acres
SOIL TYPES: (see soils map)
Area(ac) Area(%) Soil Type Hydrologic Soil Group
2.77 100% B
Total 2.77 100%
CURVE NUMBER:
Predeveloped CN
Cover Type Area(ac) CN Wtd. CN
Wooded 1.38 50% 55 27.50
Grass 1.38 50% 61 30.50
Total 2.77 58.00
Composite CN Use CN = 58
Postdeveloped CN
Cover Type Area(ac) °/n CN Wtd. CN
Impervious 1.87 67% 98 66.12
Grass 0.90 33% 61 19.84
Total 2.77 85.97
'Composite CN Use CN = 86

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #2
HYDROLOGIC CALCULATIONS
Pre-developed Post-developed
Drainage area(DA) 2.77 ac. 2.77 ac
Cuve Number(CN) 58 86
Modified Curve Number(CN) n/a 94
Time of Concentration 0.33 hr. 0.08 hr.
Impervious Percentage 0% 67%
WATER QUALITY VOLUME (1°)
Volume must be released over a period of 2-5 days
Using the runoff volume calculations in the "Simple Method" :
Rv= 0.05+ .009(I)
Rv= 0.66 in/in
WQv=(Design rainfall)(Rv)(Drainage Area)
WQv= 1" rainfall x Rv in/in x 1/12 in/ft x Da=
WQv= 0.152 ac-ft 75% WQv= 0.114 ac-ft
6,607 ft3 4,955 ft3
0.66 in 0.49 in
MODIFIED CURVE NUMBER
CNm= 1000/(10+5P+10W Qv-10(WQ02+1.25WQvP)^0.5}
P= rainfall, in inches(use1.0 inches)= 1.00
WQv= water quality volume, in inches= 0.49
CNm 93.8
CHANNEL PROTECTION VOLUME
Q= (P-0.2S)^21(P+0.8S)
Q= accumulated runoff volume, inches
P= accumulated rainfall(potential maximum runoff), inches 2.58 in
S= potential maximum soil retention, inches= 1000/CN-10 = 1.63 in
CN= SCS curve number
Q= 1.31 cfs
Compute Watershed Runoff
CPv= 0.302 ac-ft 50% CPv= 0.151 ac-ft
13,159 cu. Ft 6,580 cu. Ft
Channel Protection Volume Release Rate(1yr, 24 hr storm)
1.5 day
36 hour
Release= 0.102 cfs

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: lbt Charlotte, NC 28205
REVISED: 08.03.20 Impervious Calculations - Basin #2
Existing Impervious
Asphalt: sf
Buildings: sf
Concrete: sf
Total Impervious Area: 0 sf
0.00 ac.
Drainage Area: 2.77
Impervious Percentage: 0%
Proposed Impervious
Asphalt: 24,900 sf
Buildings: 36,415 sf
Concrete: 20,075 sf
Total Impervious Area: 81,390 sf
1.87 ac.
Drainage Area: 2.77
Impervious Percentage: 67%

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Sand Filter Design - Basin #2
Sand Filter Design Requirements
Design Method
Design Method TSS
Detention Time 2.0 days
Filter Bed Depth 2.5 ft
Underdrain System Thickness 1.0 ft
Hydrologic Calculations
Pre-developed Post-developed
Drainage area to pond(Da)— 2.77 ac. 2.77 ac
Cuve Number(CN) 58 86
Adjusted Curve Number(CN) n/a 94
Time of Concentration 0.33 hr. 0.08 hr.
Impervious Percentage 0% 67%
Determine Suface Area to Treat WQv
Surface Area based on Darcy's Equation
Af= (WQv)(df)/((k)(h+d)(t)}
Af= surface area of ponding area(sq ft)
WQv= water quality control volume 4,955 of
d= filter bed depth 2.5 ft
k= coefficient of permeability of filter media 3.5 ft/day
h= average height of water above filter bed(ft) 1 ft 24" max for WO storm event
t= design filter bed drain time(days) 2.00 day
Af= 506 sf
Determine Dimensions
Length= 55 ft
Width= 9.4 ft
Area= 518 sf

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Sand Filter Design - Basin #2
Stage/Storage Table
Elevation Area Volume
Forebay Main Pond Total Total Forebay Main Pond Total Total
(ms1) (sf (sf) (st) (ac) (cu-ft) (cu-ft) (cu-ft) (ac-ft)
,752 0 518 518 0.012 0 0 0 0.000
753 1,914 1,256 I 3,170 0.073 0 859 859 0.020
—
754 2,489 1,887 4,376 0.100 2,193 2,419 4,612 0.106
755 3,119 2,574 I 5,693 0.131 4,988 i 4,838 9,626 0.221
756 7,130 0.164 16,018 0.368
757 8,450 0.194 23,791 0.546
—
Stage/Discharge Table
Q= Af(k)(h+d)1(d)
Af= surface area of ponding area(sq ft) 518 sf
d= filter bed depth 2.5 ft
k= coefficient of permeability of filter media 3.5 ft/day
h= average height of water above filter bed (ft)
Elevation Height Fow Flow Forebay Weir
(msl) (ft) (cf/day) (cfs) Elevation= 754.5
752 0 0 0.000 Q= 3.33Lh^312
753 1 2,538 0.029 Q= 2 yr.storm runoff 12.18 cfs
754 2 3,263 0.038 L= weir length L ft
755 3 3,989 0.046 h= elevation over weir 0.50 ft
756 4 4,714 0.055 L= Q/(3.33 x 1^312)
757 5 5,439 0.063 Weir Length 10 ft(10' min)
Peak Attenuation WQv Release Rate(1-inch storm)
.-
Design Peak Flow(cfs) Peak Flow WQv(required) = 4.955 cf
Storm Pre Post Routed Controlled? WSE WQv(actual)= 5,065 cf
1-year 0.24 7.57 0.19 yes 754.96 2.5 days
10-year 3.01 16.66 2.95 yes 758.03 60 hour
100-year 7.97 27.13 19.32 no 756.94 Release Rate= 0.023 cfs
Top of dam elevation: 757.00 (Refer to HydroCA❑1-inch routing table)
Top of outlet structure elevation: 756.50
WQv Water Surface Elevation: 753.77
Sand Bed Elevation: 752.00

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Anti-Flotation Device Calculations
Calculations Given Data Standard Footing Assumptions
Buoyant Weight of Concrete 87.6 Ibs/ft^3 1. Footing base to be 1 ft. wider than structure
Weight of Water 62.4 Ibs/ft^3 on all sides.
Safety Factor(S.F.) 1.25 2. Footing depth to be a minimum of 8 inches in depth.
Equations used:
Outlet Structure Weight,W(s)= 4(w+t)x t x h x W(bc)
where, w= outlet box inside dimension,ft.
Displaced Water Weight,W(w)= 4 x(w+2t)x W(w)x h t= structure wall thickness,ft.
h= height of structure,ft.
Required Base Weight,W(b)= (W(w)x S.F.)-W(s) W(bc)= buoyant weight of concrete, Ibs/ft^3
W(w)= weight of water,Ibs/ft^3
Required Footing Volume,V(f)= W(b)/W{bc) S.F.= safety factor
•u e ru ure '
Structure Dimensions Object Weights
Height of structure, h= 7 ft. Outlet Structure Weight,Ms) = 5519 lbs
Structure wall thickness,t= 6 in. Displaced Water Weight,W(w)= 8736 lbs
Outlet box inside dimension,w= 4 ft. R-.'d Base Weight,W W . = 5401 lbs
Footing. Size
Required Footing Volume,V(f)= 62 cf _ Standard Footing Length, L= 7.00 ft.
Provided Footing Volume,V(f)= 74 cf Standard Footing Width,W= 7.00 ft.
Footing Check okay Minimum Footing Depth, ❑= 1.50 ft.
Footing Size to be used: Length= 7.00 ft. i
Width = 7.00 ft. Outlet Structure #2
Depth = 1.50 ft.

HYDROCAD
ROUTINGS

1 - INCH
ROUTING

•
ost CNm
/2N)
2 Sand Filter
Subcat Reach 'on■ Link Routing Diagram for 2
Prepared by{enter your company name here), Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

2 Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 2C: 2 Post CNm
Runoff = 3.70 cfs @ 2.96 hrs, Volume= 5,065 cf, Depth= 0.50"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 6-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 2.770 94 Modified CN
2.770 100.00°/% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, post To
Subcatchment 2C: 2 Post CNm
Hydrograph
44 0 Runoff
I 3.70 cis I
'� } Type II
6-hr
3 • 1-inch Rainfall=1.00"
Runoff Area=2.770 ac
Runoff Volume=5,065 f
LL
Runoff Depth=0.50"
Tc=5.0 min
1 ✓ CN=94
n i�/////////////////f//f//f//////////////////////////////////////////////////////f//f//f////////
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)

2 Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 2D: 2 Sand Filter
Inflow Area = 120,661 sf, 0.00% Impervious, Inflow Depth = 0.50" for 1-inch event
Inflow = 3.70 cfs @ 2.96 hrs, Volume= 5,065 cf
Outflow = 0.04 cfs @ 6.09 hrs, Volume= 5,065 cf, Atten= 99%, Lag= 187.3 min
Primary = 0.04 cfs @ 6.09 hrs, Volume= 5,065 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=753.77' @ 6.09 hrs Surf.Area=4,102 sf Storage=4,654 cf
Flood Elev= 757.00' Surf.Area= 8,450 sf Storage=24,853 cf
Plug-Flow detention time= 1,343.8 min calculated for 5,064 cf(100% of inflow)
Center-of-Mass det. time= 1,344.7 min ( 1,550.1 -205.4 )
Volume Invert Avail.Storage Storage Description
#1 752.00' 24,853 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
752.00 518 0 0
753.00 3,170 1,844 1,844
754.00 4,376 3,773 5,617
755.00 5,693 5,035 10,652
756.00 7,130 6,412 17,063
757.00 8,450 7,790 24,853
Device Routing Invert Outlet Devices
#1 Primary 749.50' 18.0" Round Culvert L= 104.4' Ke= 0.500
Inlet/Outlet Invert= 749.50'1748.00' S= 0.0144 '1' Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1 752.00' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00
Disch. (cfs) 0.000 0.029 0.038 0.046 0.055 0.063
#3 Device 1 754.85' 15.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 756.50' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
Primary OutFlow Max=0.04 cfs @ 6.09 hrs HW=753.77' (Free Discharge)
L-1=Culvert (Passes 0.04 cfs of 15.88 cfs potential flow)
14
2=Sand Bed Exfiltration (Custom Controls 0.04 cfs)
3=Low Flow Orifice ( Controls 0.00 cfs)
=Grate Top ( Controls 0.00 cfs)

2 Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
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Pond 2D: 2 Sand Filter
Hydrograph
■Inflow
4 Ia-4o6'3I 0 Primary)
Inflow rea=12O,661 sf
P ak Elev=753.77'
to rag a=4,654 cf
V
g 2
IL '
1
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)

2 Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Hydrograph for Pond 2D: 2 Sand Filter
Time Inflow Storage Elevation Primary
(hours) (cfs) (cubic-feet) (feet) (cfs)
0.00 0.00 0 752.00 0.00
3.00 3.24 2,257 753.13 0.03
6.00 0.10 4,643 753.77 0.04
9.00 0.00 4,286 753.68 0.04
12.00 0.00 3,911 753.59 0.03
15.00 0.00 3,545 753.49 0.03
18.00 0.00 3,189 753.39 0.03
21.00 0.00 2,842 753.30 0.03
24.00 0.00 2,505 753.20 0.03
27.00 0.00 2,177 753.10 0.03
30.00 0.00 1,859 753.00 0.03
33.00 0.00 1,559 752.91 0.03
36.00 0.00 1,291 752.81 0.02
39.00 0.00 1,052 752.72 0.02
42.00 0.00 842 752.62 0.02
45.00 0.00 660 752.54 0.02
48.00 0.00 505 752.45 0.01
51.00 0.00 376 752.37 0.01
54.00 0.00 272 752.30 0.01
57.00 0.00 189 752.23 0.01
60.00 0.00 127 752.17 0.00
63.00 0.00 82 752.12 0.00
66.00 0.00 51 752.08 0.00
69.00 0.00 30 752.05 0.00
72.00 0.00 18 752.03 0.00
75.00 0.00 10 752.02 0.00
78.00 0.00 6 752.01 0.00
81.00 0.00 4 752.01 0.00
84.00 0.00 2 752.00 0.00
87.00 0.00 1 752.00 0.00
90.00 0.00 1 752.00 0.00
93.00 0.00 0 752.00 0.00
96.00 0.00 0 752.00 0.00
99.00 0.00 0 752.00 0.00
102.00 0.00 0 752.00 0.00
105.00 0.00 0 752.00 0.00
108.00 0.00 0 752.00 0.00
111.00 0.00 0 752.00 0.00
114.00 0.00 0 752.00 0.00
117.00 0.00 0 752.00 0.00
120.00 0.00 0 752.00 0.00

1 -YEAR
ROUTING

(2A>
< 2B >
2 Predeveloped 2 Postdev loped
AND
2 Sand Filter
Subcat Reach 'on. Routing Diagram for 2
Prepared by{enter your company name here), Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

2 Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 2A: 2 Predeveloped
Runoff = 0.24 cfs @a 12.23 hrs, Volume= 2,138 cf, Depth= 0.21"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 1.385 55 Wooded
* 1.385 61 Grass
2.770 58 Weighted Average
2.770 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 2A: 2 Predeveloped
Hydrograph
0.26j/ •Runoff
Trlaza�l
0.23✓ Type II 24-h r
0.22
0.21;y f 1-yr Rainfall=2.80"
[1.12 L
0- 9✓ / Runoff Area=2.770 ac
0.18; f /
o;�y__✓� Runoff Volume=2,138 cf
0:;4 Runoff Depth=0.21"
g 0-112/ % Tc=20.0 min
u 0 11
pit/
CN=58
0 D --_—�j
0 0.0.
0.03=r / 47
0.02 .'
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)

2 Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 26: 2 Postdeveloped
Runoff = 7.57 cfs @ 11.96 hrs, Volume= 15,002 cf, Depth= 1.49"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 1.868 98 Impervious
* 0.901 61 Grass
2.769 86 Weighted Average
0.901 32.54% Pervious Area
1.868 67.46% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 2B: 2 Postdeveloped
Hydrograph
■Runoff
8. 17.57 cfs
Type II 24-hr
717'
1-yr Rainfall=2.80"
Runoff Area=2.769 ac
5� Runoff Volume=15,002 cf
110 Runoff Depth=1.49"
4 Tc=5.0 min
IL
3 CN=86
2:
0
;17 ii
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)

2 Type II 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 2D: 2 Sand Filter
Inflow Area = 120,618 sf, 67.46% Impervious, Inflow Depth = 1.49" for 1-yr event
Inflow = 7.57 cfs @ 11.96 hrs, Volume= 15,002 cf
Outflow = 0.19 cfs @ 15.14 hrs, Volume= 14,949 cf, Atten= 98%, Lag= 190.8 min
Primary = 0.19 cfs @ 15.14 hrs, Volume= 14,949 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=754.96' @ 15.14 hrs Surf.Area= 5,636 sf Storage= 10,405 cf
Flood Elev= 757.00' Surf.Area= 8,450 sf Storage=24,853 cf
Plug-Flow detention time= 1,924.9 min calculated for 14,945 cf(100% of inflow)
Center-of-Mass det. time= 1,923.7 min ( 2,748.1 - 824.4 )
Volume Invert Avail.Storage Storage Description
#1 752.00' 24,853 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
752.00 518 0 0
753.00 3,170 1,844 1,844
754.00 4,376 3,773 5,617
755.00 5,693 5,035 10,652
756.00 7,130 6,412 17,063
757.00 8,450 7,790 24,853
Device Routing Invert Outlet Devices
#1 Primary 749.50' 18.0" Round Culvert L= 104.4' Ke= 0.500
Inlet/Outlet Invert= 749.50'1748.00' S= 0.0144 '1' Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1 752.00' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00
Disch. (cfs) 0.000 0.029 0.038 0.046 0.055 0.063
#3 Device 1 754.85' 15.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 756.50' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
Primary OutFlow Max=0.18 cfs @ 15.14 hrs HW=754.96' (Free Discharge)
L-1=Culvert (Passes 0.18 cfs of 17.94 cfs potential flow)
2=Sand Bed Exfiltration (Custom Controls 0.05 cfs)
14
3=Low Flow Orifice (Orifice Controls 0.14 cfs @ 1.05 fps)
=Grate Top ( Controls 0.00 cfs)

2 Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here) Printed 7/30/2020
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Pond 2D: 2 Sand Filter
Hydrograph
■Inflow
7ST ds ■Pnmaiy
Inflow Area=120,618 sf
7 Peak EIev=754.95'
6—�� Storage=10,405 cf
5 '
0 4
17/
2-
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)

10-YEAR
ROUTING

2 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 2A: 2 Predeveloped
Runoff = 3.01 cfs @ 12.15 hrs, Volume= 11,422 cf, Depth= 1.14"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 10-yr Rainfall=4.94"
Area (ac) CN Description
* 1.385 55 Wooded
* 1.385 61 Grass
2.770 58 Weighted Average
2.770 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 2A: 2 Predeveloped
Hydrograph
•Runoff
301irfs
Type II 24-hr
10-yr Rainfall=4.94"
Runoff Area=2.770 ac
e=11,422 cf
2—
Runoff Depth=1.14"
Tc=20.0 min
LL
CN=58
1y
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)

2 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 26: 2 Postdeveloped
Runoff = 16.66 cfs @ 11.96 hrs, Volume= 34,286 cf, Depth= 3.41"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 10-yr Rainfall=4.94"
Area (ac) CN Description
* 1.868 98 Impervious
* 0.901 61 Grass
2.769 86 Weighted Average
0.901 32.54% Pervious Area
1.868 67.46% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 2B: 2 Postdeveloped
Hydrograph
18=" ■Runoff
17✓ lsseds
16 Type II 24-hr
151 p 10-yr Rainfall=4.94"
14✓ Runoff Area=2.769 ac
13-
12 Runoff Volume=34,286 cf
11=
71 13 10 3-7 Runoff Depth=3.41"
Tc=5.0 min
0
u
° CN=86
E/
2✓ % r 1 I
i�i� iii /ill����rlf�������r����fr�l�������r
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)

2 Type II 24-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 2D: 2 Sand Filter
Inflow Area = 120,618 sf, 67.46% Impervious, Inflow Depth = 3.41" for 10-yr event
Inflow = 16.66 cfs @ 11.96 hrs, Volume= 34,286 cf
Outflow = 2.95 cfs @ 12.13 hrs, Volume= 34,227 cf, Atten= 82%, Lag= 10.1 min
Primary = 2.95 cfs @ 12.13 hrs, Volume= 34,227 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=756.03' @ 12.13 hrs Surf.Area=7,170 sf Storage= 17,279 cf
Flood Elev= 757.00' Surf.Area= 8,450 sf Storage=24,853 cf
Plug-Flow detention time= 888.4 min calculated for 34,227 cf(100% of inflow)
Center-of-Mass det. time= 887.3 min ( 1,688.2 - 800.9 )
Volume Invert Avail.Storage Storage Description
#1 752.00' 24,853 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
752.00 518 0 0
753.00 3,170 1,844 1,844
754.00 4,376 3,773 5,617
755.00 5,693 5,035 10,652
756.00 7,130 6,412 17,063
757.00 8,450 7,790 24,853
Device Routing Invert Outlet Devices
#1 Primary 749.50' 18.0" Round Culvert L= 104.4' Ke= 0.500
Inlet/Outlet Invert= 749.50'1748.00' S= 0.0144 '1' Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1 752.00' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00
Disch. (cfs) 0.000 0.029 0.038 0.046 0.055 0.063
#3 Device 1 754.85' 15.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 756.50' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
Primary OutFlow Max=2.95 cfs @ 12.13 hrs HW=756.03' (Free Discharge)
L-1=Culvert (Passes 2.95 cfs of 19.63 cfs potential flow)
2=Sand Bed Exfiltration (Custom Controls 0.06 cfs)
14
3=Low Flow Orifice (Orifice Controls 2.89 cfs @ 4.63 fps)
=Grate Top ( Controls 0.00 cfs)

2 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond 2D: 2 Sand Filter
Hydrograph
///// ■Inflow
19'. 11"6 cis I 0 Primary I
17= / Inflow Area=120,618 sf
16= /15 / Peak EIev=756.03'
_
14= , Storage=17,279 cf
13=
12i/
11' /
10-�//
0 /
LL a-
7
6: /
�
3'./
. % %%////////////////////////////////////////////////// / /
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)

100-YEAR
ROUTING

2 Type 1124-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 2A: 2 Predeveloped
Runoff = 7.97 cfs @ 12.14 hrs, Volume= 26,927 cf, Depth= 2.68"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 100-yr Rainfall=7.39"
Area (ac) CN Description
* 1.385 55 Wooded
* 1.385 61 Grass
2.770 58 Weighted Average
2.770 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 2A: 2 Predeveloped
Hydrograph
•Runoff
S� I7.97 cfs
Type II 24-hr
100-yr Rainfall=7.39"
8 f Runoff Area— .770 ac
Runoff Volume= 6,927 cf
1 Runoff Dep h=2.68"
.2 41Z Tc— 0.0 min
3 J CN=58
z1
11
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)

2 Type 1124-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 26: 2 Postdeveloped
Runoff = 27.13 cfs @ 11.96 hrs, Volume= 57,709 cf, Depth= 5.74"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 100-yr Rainfall=7.39"
Area (ac) CN Description
* 1.868 98 Impervious
* 0.901 61 Grass
2.769 86 Weighted Average
0.901 32.54% Pervious Area
1.868 67.46% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 2B: 2 Postdeveloped
Hydrograph
30, ■Runoff
294-/ 27.13,ds
26✓ Type II 24-hr
24- I '100- 4r Rainfall=7.39"
�� Runo Area=2.769 ac
20- , Runoff V• Iu me=57,709 cf
1 a=
16= / Run•ff Depth=5.74"
0 14- Tc=5.0 m ii n
LL 121Z CN=86
107
a=�
sf
4
27
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)

2 Type I!24-hr 100-yr Rainfal1=7.39"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 2D: 2 Sand Filter
Inflow Area = 120,618 sf, 67.46% Impervious, Inflow Depth = 5.74" for 100-yr event
Inflow = 27.13 cfs @ 11.96 hrs, Volume= 57,709 cf
Outflow = 19.32 cfs @ 12.02 hrs, Volume= 57,647 cf, Atten= 29%, Lag= 3.7 min
Primary = 19.32 cfs @ 12.02 hrs, Volume= 57,647 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=756.94' @ 12.02 hrs Surf.Area= 8,368 sf Storage= 24,333 cf
Flood Elev= 757.00' Surf.Area= 8,450 sf Storage=24,853 cf
Plug-Flow detention time= 554.2 min calculated for 57,647 cf(100% of inflow)
Center-of-Mass det. time= 553.5 min ( 1,339.8 - 786.3 )
Volume Invert Avail.Storage Storage Description
#1 752.00' 24,853 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
752.00 518 0 0
753.00 3,170 1,844 1,844
754.00 4,376 3,773 5,617
755.00 5,693 5,035 10,652
756.00 7,130 6,412 17,063
757.00 8,450 7,790 24,853
Device Routing Invert Outlet Devices
#1 Primary 749.50' 18.0" Round Culvert L= 104.4' Ke= 0.500
Inlet/Outlet Invert= 749.50'1748.00' S= 0.0144 '1' Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1 752.00' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00
Disch. (cfs) 0.000 0.029 0.038 0.046 0.055 0.063
#3 Device 1 754.85' 15.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 756.50' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
Primary OutFlow Max=18.91 cfs @ 12.02 hrs HW=756.93' (Free Discharge)
L-1=Culvert (Passes 18.91 cfs of 20.94 cfs potential flow)
2=Sand Bed Exfiltration (Custom Controls 0.06 cfs)
14
3=Low Flow Orifice (Orifice Controls 4.07 cfs @ 6.51 fps)
=Grate Top (Weir Controls 14.78 cfs @ 2.15 fps)

2 Type 1124-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond 2D: 2 Sand Filter
Hydrograph
■Inflow
3D- 127.13 cfs I ■Primary I
29 / Inflow Area=120,618 sf
26 /
�v
Peak EIev=756.94'
24i /
/ Storage4,333 cf
1932 ds
2D=
1a-
1s
0 14 /
12V1D:
a /
�4
D
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)

DRAINAGE
BASIN #3

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #3
INTRODUCTION:
SUMMARY
Drainage basin#3 includes townhome lots 46-56&76-85 in Phase 1 B,a portion of Waterway Drive and Ashton
Park Drive. A pipe network system routes runoff to sand filter dry pond#3 which treats the water quality
volume.
DRAINAGE AREAS: (see drainage area map SW-3.0)
Predeveloped Drainage Area 3.13 acres
Postdeveloped Drainage Area 3.13 acres
SOIL TYPES: (see soils map)
Area(ac) Area(%) Soil Type Hydrologic Soil Group
3.13 100% B
Total 3.13 100%
CURVE NUMBER:
Predeveloped CN
Cover Type Area(ac) CN Wtd. CN
Wooded 1.56 50% 55 27.50
Grass 1.56 50% 61 30.50
Total 3.13 58.00
Composite CN Use CN = 58
Postdeveloped CN
Cover Type Area(ac) % CN Wtd. CN
Impervious 1.92 61% 98 60.10
Grass 1.21 39% 61 23.59
Total 3.13 83.69
'Composite CN Use CN = 84

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #3
HYDROLOGIC CALCULATIONS
Pre-developed Post-developed
Drainage area(DA) 3.13 ac. 3.13 ac
Cuve Number(CN) 58 84
Modified Curve Number(CN) n/a 93
Time of Concentration 0.33 hr. 0.08 hr.
Impervious Percentage 0% 61%
WATER QUALITY VOLUME (1°)
Volume must be released over a period of 2-5 days
Using the runoff volume calculations in the "Simple Method" :
Rv= 0.05+ .009(I)
Rv= 0.60 in/in
WQv=(Design rainfall)(Rv)(Drainage Area)
WQv= 1" rainfall x Rv in/in x 1/12 in/ft x Da=
WQv= 0.157 ac-ft 75% WQv= 0.118 ac-ft
6,831 ft3 5,124 ft3
0.60 in 0.45 in
MODIFIED CURVE NUMBER
CNm= 1000/(10+5P+10W Qv-10(WQ02+1.25WQvP)^0.5}
P= rainfall, in inches(use1.0 inches)= 1.00
WQv= water quality volume, in inches= 0.45
CNm 93.0
CHANNEL PROTECTION VOLUME
Q= (P-0.2S)^21(P+0.8S)
Q= accumulated runoff volume, inches
P= accumulated rainfall(potential maximum runoff), inches 2.58 in
S= potential maximum soil retention, inches= 1000/CN-10 = 1.90 in
CN= SCS curve number
Q= 1.18 cfs
Compute Watershed Runoff
CPv= 0.307 ac-ft 50% CPv= 0.154 ac-ft
13,374 cu. Ft 6,687 cu. Ft
Channel Protection Volume Release Rate(1yr, 24 hr storm)
1.5 day
36 hour
Release= 0.103 cfs

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Hot Charlotte, NC 28205
REVISED: 08.03.20 Impervious Calculations - Basin #3
Existing Impervious
Asphalt: 0 sf
Buildings: 0 sf
Concrete: 0 sf
Total Impervious Area: 0 sf
0.00 ac.
Drainage Area: 3.13
Impervious Percentage: 0%
Proposed Impervious
Asphalt: 28,615 sf
Buildings: 35,055 sf
Concrete: 19,850 sf
Total Impervious Area: 83,520 sf
1.92 ac.
Drainage Area: 3.13
Impervious Percentage: 61%

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp _ 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: It Charlotte, NC 28205
REVISED: 08.03.20 Sand Filter Design - Basin #3
Sand Filter Design Requirements
Design Method
Design Method TSS
Detention Time 2.0 days
Filter Bed Depth 2.5 ft
Underdrain System Thickness 1.0 ft
Hydrologic Calculations
Pre-developed Post-developed
Drainage area to pond(Da)= 3.13 ac. 3.13 ac
Cuve Number(CN) 58 84
Adjusted Curve Number(CN) nla 93
Time of Concentration 0.33 hr. 0.08 hr.
Impervious Percentage 0% 61%
Determine Suface Area to Treat WQv
Surface Area based on Darcy's Equation
Af= (WQv)(df)1((k)(h+d)(t))
Af= surface area of ponding area(sq ft)
WQv= water quality control volume 5,124 cf
d= filter bed depth 2.5 ft
k= coefficient of permeability of filter media 3.5 ft/day
h= average height of water above filter bed(ft) 1 ft 24' max for WQ storm event
t= design filter bed drain time(days) 2.00 day
Af= 523 sf
Determine Dimensions
Length= 70.0 ft
Width= 7.5 ft
Area= 525 sf

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Sand Filter Design - Basin #3
Stage/Storage Table
Elevation Area Volume
Forebay Main Pond Total Total Forebay Main Pond Total Total
(msl) (sf (sf} (sf} (ac) (cu-ft) (cu-ft) (cu-ft) (ac-ft)
745.5 0 525 525 0.012 0 0 0 0.000
746 1,885 1,403 3,288 0.075 0 l 464 464 0.011
-
747 2,583 2,300 4,883 0.112 2,223 2,295 4,518 0.104
748 3,305 3,266 6,571 I 0.151 5,156 5,061 10,218 0.235
749 8,136 0.187 17,550 0.403
750 9,555 0.219 26,377 0.606
-
Stage/Discharge Table
Q= Af(k)(h+d}I(d)
Af= surface area of bonding area(sq ft) 525 sf
d= filter bed depth 2.5 ft
k= coefficient of permeability of filter media 3.5 ft/day
h= average height of water above filter bed(ft)
Elevation Height Fow Flow Forebay Weir
(msD (ft) (cf/day) (cis} Elevation= 747.0
745.5 0 0 0.000 Q= 3.33LhA312
746.5 1 2,573 0.030 Q= 2 yr.storm runoff 13.76 cfs
747.5 2 3,308 0.038 L= weir length L ft
748.5 3 4,043 0.047 h= elevation over weir 1.00 ft
749.5 4 4,778 0.055 L= 0/(3.33 x lA3/2)
750 4.5 5,145 0.060 Weir Length I 4.1 ft(10' min)
Peak Attenuation WQv Release Rate(1-inch storm)
Design Peak Flow(cfs) j Peak Flow WQv(required)= 5,124 cf
Storm • Pre Post Routed Controlled? WSE - WQv(actual)= 5,117 cf
1-year 0.27 7.81 0.10 yes 748.25 2.875 days
10-year 3.40 17.97 2.43 yes 749.08 69 hour
100-year 8.99 29.83 25.73 no 749.64 Release Rate= 0.021 cfs
Top of Dam Elevation: 750.00 (Refer to HydroCAD 1-inch routing table)
Emergency Spillway Elevation: 749.50
Top of outlet structure elevation: 749.10
WQv Water Surface Elevation: 746.94
Sand Bed Elevation: 745.50

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Anti-Flotation Device Calculations
Calculations Given Data Standard Footing Assumptions
Buoyant Weight of Concrete 87.6 Ibslft^3 1. Footing base to be 1 ft. wider than structure
Weight of Water 62.4 Ibslft^3 on all sides.
Safety Factor(S.F.) 1.25 2. Footing depth to be a minimum of 8 inches in depth.
Equations used:
Outlet Structure Weight,W(s)= 4(w+t)x t x h x W(bc)
where, w= outlet box inside dimension,ft.
Displaced Water Weight,W(w)= 4 x(w+2t)x W(w)x h t= structure wall thickness,ft.
h= height of structure,ft.
Required Base Weight,W(b)= (W(w)x S.F.)-W(s) W(bc)= buoyant weight of concrete, Ibslft^3
W(w)= weight of water,Ibs/ft^3
•
Required Footing Volume,V(f)= W(b)/W(bc) S.F.= safety factor
•u e ru ure
Structure Dimensions Object Weights
Height of structure, h = 6 ft. Outlet Structure Weight, W(s) = 4809 lbs
Structure wall thickness,t = 6 in. Displaced Water Weie,W(w)= 7612.8 lbs
Outlet box inside dimension, w= 4 ft. 'd Base Weight,W . = 4707 lbs
Footing Size
Required Footing Volume,V(t)= 54 cf Standard Footing Length, L= 7.00 ft.
Provided Footing Volume,V(f)= 74 cf - Standard Footing Width,W= 7.00 ft.
Footing Check okay Minimum Footing Depth, D= 1.50 ft.
Footing Size to be used: M Length= 7.00 ft. '
Width = 7.00 ft. Outlet Structure #3
Depth = 1.50 ft.

HYDROCAD
ROUTINGS

1 - INCH
ROUTING

•
3 P st CNm
/3N-2/
3 Sand Filter
Subcat Reach 'on. Routing Diagram for 3
Prepared by{enter your company name here), Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

3 Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 3C: 3 Post CNm
Runoff = 3.77 cfs @ 2.97 hrs, Volume= 5,117 cf, Depth= 0.45"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 6-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 3.130 93 Modified CN
3.130 100.00°/% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post To
Subcatchment 3C: 3 Post CNm
Hydrograph
■Runoff
4 3 77 c1a
r Type II
6-hr
3 1-inch Rainfall=1.00"
Runoff Area=3.130 ac
Runoff Volume=5,117 cf
LL 2 Runoff Depth=0.45"
Tc=5.0 min
/1 CN=93
0 /4��////////////////f//f//////////////////////////////////////////////////////f//f//f//f////////
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)

3 Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 3D: 3 Sand Filter
Inflow Area = 136,343 sf, 0.00% Impervious, Inflow Depth = 0.45" for 1-inch event
Inflow = 3.77 cfs @ 2.97 hrs, Volume= 5,117 cf
Outflow = 0.03 cfs @ 6.09 hrs, Volume= 5,117 cf, Atten= 99%, Lag= 187.6 min
Primary = 0.03 cfs @ 6.09 hrs, Volume= 5,117 cf
Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=746.94' @ 6.09 hrs Surf.Area=4,784 sf Storage=4,739 cf
Flood Elev= 750.00' Surf.Area= 9,555 sf Storage=26,965 cf
Plug-Flow detention time= 1,528.1 min calculated for 5,117 cf(100% of inflow)
Center-of-Mass det. time= 1,528.0 min ( 1,735.5 -207.5 )
Volume Invert Avail.Storage Storage Description
#1 745.50' 26,965 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
745.50 525 0 0
746.00 3,288 953 953
747.00 4,883 4,086 5,039
748.00 6,571 5,727 10,766
749.00 8,136 7,354 18,119
750.00 9,555 8,846 26,965
Device Routing Invert Outlet Devices
#1 Primary 743.00' 24.0" Round Culvert L=49.8' Ke= 0.500
Inlet/Outlet Invert= 743.00'!742.50' S= 0.0100 '!' Cc= 0.900
n= 0.013, Flow Area= 3.14 sf
#2 Device 1 745.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 4.50
Disch. (cfs) 0.000 0.030 0.038 0.047 0.055 0.060
#3 Device 1 748.20' 15.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 749.10' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
#5 Secondary 749.50' 15.0' long x 6.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.37 2.51 2.70 2.68 2.68 2.67 2.65 2.65 2.65
2.65 2.66 2.66 2.67 2.69 2.72 2.76 2.83

3 Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Primary OutFlow Max=0.03 cfs @ 6.09 hrs HW=746.94' (Free Discharge)
L Culvert (Passes 0.03 cfs of 25.93 cfs potential flow)
3=Sand Bed Exfiltration (Custom Controls 0.03 cfs)
—3=Low Flow Orifice ( Controls 0.00 cfs)
—4=Grate Top ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=745.50' (Free Discharge)
LS=Emergency Spillway ( Controls 0.00 cfs)
Pond 3D: 3 Sand Filter
Hydrograph
■Inflow
Outflow
any I
Inflow Area=136,343 sf o rco dory
4 Peak Elegy=746.94'
Storage=4,739 cf
3
-
U
O
LL
1
0.03 cfs
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)

3 Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Hydrograph for Pond 3D: 3 Sand Filter
Time Inflow Storage Elevation Outflow Primary Secondary
(hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs)
0.00 0.00 0 745.50 0.00 0.00 0.00
3.00 3.33 2,165 746.34 0.03 0.03 0.00
6.00 0.11 4,724 746.93 0.03 0.03 0.00
9.00 0.00 4,395 746.87 0.03 0.03 0.00
12.00 0.00 4,043 746.79 0.03 0.03 0.00
15.00 0.00 3,697 746.71 0.03 0.03 0.00
18.00 0.00 3,358 746.63 0.03 0.03 0.00
21.00 0.00 3,026 746.56 0.03 0.03 0.00
24.00 0.00 2,701 746.48 0.03 0.03 0.00
27.00 0.00 2,397 746.40 0.03 0.03 0.00
30.00 0.00 2,118 746.33 0.02 0.02 0.00
33.00 0.00 1,860 746.26 0.02 0.02 0.00
36.00 0.00 1,625 746.19 0.02 0.02 0.00
39.00 0.00 1,410 746.13 0.02 0.02 0.00
42.00 0.00 1,213 746.08 0.02 0.02 0.00
45.00 0.00 1,035 746.02 0.02 0.02 0.00
48.00 0.00 873 745.97 0.01 0.01 0.00
51.00 0.00 727 745.93 0.01 0.01 0.00
54.00 0.00 597 745.88 0.01 0.01 0.00
57.00 0.00 481 745.83 0.01 0.01 0.00
60.00 0.00 381 745.79 0.01 0.01 0.00
63.00 0.00 295 745.74 0.01 0.01 0.00
66.00 0.00 222 745.70 0.01 0.01 0.00
69.00 0.00 163 745.66 0.00 0.00 0.00
72.00 0.00 115 745.63 0.00 0.00 0.00
75.00 0.00 78 745.60 0.00 0.00 0.00
78.00 0.00 51 745.57 0.00 0.00 0.00
81.00 0.00 32 745.55 0.00 0.00 0.00
84.00 0.00 20 745.53 0.00 0.00 0.00
87.00 0.00 12 745.52 0.00 0.00 0.00
90.00 0.00 7 745.51 0.00 0.00 0.00
93.00 0.00 4 745.51 0.00 0.00 0.00
96.00 0.00 3 745.50 0.00 0.00 0.00
99.00 0.00 2 745.50 0.00 0.00 0.00
102.00 0.00 1 745.50 0.00 0.00 0.00
105.00 0.00 1 745.50 0.00 0.00 0.00
108.00 0.00 0 745.50 0.00 0.00 0.00
111.00 0.00 0 745.50 0.00 0.00 0.00
114.00 0.00 0 745.50 0.00 0.00 0.00
117.00 0.00 0 745.50 0.00 0.00 0.00
120.00 0.00 0 745.50 0.00 0.00 0.00

1 -YEAR
ROUTING

< 3A>
K< 3B >
3 Predeveloped 3 Postdevel ped
AND
3 Sand Filter
Subcat Reach 'on■ Link Routing Diagram for 3
Prepared by{enter your company name here), Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

3 Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 3A: 3 Predeveloped
Runoff = 0.27 cfs @a 12.23 hrs, Volume= 2,413 cf, Depth= 0.21"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 1.563 55 Wooded
* 1.563 61 Grass
3.126 58 Weighted Average
3.126 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 3A: 3 Predeveloped
Hydrograph
z
■Runoff
0.28i/ I L2T�I
0.261"/ Type II 24-h r
0.24 1-yr Rainfall=2.80"
022 Runoff Area=3.126 ac
0.2�
0.18 Runoff Volume=2,413 cf
0.161 % Runoff Depth=0.21"
° 014 Tc=20.0 min
II 0
011"/ / CN=58
008
0.04-
° O EN", r(, .,.:.. tfr��ff��tf��ff�r' �� l��� r rr,�f( ,r{frr�ff�,�frrr�ff�,�fr��ff�
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)

3 Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 36: 3 Postdeveloped
Runoff = 7.81 cfs @ 11.96 hrs, Volume= 15,377 cf, Depth= 1.35"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 1.920 98 Impervious
* 1.210 61 Grass
3.130 84 Weighted Average
1.210 38.66% Pervious Area
1.920 61.34% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 3B: 3 Postdeveloped
Hydrograph
/ ■Runoff
sJ 7.9,cra
Type II 24-hr
1-yr Rainfall=2.80"
6- i Runoff Area=3.138 ac
Runoff Volume=15,377 cf
N 51 Runoff Depth=1.35"
4- ' Tc=5.8 min
IL
3J CN=84
2-
1�
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)

3 Type II 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 3D: 3 Sand Filter
Inflow Area = 136,343 sf, 61.34% Impervious, Inflow Depth = 1.35" for 1-yr event
Inflow = 7.81 cfs @ 11.96 hrs, Volume= 15,377 cf
Outflow = 0.10 cfs @ 19.85 hrs, Volume= 14,500 cf, Atten= 99%, Lag=473.1 min
Primary = 0.10 cfs @ 19.85 hrs, Volume= 14,500 cf
Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=748.25' @ 19.85 hrs Surf.Area= 6,966 sf Storage= 12,476 cf
Flood Elev= 750.00' Surf.Area= 9,555 sf Storage=26,965 cf
Plug-Flow detention time= 2,544.4 min calculated for 14,496 cf(94% of inflow)
Center-of-Mass det. time= 2,513.5 min ( 3,345.2 - 831.7 )
Volume Invert Avail.Storage Storage Description
#1 745.50' 26,965 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
745.50 525 0 0
746.00 3,288 953 953
747.00 4,883 4,086 5,039
748.00 6,571 5,727 10,766
749.00 8,136 7,354 18,119
750.00 9,555 8,846 26,965
Device Routing Invert Outlet Devices
#1 Primary 743.00' 24.0" Round Culvert L=49.8' Ke= 0.500
Inlet!Outlet Invert= 743.00'!742.50' S= 0.0100 '!' Cc= 0.900
n= 0.013, Flow Area= 3.14 sf
#2 Device 1 745.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 4.50
Disch. (cfs) 0.000 0.030 0.038 0.047 0.055 0.060
#3 Device 1 748.20' 15.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 749.10' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
#5 Secondary 749.50' 15.0' long x 6.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.37 2.51 2.70 2.68 2.68 2.67 2.65 2.65 2.65
2.65 2.66 2.66 2.67 2.69 2.72 2.76 2.83

3 Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here} Printed 7/30/2020
HydreCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Primary OutFlow Max=0.09 cfs @ 19.85 hrs HW=748.25' (Free Discharge)
t Culvert (Passes 0.09 cfs of 31.19 cfs potential flow)
—2=Sand Bed Exfiltration (Custom Controls 0.04 cfs)
—3=Low Flow Orifice (Orifice Controls 0.05 cfs @ 0.74 fps)
—4=Grate Top ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=745.50' (Free Discharge)
L5=Emergency Spillway ( Controls 0.00 cfs)
Pond 3D: 3 Sand Filter
Hydrograph
•Inflow
7E7 cfs •Outflow
Inflow Area=136,343 sf :Lam,,,
8: Peak Elev=748.25T
T. Storage=12,476 cf
6:
u 5_
o 4
LL
3
2/ °
U.10 cfs
1 ',
// ri®/////
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)

10-YEAR
ROUTING

3 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 3A: 3 Predeveloped
Runoff = 3.40 cfs @ 12.15 hrs, Volume= 12,890 cf, Depth= 1.14"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 10-yr Rainfall=4.94"
Area (ac) CN Description
* 1.563 55 Wooded
* 1.563 61 Grass
3.126 58 Weighted Average
3.126 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 3A: 3 Predeveloped
Hydrograph
0 Runoff
I3AD cisI
r Type II 24-hr
31 10-yr Rainfall=4.94"
Runoff Area=3.126 ac
Runoff Volume=12,890 cf
2_/ Runoff Depth=1.14"
Tc=20.0 min
LL
CN=58
1-/
1
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)

3 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 36: 3 Postdeveloped
Runoff = 17.97 cfs @ 11.96 hrs, Volume= 36,535 cf, Depth= 3.22"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 10-yr Rainfall=4.94"
Area (ac) CN Description
* 1.920 98 Impervious
* 1.210 61 Grass
3.130 84 Weighted Average
1.210 38.66% Pervious Area
1.920 61.34% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 3B: 3 Postdeveloped
Hydrograph
20--/ ■Runoff
19= r 1 ns7dB
18=j Type II 24-hr
17= P
16✓ 10-yr Rainfall=4.94"
15
1 Runoff Area=3.130 ac
4'
13 Runoff Volume=36,535 cf
12-
u 11=/ Runoff Depth=3.22"
3 19 Tc=5.8 min
LT_
a_j CN=84
7
6-
5'
4=
3-
2=
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)

3 Type !I 24-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 3D: 3 Sand Filter
Inflow Area = 136,343 sf, 61.34% Impervious, Inflow Depth = 3.22" for 10-yr event
Inflow = 17.97 cfs @ 11.96 hrs, Volume= 36,535 cf
Outflow = 2.43 cfs @ 12.19 hrs, Volume= 35,614 cf, Atten= 86%, Lag= 13.7 min
Primary = 2.43 cfs @ 12.19 hrs, Volume= 35,614 cf
Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=749.08' @ 12.19 hrs Surf.Area= 8,252 sf Storage= 18,787 cf
Flood Elev= 750.00' Surf.Area= 9,555 sf Storage=26,965 cf
Plug-Flow detention time= 1,101.0 min calculated for 35,614 cf(97% of inflow)
Center-of-Mass det. time= 1,085.7 min ( 1,892.7 - 807.0 )
Volume Invert Avail.Storage Storage Description
#1 745.50' 26,965 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
745.50 525 0 0
746.00 3,288 953 953
747.00 4,883 4,086 5,039
748.00 6,571 5,727 10,766
749.00 8,136 7,354 18,119
750.00 9,555 8,846 26,965
Device Routing Invert Outlet Devices
#1 Primary 743.00' 24.0" Round Culvert L=49.8' Ke= 0.500
Inlet/Outlet Invert= 743.00'!742.50' S= 0.0100 '!' Cc= 0.900
n= 0.013, Flow Area= 3.14 sf
#2 Device 1 745.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 4.50
Disch. (cfs) 0.000 0.030 0.038 0.047 0.055 0.060
#3 Device 1 748.20' 15.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 749.10' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
#5 Secondary 749.50' 15.0' long x 6.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.37 2.51 2.70 2.68 2.68 2.67 2.65 2.65 2.65
2.65 2.66 2.66 2.67 2.69 2.72 2.76 2.83

3 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Primary OutFlow Max=2.43 cfs @ 12.19 hrs HW=749.08' (Free Discharge)
t Culvert (Passes 2.43 cfs of 34.10 cfs potential flow)
3=Sand Bed Exfiltration (Custom Controls 0.05 cfs)
—3=Low Flow Orifice (Orifice Controls 2.37 cfs @ 3.80 fps)
—4=Grate Top ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=745.50' (Free Discharge)
L5=Emergency Spillway ( Controls 0.00 cfs)
Pond 3D: 3 Sand Filter
Hydrograph
•Inflow
I 17.97 cFs I •Outflow
20 Inflow Area=136,343 sf •
▪Sew,,,
1 S-
174 Storage=18,787 Cf
16',
15',
14-
13
12-
u 11=
3 10i
0 9;
LL :
a=
7-
6=
5- 2.43 ifs
4=
3-
2E A.• ./
D DO cfs
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)

100-YEAR
ROUTING

3 Type 1124-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 3A: 3 Predeveloped
Runoff = 8.99 cfs @ 12.14 hrs, Volume= 30,388 cf, Depth= 2.68"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 100-yr Rainfall=7.39"
Area (ac) CN Description
* 1.563 55 Wooded
* 1.563 61 Grass
3.126 58 Weighted Average
3.126 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 3A: 3 Predeveloped
Hydrograph
10-0/
•Runoff
/ Ia-99 cfs I
9-" Type II 24-hr
8- / 1 o ll - r Rainfall=7.39"
7_i / Ru o Area=3.126 ac
sir / Runoff V• Iu me=38,388 cf
N = R n■ff Depth=2.68"
3 5�
Tc=28.8 min
a 4-,/
CN=58
3-
2-
1-
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)

3 Type 1124-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 36: 3 Postdeveloped
Runoff = 29.83 cfs @ 11.96 hrs, Volume= 62,619 cf, Depth= 5.51"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 100-yr Rainfall=7.39"
Area (ac) CN Description
* 1.920 98 Impervious
* 1.210 61 Grass
3.130 84 Weighted Average
1.210 38.66% Pervious Area
1.920 61.34% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 3B: 3 Postdeveloped
Hydrograph
32 % ■Runoff
30
/ Type II 24-hr
2a=
26✓ 1 100-yr Rainfal1=7.39"
24i Runoff Area=3.130 ac
22-r Runoff Volume=62,619 cf
20i
1SV Runoff Depth=5.51"
0 16=� Tc=5.0 min
LL 14III CN=84
12=
1D=�
/
"r� ...., �r ����rl ��(f��(f���(r
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 9D 95 100 105 110 115 120
Time (hours)

3 Type I!24-hr 100-yr Rainfal1=7.39"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 3D: 3 Sand Filter
Inflow Area = 136,343 sf, 61.34% Impervious, Inflow Depth = 5.51" for 100-yr event
Inflow = 29.83 cfs @ 11.96 hrs, Volume= 62,619 cf
Outflow = 25.73 cfs @ 12.00 hrs, Volume= 61,675 cf, Atten= 14%, Lag= 2.5 min
Primary = 23.92 cfs @ 12.00 hrs, Volume= 61,201 cf
Secondary= 1.81 cfs @ 12.00 hrs, Volume= 474 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=749.64' @ 12.00 hrs Surf.Area= 9,040 sf Storage= 23,589 cf
Flood Elev= 750.00' Surf.Area= 9,555 sf Storage=26,965 cf
Plug-Flow detention time= 656.5 min calculated for 61,660 cf(98% of inflow)
Center-of-Mass det. time= 648.3 min ( 1,440.0 - 791.8 )
Volume Invert Avail.Storage Storage Description
#1 745.50' 26,965 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
745.50 525 0 0
746.00 3,288 953 953
747.00 4,883 4,086 5,039
748.00 6,571 5,727 10,766
749.00 8,136 7,354 18,119
750.00 9,555 8,846 26,965
Device Routing Invert Outlet Devices
#1 Primary 743.00' 24.0" Round Culvert L=49.8' Ke= 0.500
Inlet/Outlet Invert= 743.00'!742.50' S= 0.0100 '!' Cc= 0.900
n= 0.013, Flow Area= 3.14 sf
#2 Device 1 745.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 4.50
Disch. (cfs) 0.000 0.030 0.038 0.047 0.055 0.060
#3 Device 1 748.20' 15.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 749.10' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
#5 Secondary 749.50' 15.0' long x 6.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.37 2.51 2.70 2.68 2.68 2.67 2.65 2.65 2.65
2.65 2.66 2.66 2.67 2.69 2.72 2.76 2.83

3 Type I!24-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Primary OutFlow Max=23.90 cfs @ 12.00 hrs HW=749.64' (Free Discharge)
t=Culvert (Passes 23.90 cfs of 35.91 cfs potential flow)
—2=Sand Bed Exfiltration (Custom Controls 0.06 cfs)
—3=Low Flow Orifice (Orifice Controls 3.27 cfs 5.24 fps)
—4=Grate Top (Weir Controls 20.57 cfs @ 2.40 fps)
Secondary OutFlow Max=1.80 cfs @ 12.00 hrs HW=749.64' (Free Discharge)
L5=Emergency Spillway (Weir Controls 1.80 cfs @ 0.88 fps)
Pond 3D: 3 Sand Filter
Hydrograph
•Inflow
—I zs.s; •Outflow
Inflow Area=135,343 sf gym,,,
32-
25.73 cfs J Peak EI 49._64T
�
2Et I i Storage 23,589 Cf
26
24- I/ /
m 20 '
u 18- I.
a 16;
LI 14
12. /
107 f
a-
/67
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)

DRAINAGE
BASIN #4

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #4
INTRODUCTION:
SUMMARY
Drainage basin#4 includes townhome lots 13-34 in Phase 1, lots 57-75 in Phase 1 B, a portion of Ashton Park
Drive and Hazel Way, and a portion of the Duke Power ROW.A pipe network system routes runoff to sand filter
dry pond#4 which treats the water quality volume.
SUMMARY
DRAINAGE AREAS: (see drainage area map SW-3.0)
Predeveloped Drainage Area 7.88 acres
Postdeveloped Drainage Area 7.88 acres
SOIL TYPES: (see soils map)
Area(ac) Area(%) Soil Type Hydrologic Soil Group
7.88 100% B
Total 7.88 100%
CURVE NUMBER:
Predeveloped CN
Cover Type Area(ac) CN Wtd. CN
Wooded 3.94 50% 55 27.50
Grass 3.94 50% 61 30.50
Total 7.88 58.00
Composite CN Use CN = 58
Postdeveloped CN
Cover Type _ Area(ac) °/n CN Wtd. CN
Impervious 3.93 50% 98 48.94
Grass 3.94 50% 61 30.54
Total 7.88 79.48
'Composite CN Use CN = 79

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #4
HYDROLOGIC CALCULATIONS
Pre-developed Post-developed
Drainage area(DA) 7.88 ac. 7.88 ac
Cuve Number(CN) 58 79
Modified Curve Number(CN) n/a 91
Time of Concentration 0.50 hr. 0.08 hr.
Impervious Percentage 0% 50%
WATER QUALITY VOLUME (1°)
Volume must be released over a period of 2-5 days
Using the runoff volume calculations in the "Simple Method" :
Rv= 0.05+ .009(I)
Rv= 0.50 in/in
WQv=(Design rainfall)(Rv)(Drainage Area)
WQv= 1" rainfall x Rv in/in x 1/12 in/ft x Da=
WQv= 0.328 ac-ft 75% WQv= 0.246 ac-ft
14,278 ft3 10,709 ft3
0.50 in 0.37 in
MODIFIED CURVE NUMBER
CNm= 1000/0 0+5P+10W Qv-10(WQv^2+1.25WQvP)^0.5}
P= rainfall, in inches(use1.0 inches)= 1.00
WQv= water quality volume, in inches= 0.37
CNm 91.4
CHANNEL PROTECTION VOLUME
Q= (P-0.2S)^21(P+0.8S)
Q= accumulated runoff volume, inches
P= accumulated rainfall(potential maximum runoff), inches 2.58 in
S= potential maximum soil retention, inches= 1000/CN-10 = 2.66 in
CN= SCS curve number
Q= 0.89 cfs
Compute Watershed Runoff
CPv= 0.59 ac-ft 50% CPv= 0.293 ac-ft
25,487 cu. Ft 12,744 cu. Ft
Channel Protection Volume Release Rate(1yr, 24 hr storm)
1.5 day
36 hour
Release= 0.197 cfs

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Hot Charlotte, NC 28205
REVISED: 08.03.20 Impervious Calculations - Basin #4
Existing Impervious
Asphalt: 0 sf
Buildings: 0 sf
Concrete: 0 sf
Total Impervious Area: 0 sf
0.00 ac.
Drainage Area: 7.88
Impervious Percentage: 0%
Proposed Impervious
Asphalt: 38,355 sf
Buildings: 99,280 sf
Concrete: 33,680 sf
Total Impervious Area: 171,315 sf
3.93 ac.
Drainage Area: 7.88
Impervious Percentage: 50%

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Sand Filter Design - Basin #4
Sand Filter Design Requirements
Design Method
Design Method TSS
Detention Time 2.0 days
Filter Bed Depth 2.5 ft
Underdrain System Thickness 1.0 ft
SUMMARY
Hydrologic Calculations
Pre-developed Post-developed
Drainage area to pond (Da)= 7.88 ac. 7.88 ac
Cuve Number(CN) 58 79
Adjusted Curve Number(CN) n/a 91
Time of Concentration 0.50 hr. 0.08 hr.
Impervious Percentage 0% 50%
Determine Suface Area to Treat WQv
Surface Area based on Darcy's Equation
Af= (WQv)(df)/((k)(h+d)(t)}
Af= surface area of ponding area(sq ft)
WQv= water quality control volume 10,709 cf
d= filter bed depth 2.5 ft
k= coefficient of permeability of filter media 3.5 ftlday
h= average height of water above filter bed (ft) 1 ft 24" max for WQ storm event
t= design filter bed drain time(days) 2.00 day
Af= 1,093 sf
Determine Dimensions
Length= 50 ft
Width= 22 ft
Area= 1,105 sf

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Sand Filter Design - Basin #4
Stage/Storage Table
Elevation Area Volume
Forebay Main Pond Total Total Forebay Main Pond Total Total
(msl) (sf (sf) (sf) (ac) (cu-ft) (cu-ft) (cu-ft) (ac-ft)
747.5 0 1,105 1,105 0.025 0 0 0 0.000
748 3,024 2,432 5,456 0.125 0 862 862 0.020
749 3,725 3,158 6.883 0.158 3,365 3,646 7,011 0.161
750 4,482 3,941 8,423 0.193 7,459 7,185 14,644 0.336
751 5,296 4,781 10,077 0.231 12,337 11,535 23,872 0.548
752 11,758 0.270 - - 34,768 0.798 _
753 13,213 0.303 - - 47,234 1.084
Stage/Discharge Table
Q. Af(k)(h+d)1(d)
Af= surface area of bonding area(so ft) 1,105 sf
d= filter bed depth 2.5 ft
k= coefficient of permeability of filter media 3.5 ft/day
h= average height of water above filter bed (ft)
Elevation Height Fow Flow Forebay Weir
(msi) (ft) (cf/day) (cfs) Elevation= 750.0
747.5 0 0 0.000 Q. 3.33LhA312
748.5 1 5,415 0.063 Q= 2 yr.storm runoff 34.65 cfs
749.5 2 6,962 0.081 L= weir length L ft
750.5 3 8,509 0.098 h= elevation over weir 1.00 ft
751.5 4 10,056 0.116 L. O/(3.33 x IA3/2)
752.5 5 11,603 0.134 Weir Length I 10 ft(10' min)
753 5.5 12,376 0.143
Peak Attenuation WQv Release Rate(1-inch storm)
Design Peak Flow(cfs) Peak Flow WQv(required) = 10,709 cf
milimmmlw t , + Routed Controlled? WSE WQv(actual) = 10,277 cf
1-year 0.67 15.20 0.60 yes 750.22 2.875 days
10-year 8.58 39.54 6.50 yes 752.09 69 hour
100-year 22.67 69.19 60.65 no 752.90 Release Rate= 0.041 cfs
Top of Dam Elevation: 753.00 (Refer to HydroCAD 1-inch routing table)
Emergency Spillway Elevation: 752.50
Top of outlet structure elevation: 752.00
WQv Water Surface Elevation: 749.24
Sand Bed Elevation: 747.50

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Anti-Flotation Device Calculations
Calculations Given Data Standard Footing Assumptions
Buoyant Weight of Concrete 87.6 Ibslft^3 1. Footing base to be 1 ft. wider than structure
Weight of Water 62.4 Ibslft^3 on all sides.
Safety Factor(S.F.) 1.25 2. Footing depth to be a minimum of 8 inches in depth.
Equations used:
Outlet Structure Weight,W(s)= 4(w+t)x t x h x W(bc)
SUMMARY where, w= outlet box inside dimension,ft.
Displaced Water Weight,W(w)= 4 x(w+2t)x W(w)x h t= structure wall thickness,ft.
h= height of structure,ft.
Required Base Weight,W(b)= (W(w)x S.F.)-W(s) W(bc)= buoyant weight of concrete, Ibslft^3
W(w)= weight of water,Ibs/ft^3
•
Required Footing Volume,V(f)= W(b)/W(bc) S.F.= safety factor
•u e ru ure
Structure Dimensions Object Weights
Height of structure, h = 7 ft. Outlet Structure Weight, W(s) = 5519 lbs
Structure wall thickness,t = 6 in. Displaced Water Weie,W(w)= 8736 lbs
Outlet box inside dimension, w= 4 ft. R�•'d Base Weight,W • = 5401 lbs
Footin• Size
Required Footing Volume,V(t)= 62 cf Standard Footing Length, L= 7.00 ft.
Provided Footing Volume,V(f)= 74 cf - Standard Footing Width,W= 7.00 ft.
Footing Check okay Minimum Footing Depth, D= 1.50 ft.
Footing Size to be used: M Length= 7.00 ft. •
Width = 7.00 ft. Outlet Structure #4
Depth = 1.50 ft.

HYDROCAD
ROUTINGS

1 - INCH
ROUTING

< 4C >
4 P st CNm
ZIA
4 Sand Filter
Subcat Reach 'on. Routing Diagram for 4
Prepared by{enter your company name here), Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

4 Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 4C: 4 Post CNm
Runoff = 7.64 cfs @ 2.97 hrs, Volume= 10,277 cf, Depth= 0.36"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 6-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 7.880 91 Modified CN
7.880 100.00°/% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 4C: 4 Post CNm
Hydrograph
■Runoff
81 7-64 cis
V Type II
' / 6-hr
6 1-inch Rainfall=1.00"
Runoff Area=7.880 ac
5 ' Runoff Volume=10,277 cf
4- Runoff Depth=0.36"
LL
/' Tc=5.0 min
1 CN=91
2: ,
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)

4 Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 4D: 4 Sand Filter
Inflow Area = 343,253 sf, 0.00% Impervious, Inflow Depth = 0.36" for 1-inch event
Inflow = 7.64 cfs @ 2.97 hrs, Volume= 10,277 cf
Outflow = 0.08 cfs @ 6.09 hrs, Volume= 10,277 cf, Atten= 99%, Lag= 187.3 min
Primary = 0.08 cfs @ 6.09 hrs, Volume= 10,277 cf
Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=749.24' @ 6.09 hrs Surf.Area= 7,207 sf Storage= 9,436 cf
Flood Elev= 753.00' Surf.Area= 13,213 sf Storage=48,066 cf
Plug-Flow detention time= 1,340.8 min calculated for 10,277 cf(1000/0 of inflow)
Center-of-Mass det. time= 1,340.6 min ( 1,552.0 -211.4 )
Volume Invert Avail.Storage Storage Description
#1 747.50' 48,066 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
747.50 1,105 0 0
748.00 5,456 1,640 1,640
749.00 6,833 6,145 7,785
750.00 8,423 7,628 15,413
751.00 10,077 9,250 24,663
752.00 11,758 10,918 35,580
753.00 13,213 12,486 48,066
Device Routing Invert Outlet Devices
#1 Primary 745.00' 30.0" Round Culvert L= 38.9' Ke= 0.500
Inlet/Outlet Invert= 745.00'1744.75' S= 0.0064 '1' Cc= 0.900
n= 0.013, Flow Area= 4.91 sf
#2 Device 1 747.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50
Disch. (cfs) 0.000 0.063 0.081 0.098 0.116 0.134 0.143
#3 Device 1 750.00' 18.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 752.00' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100V0 open area)
Limited to weir flow at low heads
#5 Secondary 752.50' 15.0' long x 8.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.43 2.54 2.70 2.69 2.68 2.68 2.66 2.64 2.64
2.64 2.65 2.65 2.66 2.66 2.68 2.70 2.74

4 Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Primary OutFlow Max=0.08 cfs @ 6.09 hrs HW=749.24' (Free Discharge)
L Culvert (Passes 0.08 cfs of 40.70 cfs potential flow)
—2=Sand Bed Exfiltration (Custom Controls 0.08 cfs)
—3=Low Flow Orifice ( Controls 0.00 cfs)
—4=Grate Top ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=747.50' (Free Discharge)
L5=Emergency Spillway ( Controls 0.00 cfs)
Pond 4D: 4 Sand Filter
Hydrograph
•Inflow
z://1)zsa ■Outflow
Inflow Area=343,253 sf :Z1 ,,,
crth
8: Peak Elev=749.24T
7: Storage=9,436 cf
6i
m 5
u -
c 4_
IL -
3� /
2 /
0.08 cfs
1— ;Da.c.fts 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)

4 Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Hydrograph for Pond 4D: 4 Sand Filter
Time Inflow Storage Elevation Outflow Primary Secondary
(hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs)
0.00 0.00 0 747.50 0.00 0.00 0.00
3.00 6.88 3,873 748.39 0.06 0.06 0.00
6.00 0.24 9,404 749.23 0.08 0.08 0.00
9.00 0.00 8,657 749.13 0.07 0.07 0.00
12.00 0.00 7,866 749.01 0.07 0.07 0.00
15.00 0.00 7,097 748.90 0.07 0.07 0.00
18.00 0.00 6,350 748.79 0.07 0.07 0.00
21.00 0.00 5,625 748.67 0.07 0.07 0.00
24.00 0.00 4,922 748.56 0.06 0.06 0.00
27.00 0.00 4,245 748.45 0.06 0.06 0.00
30.00 0.00 3,633 748.35 0.05 0.05 0.00
33.00 0.00 3,087 748.26 0.05 0.05 0.00
36.00 0.00 2,601 748.17 0.04 0.04 0.00
39.00 0.00 2,170 748.10 0.04 0.04 0.00
42.00 0.00 1,789 748.03 0.03 0.03 0.00
45.00 0.00 1,452 747.96 0.03 0.03 0.00
48.00 0.00 1,157 747.90 0.03 0.03 0.00
51.00 0.00 902 747.85 0.02 0.02 0.00
54.00 0.00 686 747.79 0.02 0.02 0.00
57.00 0.00 508 747.74 0.01 0.01 0.00
60.00 0.00 363 747.69 0.01 0.01 0.00
63.00 0.00 251 747.64 0.01 0.01 0.00
66.00 0.00 166 747.61 0.01 0.01 0.00
69.00 0.00 106 747.57 0.00 0.00 0.00
72.00 0.00 65 747.55 0.00 0.00 0.00
75.00 0.00 39 747.53 0.00 0.00 0.00
78.00 0.00 24 747.52 0.00 0.00 0.00
81.00 0.00 14 747.51 0.00 0.00 0.00
84.00 0.00 9 747.51 0.00 0.00 0.00
87.00 0.00 5 747.50 0.00 0.00 0.00
90.00 0.00 3 747.50 0.00 0.00 0.00
93.00 0.00 2 747.50 0.00 0.00 0.00
96.00 0.00 1 747.50 0.00 0.00 0.00
99.00 0.00 1 747.50 0.00 0.00 0.00
102.00 0.00 0 747.50 0.00 0.00 0.00
105.00 0.00 0 747.50 0.00 0.00 0.00
108.00 0.00 0 747.50 0.00 0.00 0.00
111.00 0.00 0 747.50 0.00 0.00 0.00
114.00 0.00 0 747.50 0.00 0.00 0.00
117.00 0.00 0 747.50 0.00 0.00 0.00
120.00 0.00 0 747.50 0.00 0.00 0.00

1 -YEAR
ROUTING

< 4A>
< 4B >
4 Predeveloped 4 Postdevelo ed
AND
4 Sand Filter
Subcat Reach 'on. Routing Diagram for 4
Prepared by{enter your company name here), Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

4 Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 4A: 4 Predeveloped
Runoff = 0.67 cfs @a 12.23 hrs, Volume= 6,082 cf, Depth= 0.21"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 3.940 55 Wooded
* 3.940 61 Grass
7.880 58 Weighted Average
7.880 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 4A: 4 Predeveloped
Hydrograph
0.75--1" ■Runoff
0.7" Iasr I
0.65- Type II 24-h r
061/ 1-yr Rainfall=2.80"
01/ Runoff Area=7.880 ac
0.5i/
0.451/ Runoff Volume=6,082 cf
0.41 % Runoff Depth=0.21"
II 031 % Tc-20.0 min
0.25J CN=58
0 21
0.15
0 1_�
0 D5.v
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)

4 Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 46: 4 Postdeveloped
Runoff = 15.20 cfs @ 11.97 hrs, Volume= 29,875 cf, Depth= 1.04"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 3.933 98 Impervious
* 3.947 61 Grass
7.880 79 Weighted Average
3.947 50.09% Pervious Area
3.933 49.91% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 4B: 4 Postdeveloped
/ Hydrograph
17J ■Runoff
16= 15sa crs
15= Type II 24p-hr
14 / 1=yr Rainfall-2.80"
13:
12 yr Runoff Area=7.880 ac
11= Runoff Volume=29,875 cf
1D=/ 111
9i" Runoff Depth=1.04"
r Tc=5.0 min
LL -i CN=79
6=
5J
4=
3= '
2V - -
0 5 10 15 20 25 30 35 40 45 50 55 66 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

4 Type II 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 4D: 4 Sand Filter
Inflow Area = 343,253 sf, 49.91% Impervious, Inflow Depth = 1.04" for 1-yr event
Inflow = 15.20 cfs @ 11.97 hrs, Volume= 29,875 cf
Outflow = 0.60 cfs @ 13.79 hrs, Volume= 29,860 cf, Atten= 96%, Lag= 109.7 min
Primary = 0.60 cfs @ 13.79 hrs, Volume= 29,860 cf
Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=750.22' @ 13.79 hrs Surf.Area= 8,791 sf Storage= 17,327 cf
Flood Elev= 753.00' Surf.Area= 13,213 sf Storage=48,066 cf
Plug-Flow detention time= 1,345.4 min calculated for 29,853 cf(100% of inflow)
Center-of-Mass det. time= 1,346.2 min ( 2,195.2 - 849.0 )
Volume Invert Avail.Storage Storage Description
#1 747.50' 48,066 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
747.50 1,105 0 0
748.00 5,456 1,640 1,640
749.00 6,833 6,145 7,785
750.00 8,423 7,628 15,413
751.00 10,077 9,250 24,663
752.00 11,758 10,918 35,580
753.00 13,213 12,486 48,066
Device Routing Invert Outlet Devices
#1 Primary 745.00' 30.0" Round Culvert L= 38.9' Ke= 0.500
Inlet/Outlet Invert= 745.00'1744.75' S= 0.0064 '1' Cc= 0.900
n= 0.013, Flow Area= 4.91 sf
#2 Device 1 747.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50
Disch. (cfs) 0.000 0.063 0.081 0.098 0.116 0.134 0.143
#3 Device 1 750.00' 18.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 752.00' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
#5 Secondary 752.50' 15.0' long x 8.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.43 2.54 2.70 2.69 2.68 2.68 2.66 2.64 2.64
2.64 2.65 2.65 2.66 2.66 2.68 2.70 2.74

4 Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Primary OutFlow Max=0.60 cfs @ 13.79 hrs HW=750.22' (Free Discharge)
L=Culvert (Passes 0.60 cfs of 47.11 cfs potential flow)
—2=Sand Bed Exfiltration (Custom Controls 0.09 cfs)
3=Low Flow Orifice (Orifice Controls 0.51 cfs @ 1.51 fps)
—4=Grate Top ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=747.50' (Free Discharge)
L5=Emergency Spillway ( Controls 0.00 cfs)
Pond 4D: 4 Sand Filter
Hydrog raph
•Inflow
1520 cfs •Outflow
17 Inflow Area=343,253 sf : y
16 Peak Elev=750.22T
15-
14: Storage=17,327 cf
13-
12=
11-
10=
u 9-
o a'
u_ 7_
6'.
/_ OM
2_ osods
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)

10-YEAR
ROUTING

4 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 4A: 4 Predeveloped
Runoff = 8.58 cfs @ 12.15 hrs, Volume= 32,493 cf, Depth= 1.14"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 10-yr Rainfall=4.94"
Area (ac) CN Description
* 3.940 55 Wooded
* 3.940 61 Grass
7.880 58 Weighted Average
7.880 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 4A: 4 Predeveloped
Hydrograph
/ ■Runoff
Iris cfs I
s1 Type II 24-hr
10-yr Rainfall=4.94"
Runoff Area=7.880 ac
61 ♦ Runoff Volume=32,493 cf
51 / Runoff Depth=1.14"
j Tc 20,0 min
a 4/
CN=S
31-Z
1
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)

4 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 46: 4 Postdeveloped
Runoff = 39.54 cfs @ 11.96 hrs, Volume= 78,664 cf, Depth= 2.75"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type 1124-hr 10-yr Rainfall=4.94"
Area (ac) CN Description
* 3.933 98 Impervious
* 3.947 61 Grass
7.880 79 Weighted Average
3.947 50.09% Pervious Area
3.933 49.91% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 4B: 4 Postdeveloped
Hydrograph
441". ■Runoff
42', / I 39s4ds
43a-
D Type II 24-hr
36', 10-yr Rainfall=4.94"
34
32 r Runoff Area=7.880-ac
3D
2a- Runoff Vo l u nne=78,664 cf
El
Runoff Depth=2.75"
3 2 2D
Tc=5.0 min
19', / CN=79
15✓
14-
12€
D
a-
1
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)

4 Type II 24-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 4D: 4 Sand Filter
Inflow Area = 343,253 sf, 49.91% Impervious, Inflow Depth = 2.75" for 10-yr event
Inflow = 39.54 cfs @ 11.96 hrs, Volume= 78,664 cf
Outflow = 6.50 cfs @ 12.15 hrs, Volume= 78,647 cf, Atten= 84%, Lag= 11.0 min
Primary = 6.50 cfs @ 12.15 hrs, Volume= 78,647 cf
Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=752.09' @ 12.15 hrs Surf.Area= 11,890 sf Storage= 36,652 cf
Flood Elev= 753.00' Surf.Area= 13,213 sf Storage=48,066 cf
Plug-Flow detention time= 560.3 min calculated for 78,647 cf(100% of inflow)
Center-of-Mass det. time= 560.2 min ( 1,381.1 - 821.0 )
Volume Invert Avail.Storage Storage Description
#1 747.50' 48,066 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
747.50 1,105 0 0
748.00 5,456 1,640 1,640
749.00 6,833 6,145 7,785
750.00 8,423 7,628 15,413
751.00 10,077 9,250 24,663
752.00 11,758 10,918 35,580
753.00 13,213 12,486 48,066
Device Routing Invert Outlet Devices
#1 Primary 745.00' 30.0" Round Culvert L= 38.9' Ke= 0.500
Inlet/Outlet Invert= 745.00'1744.75' S= 0.0064 '1' Cc= 0.900
n= 0.013, Flow Area= 4.91 sf
#2 Device 1 747.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50
Disch. (cfs) 0.000 0.063 0.081 0.098 0.116 0.134 0.143
#3 Device 1 750.00' 18.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 752.00' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
#5 Secondary 752.50' 15.0' long x 8.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.43 2.54 2.70 2.69 2.68 2.68 2.66 2.64 2.64
2.64 2.65 2.65 2.66 2.66 2.68 2.70 2.74

4 Type 1124-hr 10-yr Rainfall=4.94"
Prepared by{enter your company name here) Printed 7/30/2020
HydreCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Primary OutFlow Max=6.44 cfs @ 12.15 hrs HW=752.09' (Free Discharge)
L Culvert (Passes 6.44 cfs of 57.12 cfs potential flow)
3=Sand Bed Exfiltration (Custom Controls 0.13 cfs)
—3=Low Flow Orifice (Orifice Controls 4.89 cfs @ 6.53 fps)
—4=Grate Top (Weir Controls 1.42 cfs @ 0.98 fps)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=747.50' (Free Discharge)
L5=Emergency Spillway ( Controls 0.00 cfs)
Pond 4D: 4 Sand Filter
Hydrograph
■Inflow
139.54 cFs I •Outflow
44, Inflow Area=343,253 sf : y
42- ■
401 ' —
36
36-
34=
32- '3D=
26-
N 26-
u 24� I
22;
0 201 •187 ■
16;
141"
12i 'fi-53 ds
1D= '
6; //
D DO cfs
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)

100-YEAR
ROUTING

4 Type 1124-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 4A: 4 Predeveloped
Runoff = 22.67 cfs @ 12.14 hrs, Volume= 76,602 cf, Depth= 2.68"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 100-yr Rainfall=7.39"
Area (ac) CN Description
* 3.940 55 Wooded
* 3.940 61 Grass
7.880 58 Weighted Average
7.880 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 4A: 4 Predeveloped
Hydrograph
25 •Runoff
24; / F r-rm
23_; Type II 24-h r
22.
2201 / 100-yr Rainfall=7.39"
9✓ / Runoff Area=7.880 ac
1 8✓
7
16✓ Runoff Volume=76,602 cf
15 /
14-r Runoff Depth=2.68"
• 13;
0 12 Tc=20.0 min
u f
19 CN=58
98
6 / 1/
5',"
4
2 /r
0 5 10 15 20 25 30 35 40 45 50 55 fi0 45 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

4 Type 1124-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 46: 4 Postdeveloped
Runoff = 69.19 cfs @ 11.96 hrs, Volume= 141,381 cf, Depth= 4.94"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 100-yr Rainfall=7.39"
Area (ac) CN Description
* 3.933 98 Impervious
* 3.947 61 Grass
7.880 79 Weighted Average
3.947 50.09% Pervious Area
3.933 49.91% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 4B: 4 Postdeveloped
Hydrograph
75✓ ■Runoff
/ 69.19 ds
70- , Type II 24-hr
::i
100-yr Rainfall79"
r
55_ Runoff Area=7.880 ac
50/ I Runoff Volume=141,381 cf
451-/ Runoff Depth=4.94"
35� Tc=5.0 min
°
LL 3D✓ CN=79
25
/
20=
15:%
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)

4 Type I!24-hr 100-yr Rainfal1=7.39"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 4D: 4 Sand Filter
Inflow Area = 343,253 sf, 49.91% Impervious, Inflow Depth = 4.94" for 100-yr event
Inflow = 69.19 cfs @ 11.96 hrs, Volume= 141,381 cf
Outflow = 60.65 cfs @ 12.00 hrs, Volume= 141,363 cf, Atten= 12%, Lag= 2.3 min
Primary = 50.89 cfs @ 12.00 hrs, Volume= 137,749 cf
Secondary= 9.76 cfs @ 12.00 hrs, Volume= 3,614 cf
Routing by Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=752.90' @ 12.00 hrs Surf.Area= 13,071 sf Storage=46,784 cf
Flood Elev= 753.00' Surf.Area= 13,213 sf Storage=48,066 cf
Plug-Flow detention time= 330.5 min calculated for 141,328 cf(100% of inflow)
Center-of-Mass det. time= 331.7 min ( 1,136.0 - 804.3 )
Volume Invert Avail.Storage Storage Description
#1 747.50' 48,066 cf Detention (Prismatic) Listed below (Recalc)
Elevation Surf Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
747.50 1,105 0 0
748.00 5,456 1,640 1,640
749.00 6,833 6,145 7,785
750.00 8,423 7,628 15,413
751.00 10,077 9,250 24,663
752.00 11,758 10,918 35,580
753.00 13,213 12,486 48,066
Device Routing Invert Outlet Devices
#1 Primary 745.00' 30.0" Round Culvert L= 38.9' Ke= 0.500
Inlet/Outlet Invert= 745.00'1744.75' S= 0.0064 7' Cc= 0.900
n= 0.013, Flow Area= 4.91 sf
#2 Device 1 747.50' Sand Bed Exfiltration
Head (feet) 0.00 1.00 2.00 3.00 4.00 5.00 5.50
Disch. (cfs) 0.000 0.063 0.081 0.098 0.116 0.134 0.143
#3 Device 1 750.00' 18.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 752.00' 3.0"x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
#5 Secondary 752.50' 15.0' long x 8.0' breadth Emergency Spillway
Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00
2.50 3.00 3.50 4.00 4.50 5.00 5.50
Coef. (English) 2.43 2.54 2.70 2.69 2.68 2.68 2.66 2.64 2.64
2.64 2.65 2.65 2.66 2.66 2.68 2.70 2.74

4 Type II 24-hr 100-yr Rainfall=7.39"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Primary OutFlow Max=50.64 cfs @ 12.00 hrs HW=752.90' (Free Discharge)
L=Culvert (Passes 50.64 cfs of 60.95 cfs potential flow)
—2=Sand Bed Exfiltration (Custom Controls 0.14 cfs)
—3=Low Flow Orifice (Orifice Controls 5.88 cfs @ 7.83 fps)
—4=Grate Top (Weir Controls 44.62 cfs @ 3.10 fps)
Secondary OutFlow Max=9.62 cfs @ 12.00 hrs HW=752.90' (Free Discharge)
L5=Emergency Spillway (Weir Controls 9.62 cfs @ 1.61 fps)
Pond 4D: 4 Sand Filter
Hydrograph
•Inflow
/./
69.19 cfs I •Outflow
1 Inflow Area=343,253 sf r ,,,
75: ' 60.fi5 cfs / Peak EIev752.9OT
TO
65! • 4 7
yfi0
50.89 cfs
55
50-
45:/
//: [ Ill
u 40
3
35- /
3,0 I /
E : '__'Li
�'
5= I//I/. ,in.
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)

DRAINAGE
BASIN #5

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #5
INTRODUCTION:
SUMMARY
Drainage basin#5 includes townhome lots 91-105 in Phase 1 B and a portion of Prince Garrett Way.A pipe
network system routes runoff to a StormTech underground detention system and through a BayFilter vault
which treats the water quality volume.A flow splitter upstream of the underground detention allows higher
flows to bypass the system.
DRAINAGE AREAS: (see drainage area map SW-3.0)
Predeveloped Drainage Area 1.93 acres
Postdeveloped Drainage Area 1.93 acres
SOIL TYPES: (see soils map)
Area(ac) Area(%) Soil Type Hydrologic Soil Group
1.93 100% B
Total 1.93 100%
CURVE NUMBER:
Predeveloped CN
Cover Type Area(ac) % CN Wtd. CN
Wooded 0.97 50% 55 27.50
Grass 0.97 50% 61 30.50
Total 1.93 58.00
Composite CN Use CN = 58
Postdeveloped CN
Cover Type Area(ac) % CN Wtd. CN
Impervious 1.08 56% 98 54.61
Grass 0.85 44% 61 27.01
Total 1.93 81.62
'Composite CN Use CN = 82

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #5
HYDROLOGIC CALCULATIONS
Pre-developed Post-developed
Drainage area(DA) 1.93 ac. 1.93 ac
Cuve Number(CN) 58 82
Modified Curve Number(CN) n/a 92
Time of Concentration 0.33 hr. 0.08 hr.
Impervious Percentage 0% 56%
WATER QUALITY VOLUME (1°)
Volume must be released over a period of 2-5 days
Using the runoff volume calculations in the "Simple Method" :
Rv= 0.05+ .009(I)
Rv= 0.55 in/in
WQv=(Design rainfall)(Rv)(Drainage Area)
WQv= 1" rainfall x Rv in/in x 1/12 in/ft x Da=
WQv= 0.089 ac-ft 75% WQv= 0.067 ac-ft
3,864 ft3 2,898 ft3
0.55 in 0.41 in
MODIFIED CURVE NUMBER
CNm= 1000/0 0+5P+10W Qv-10(WQv^2+1.25WQvP)^0.5}
P= rainfall, in inches(use1.0 inches)= 1.00
WQv= water quality volume, in inches= 0.41
CNm 92.2
CHANNEL PROTECTION VOLUME
Q= (P-0.2S)^21(P+0.8S)
Q= accumulated runoff volume, inches
P= accumulated rainfall(potential maximum runoff), inches 2.58 in
S= potential maximum soil retention, inches= 1000/CN-10 = 2.20 in
CN= SCS curve number
Q= 1.06 cfs
Compute Watershed Runoff
CPv= 0.170 ac-ft 50% CPv= 0.085 ac-ft
7,407 cu. Ft 3,703 cu. Ft
Channel Protection Volume Release Rate(1yr, 24 hr storm)
1.5 day
36 hour
Release= 0.057 cfs

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Hot Charlotte, NC 28205
REVISED: 08.03.20 Impervious Calculations - Basin #5
Existing Impervious
Asphalt: 0 sf
Buildings: 0 sf
Concrete: 0 sf
Total Impervious Area: 0 sf
0.00 ac.
Drainage Area: 1.93
Impervious Percentage: 0%
Proposed Impervious
Asphalt: 5,975 sf
Buildings: 32,530 sf
Concrete: 8,350 sf
Total Impervious Area: 46,855 sf
1.08 ac.
Drainage Area: 1.93
Impervious Percentage: 56%

HYDROCAD
ROUTINGS

1 - INCH
ROUTING

5 Post N m AFS
/wSPlitter N
.Q
5E
AD
Overflow
5 UGD
till
Total Discharge
Subcat Reach 'on. Iti Routing Diagram for 5 ADSPrepared by{enter your company name here), Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

5 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 5C: 5 Post CNm
Runoff = 2.09 cfs @ 2.97 hrs, Volume= 2,820 cf, Depth= 0.40"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 6-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 1.930 92 Modified CN
1.930 100.00°/% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post To
Subcatchment 5C: 5 Post CNm
Hydrograph
■Runoff
I2os�I
2 Type II
6-hr
1-inch Rainfall=1.00"
Runoff Area=1.930 ac
17, Runoff Volume=2,820 cf
LL 1_ Runoff Depth=0.40"
Tc=5.0 min
CN=92
0 45d1%///////////////f//f//f//////////////////////////////////////////////////////f//f//f////////
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)

5 ADS Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond FS: Flow Spliiter
Inflow Area = 84,071 sf, 0.00% Impervious, Inflow Depth = 0.40" for 1-inch event
Inflow = 2.09 cfs @ 2.97 hrs, Volume= 2,820 cf
Outflow = 2.09 cfs @ 2.97 hrs, Volume= 2,820 cf, Atten= 0°/0, Lag= 0.0 min
Primary = 2.09 cfs @ 2.97 hrs, Volume= 2,820 cf
Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=750.04' @ 6.14 hrs
Flood Elev= 755.25'
Device Routing Invert Outlet Devices
#1 Primary 748.60' 12.0" Round Low Flow L= 8.2' Ke= 0.500
Inlet/Outlet Invert= 748.60'!748.54' S= 0.0073 '1' Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf
#2 Secondary 748.00' 18.0" Round High Flow L= 20.0' Ke= 0.500
Inlet/Outlet Invert=748.00'!747.75' S= 0.0125 '1' Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf
#3 Device 2 750.50' Weir Wall, Cv=2.62 (C= 3.28)
Elev. (feet) 750.50 754.75 754.75
Width (feet) 4.00 4.00 0.00
Primary OutFlow Max=2.08 cfs @ 2.97 hrs HW=749.57' TW=748.04' (Dynamic Tailwater)
L1=Low Flow (Barrel Controls 2.08 cfs @ 3.39 fps)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=748.00' TW=0.00' (Dynamic Tailwater)
t-2=High Flow ( Controls 0.00 cfs)
L3=Weir Wall ( Controls 0.00 cfs)

5 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond FS: Flow Splitter
Hydrograph
0 Inflow
zus'I Outflow
209 cis Inflow Area=84,071 sf o Secmandary
l2.09 cfs.r
Peak Elev=750.04'
2-
7/7
u
it 1-
1
/
'�'
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)

5 ADS Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 5D: 5 UGD
Inflow Area = 84,071 sf, 0.00% Impervious, Inflow Depth = 0.40" for 1-inch event
Inflow = 2.09 cfs @ 2.97 hrs, Volume= 2,820 cf
Outflow = 0.01 cfs @ 6.11 hrs, Volume= 758 cf, Atten= 99%, Lag= 188.7 min
Primary = 0.01 cfs @ 6.11 hrs, Volume= 758 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=750.04' @ 6.11 hrs Surf.Area= 1,476 sf Storage= 2,730 cf
Flood Elev= 750.50' Surf.Area= 1,476 sf Storage= 3,004 cf
Plug-Flow detention time= 669.3 min calculated for 758 cf(27% of inflow)
Center-of-Mass det. time= 631.6 min ( 841.0 -209.5 )
Volume Invert Avail.Storage Storage Description
#1A 747.00' 566 cf 11.00'W x 53.46'L x 3.50'H Field A
2,058 cf Overall -643 cf Embedded = 1,415 cf x 40.0%Voids
#2A 747.50' 643 cf ADS_StormTech SC-740 +Cap x 14 Inside#1
Effective Size=44.6"W x 30.0"H => 6.45 sf x 7.12'L =45.9 cf
Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap
14 Chambers in 2 Rows
#36 747.00' 493 cf 11.00'W x 46.34'L x 3.50'H Field B
1,784 cf Overall - 551 cf Embedded = 1,233 cf x 40.0%Voids
#46 747.50' 551 cf ADS_StormTech SC-740 +Cap x 12 Inside#3
Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.12'L =45.9 cf
Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap
12 Chambers in 2 Rows
#5C 747.00' 383 cf 6.25'W x 60.58'L x 3.50'H Field C
1,325 cf Overall - 368 cf Embedded = 958 cf x 40.0% Voids
#6C 747.50' 368 cf ADS_StormTech SC-740 +Cap x 8 Inside#5
Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.12'L =45.9 cf
Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap
3,004 cf Total Available Storage
Storage Group A created with Chamber Wizard
Storage Group B created with Chamber Wizard
Storage Group C created with Chamber Wizard
Device Routing Invert Outlet Devices (Turned on 1 times)
#1 Primary 746.50' 8.0" Round Outlet L= 26.4' Ke= 0.500
Inlet/Outlet Invert= 746.50'!746.35' S= 0.0057 '1' Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.35 sf
#2 Device 1 749.17' BayFilter Cartridges X 2.00 0.330" Diameter, C= 0.600
Inlet/Outlet Elev. = 0.00'1746.50' Starts@749.17' Breaks@747.00'
#3 Device 2 747.60' StormTech to BayFilter 12.000" Diameter, C= 0.600
8.8' Long Tube, Hazen-Williams C= 130
Inlet/Outlet Elev. = 747.60'!747.50'

5 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Primary OutFlow Max=0.01 cfs @ 6.11 hrs HW=750.04' TW=0.00' (Dynamic Tailwater)
L1=Outlet (Passes 0.01 cfs of 2.85 cfs potential flow)
L2=BayFilter Cartridges (Orifice Controls 0.01 cfs @ 9.05 fps)
L3=StormTech to BayFilter (Passes 0.01 cfs of 3.42 cfs potential flow)
Pond 5D: 5 UGD
Hyd rag raph
■Inflow
I 2.09 I 0 Primary 1
Inflow Area=84,071 sf
2-Peak Elegy=750.04'
Storage=2,730 cf
LL 1
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)

5 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 5E: Overflow
Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 0°/0, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 5E: Overflow
Hydrograph
■Inflow
❑Primary I
cfs por
U
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)

5 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 5F: Total Discharge
Inflow Area = 84,071 sf, 0.00% Impervious, Inflow Depth = 0.11" for 1-inch event
Inflow = 0.01 cfs @ 6.11 hrs, Volume= 758 cf
Primary = 0.01 cfs @ 6.11 hrs, Volume= 758 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 5F: Total Discharge
Hydrograph
■Inflow
0-012 1101 cfs ❑Primary
0.011 nmrcr8���,` Inflow Area=84,071 sf
0.01v�:�r'+r��J4
0-009
0.008_
0-008-
0.007_
0 007 -/
•
t 0-006=
3 0-006=
0 0.005
• o-aa5 '
0-004"'
0-004"'
0-003"'
0-003=
0-002=
0-001"'
0.001
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)

1 -YEAR
ROUTING

< 5A>
< 5B)
5 Pre 5 Post
FS
.
Flow Splitter N
.Q
5E
/51:\
Overflow
5 UGD
5F
Total Discharge
Subcat Reach on. Link Routing Diagram for 5ADS
Prepared by{enter your company name here), Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

5 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 5A: 5 Pre
Runoff = 0.16 cfs @ 12.23 hrs, Volume= 1,490 cf, Depth= 0.21"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 0.965 55 Wooded
* 0.965 61 Grass
1.930 58 Weighted Average
1.930 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ftift) (ftlsec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 5A: 5 Pre
// Hydrograph
0.18' •Runoff
0.171 Ia1scI
0.167 Type II 24-hr
0.15K, 1-yr Rainfall=2.80"
0-14= V
0-13 Runoff Area=1.930 ac
0.1✓ Runoff Volume=1,490 cf
0.1.
1 Runoff Depth=0.21"
E 0.08 % Tc=20.0 min
007 CN=58
0-05
0.02V /
0 01 le,{r(, ::.., .. tfr��ff��tf��ff�r��� l��� r rr,�f( ,r{frr�ff�,�frrr�ff�,�fr��ff�
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)

5 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 56: 5 Post
Runoff = 4.37 cfs @ 11.96 hrs, Volume= 8,571 cf, Depth= 1.22"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 1.076 98 Impervious
* 0.854 61 Grass
1.930 82 Weighted Average
0.854 44.25% Pervious Area
1.076 55.75% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 5B: 5 Post
Hydrograph
0 Runoff
Type 1124-h r
41 141-yr Rainfall=2.80"
Runoff Area=1.930 ac
Runoff Volume=8,571 cf
Runoff Depth=1.22"
LL Tc=5.0 min
2/
CN=82
0 5 1❑ 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

5 ADS Type !I 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond FS: Flow Spliiter
Inflow Area = 84,071 sf, 55.75% Impervious, Inflow Depth = 1.22" for 1-yr event
Inflow = 4.37 cfs @ 11.96 hrs, Volume= 8,571 cf
Outflow = 4.37 cfs @ 11.96 hrs, Volume= 8,571 cf, Atten= 0°/0, Lag= 0.0 min
Primary = 4.28 cfs @ 11.96 hrs, Volume= 6,069 cf
Secondary= 2.83 cfs @ 12.04 hrs, Volume= 2,503 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=750.86' @ 12.04 hrs
Flood Elev= 755.25'
Device Routing Invert Outlet Devices
#1 Primary 748.60' 12.0" Round Low Flow L= 8.2' Ke= 0.500
Inlet!Outlet Invert= 748.60'!748.54' S= 0.0073 '!' Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf
#2 Secondary 748.00' 18.0" Round High Flow L= 20.0' Ke= 0.500
Inlet/Outlet Invert=748.00'!747.75' S= 0.0125 '!' Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf
#3 Device 2 750.50' Weir Wall, Cv=2.62 (C= 3.28)
Elev. (feet) 750.50 754.75 754.75
Width (feet) 4.00 4.00 0.00
Primary OutFlow Max=3.34 cfs @ 11.96 hrs HW=750.44' TW=749.66' (Dynamic Tailwater)
L1=Low Flow (Inlet Controls 3.34 cfs @ 4.25 fps)
Secondary OutFlow Max=2.59 cfs @ 12.04 hrs HW=750.84' TW=0.00' (Dynamic Tailwater)
t-2=High Flow (Passes 2.59 cfs of 12.30 cfs potential flow)
L3=Weir Wall (Weir Controls 2.59 cfs @ 1.91 fps)

5 ADS Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond FS: Flow Splitter
Hydrograph
0 Inflow
4.37 cfs 1 Outflow
„,/
43;Lis Inflow Area=84,071 sf o Primary
1 428 cis 1
V Peak Elev=750.86'
4
3 1 2.83 cfs 1
o
— 2-
1
n Zr
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)

5 ADS Type !I 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 5D: 5 UGD
Inflow Area = 84,071 sf, 55.75% Impervious, Inflow Depth = 0.87" for 1-yr event
Inflow = 4.28 cfs @ 11.96 hrs, Volume= 6,069 cf
Outflow = 2.23 cfs @ 12.03 hrs, Volume= 4,007 cf, Atten=48%, Lag=4.1 min
Primary = 2.23 cfs @ 12.03 hrs, Volume= 4,007 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev= 147,874.92' @ 12.03 hrs Surf.Area= 1,476 sf Storage= 3,004 cf
Flood Elev= 750.50' Surf.Area= 1,476 sf Storage= 3,004 cf
Plug-Flow detention time= 520.8 min calculated for 4,007 cf(66%of inflow)
Center-of-Mass det. time=409.4 min ( 1,237.1 - 827.7 )
Volume Invert Avail.Storage Storage Description
#1A 747.00' 566 cf 11.00'W x 53.46'L x 3.50'H Field A
2,058 cf Overall -643 cf Embedded = 1,415 cf x 40.0%Voids
#2A 747.50' 643 cf ADS_StormTech SC-740 +Cap x 14 Inside#1
Effective Size=44.6"W x 30.0"H => 6.45 sf x 7.12'L =45.9 cf
Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap
14 Chambers in 2 Rows
#36 747.00' 493 cf 11.00'W x 46.34'L x 3.50'H Field B
1,784 cf Overall - 551 cf Embedded = 1,233 cf x 40.0%Voids
#46 747.50' 551 cf ADS_StormTech SC-740 +Cap x 12 Inside#3
Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.12'L =45.9 cf
Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap
12 Chambers in 2 Rows
#5C 747.00' 383 cf 6.25'W x 60.58'L x 3.50'H Field C
1,325 cf Overall - 368 cf Embedded = 958 cf x 40.0% Voids
#6C 747.50' 368 cf ADS_StormTech SC-740 +Cap x 8 Inside#5
Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.12'L =45.9 cf
Overall Size= 51.0"W x 30.0"H x 7.56'L with 0.44' Overlap
3,004 cf Total Available Storage
Storage Group A created with Chamber Wizard
Storage Group B created with Chamber Wizard
Storage Group C created with Chamber Wizard
Device Routing Invert Outlet Devices
#1 Primary 746.50' 8.0" Round Outlet L= 26.4' Ke= 0.500
Inlet/Outlet Invert= 746.50'!746.35' S= 0.0057 '!' Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.35 sf
#2 Device 1 749.17' BayFilter Cartridges X 2.00 0.330" Diameter, C= 0.600
Inlet/Outlet Elev. = 0.00'1746.50' Starts@749.17' Breaks@747.00'
#3 Device 2 747.60' StormTech to BayFilter 12.000" Diameter, C= 0.600
8.8' Long Tube, Hazen-Williams C= 130
Inlet/Outlet Elev. = 747.60'!747.50'

5 ADS Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Primary OutFlow Max=2.06 cfs @ 12.03 hrs HW=130,419.57' TW=0.00' (Dynamic Tailwater)
L1=Outlet (Passes 2.06 cfs of 590.00 cfs potential flow)
L2=BayFilter Cartridges (Orifice Controls 2.06 cfs © 1,733.88 fps)
L3=StormTech to BayFilter (Passes 2.06 cfs of 1,345.13 cfs potential flow)
Pond 5D: 5 UGD
Hydrog raph
■Inflow
4.28 cfs I 0 Primary
� Inflow Area=B ,071 sf
4= Peak Elev=147,874.92'
Storage=3,004 cf
3—'
3 ��cfs 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)

5 ADS Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 5E: Overflow
Inflow = 2.83 cfs @ 12.04 hrs, Volume= 2,503 cf
Primary = 2.83 cfs @ 12.04 hrs, Volume= 2,503 cf, Atten= 0%, Lag= O.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 5E: Overflow
Hyd rag raph
■Inflow
z.ss ds ❑Primary
I
3 z83
r
2_ '
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)

5 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 5F: Total Discharge
Inflow Area = 84,071 sf, 55.75% Impervious, Inflow Depth = 0.93" for 1-yr event
Inflow = 4.98 cfs @ 12.03 hrs, Volume= 6,510 cf
Primary = 4.98 cfs @ 12.03 hrs, Volume= 6,510 cf, Atten= 0'M . Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 5F: Total Discharge
Hydrograph
❑Inflow
49ec I 0 Primary
5- 4�; InfIo A = 4,0 1 s
4-'
-
u 3
LL
2 /
1-'
0"%////// //////////////////////////////J//J/////////////////////////////////J//J//J//%
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)

DRAINAGE
BASIN #6

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #6
INTRODUCTION:
SUMMARY
Drainage basin#6 includes townhome lots 86-90&106-133 in Phase 1 B and a portion of Waterway Drive,
Garrison Grove Lane and Prince Garrett Way.A pipe network system routes runoff to a StormTech
underground detention system and through a BayFilter vault which treats the water quality volume.A flow
splitter upstream of the underground detention allows higher flows to bypass the system.
DRAINAGE AREAS: (see drainage area map SW-3.0)
Predeveloped Drainage Area 5.72 acres
Postdeveloped Drainage Area 5.72 acres
SOIL TYPES: (see soils map)
Area(ac) Area(%) Soil Type Hydrologic Soil Group
5.72 100% B
Total 5.72 100%
CURVE NUMBER:
Predeveloped CN
Cover Type Area(ac) % CN Wtd. CN
Wooded 2.86 50% 55 27.50
Grass 2.86 50% 61 30.50
Total 5.72 58.00
Composite CN Use CN = 58
Postdeveloped CN
Cover Type _ Area(ac) % CN Wtd. CN
Impervious 3.90 68% 98 66.78
Grass 1.82 32% 61 19.43
Total 5.72 86.21
'Composite CN Use CN = 86

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #6
HYDROLOGIC CALCULATIONS
Pre-developed Post-developed
Drainage area(DA) 5.72 ac. 5.72 ac
Cuve Number(CN) 58 86
Modified Curve Number(CN) n/a 94
Time of Concentration 0.33 hr. 0.08 hr.
Impervious Percentage 0% 68%
WATER QUALITY VOLUME (1°)
Volume must be released over a period of 2-5 days
Using the runoff volume calculations in the "Simple Method" :
Rv= 0.05+ .009(I)
Rv= 0.66 Win
WQv=(Design rainfall)(Rv)(Drainage Area)
WQv= 1" rainfall x Rv in/in x 1/12 in/ft x Da=
WQv= 0.316 ac-ft 75% WQv= 0.237 ac-ft
13,776 ft3 10,332 ft3
0.66 in 0.50 in
MODIFIED CURVE NUMBER
CNm= 1000/0 0+5P+10W Qv-10(WQv^2+1.25WQvP)^0.5}
P= rainfall, in inches(use1.0 inches)= 1.00
WQv= water quality volume, in inches= 0.50
CNm 93.9
CHANNEL PROTECTION VOLUME
Q= (P-0.2S)^21(P+0.8S)
Q= accumulated runoff volume, inches
P= accumulated rainfall(potential maximum runoff), inches 2.58 in
S= potential maximum soil retention, inches= 1000/CN-10 = 1.63 in
CN= SCS curve number
Q= 1.31 cfs
Compute Watershed Runoff
CPv= 0.624 ac-ft 50% CPv= 0.312 ac-ft
27,189 cu. Ft 13,595 cu. Ft
Channel Protection Volume Release Rate(1yr, 24 hr storm)
1.5 day
36 hour
Release= 0.210 cfs

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Impervious Calculations - Basin #6
Existing Impervious
Asphalt: 0 sf
Buildings: 0 sf
Concrete: 0 sf
Total Impervious Area: 0 sf
0.00 ac.
Drainage Area: 5.72
Impervious Percentage: 0%
Proposed Impervious
Asphalt: 54,795 sf
Buildings: 72,650 sf
Concrete: 42,390 sf
Total Impervious Area: 169,835 sf
3.90 ac.
Drainage Area: 5.72
Impervious Percentage: 68%

HYDROCAD
ROUTINGS

1 - INCH
ROUTING

<6C>
6 Post Nm AFS
.
Splitter
Ns
A/ow
6E�___
Overflow
6 LJ G D \it
6F
Total Discharge
Subcat Reach 'on. Iti Routing Diagram for 6 ADSPrepared by{enter your company name here), Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

6 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 6C: 6 Post CNm
Runoff = 7.64 cfs @ 2.96 hrs, Volume= 10,460 cf, Depth= 0.50"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 6-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 5.720 94 Modified CN
5.720 100.00°/% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post To
Subcatchment 6C: 6 Post CNm
Hydrograph
■Runoff
817.84 Ifs
1 Type II
' 6-hr
6 1-inch Rainfall=1.00"
Runoff Area=5.720 ac
Runoff Volume=10,460 cf
4- Runoff Depth=0.50"
LL
3. / Tc=5.0 min
CN=94
2-
1-- p
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)

6 ADS Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond FS: Flow Spliiter
Inflow Area = 249,163 sf, 0.00% Impervious, Inflow Depth = 0.50" for 1-inch event
Inflow = 7.64 cfs @ 2.96 hrs, Volume= 10,460 cf
Outflow = 7.64 cfs @ 2.96 hrs, Volume= 10,460 cf, Atten= 0°/0, Lag= 0.0 min
Primary = 7.64 cfs @ 2.96 hrs, Volume= 10,460 cf
Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=738.05' @ 6.08 hrs
Flood Elev= 743.25'
Device Routing Invert Outlet Devices
#1 Primary 734.00' 18.0" Round Low Flow L= 12.3' Ke= 0.500
Inlet/Outlet Invert= 734.00'1733.92' S= 0.0065 '1' Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Secondary 733.50' 30.0" Round High Flow L= 71.5' Ke= 0.500
Inlet 1 Outlet Invert= 733.50'1731.20' S= 0.0322 '1' Cc= 0.900
n= 0.012, Flow Area= 4.91 sf
#3 Device 2 738.25' Weir Wall, Cv=2.62 (C= 3.28)
Elev. (feet) 738.25 742.75 742.75
Width (feet) 4.00 4.00 0.00
Primary OutFlow Max=7.54 cfs @ 2.96 hrs HW=735.80' TW=734.83' (Dynamic Tailwater)
L1=Low Flow (Barrel Controls 7.54 cfs @ 4.51 fps)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=733.50' TW=0.00' (Dynamic Tailwater)
t-2=High Flow ( Controls 0.00 cfs)
L3=Weir Wall ( Controls 0.00 cfs)

6 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond FS: Flow Splitter
Hydrograph
0 Inflow
rs!cts I Outflow
6+c Inflow Area=249 '163 cf ❑Primaryr ■Secondary
81 " Peak Elegy=738.05T
7-
6-
a 5
g 4-
IL -
3-
2- ' •-
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)

6 ADS Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 6D: 6 UGD
Inflow Area = 249,163 sf, 0.00% Impervious, Inflow Depth = 0.50" for 1-inch event
Inflow = 7.64 cfs @ 2.96 hrs, Volume= 10,460 cf
Outflow = 0.03 cfs @ 6.11 hrs, Volume= 8,168 cf, Atten= 100%, Lag= 189.0 min
Primary = 0.03 cfs @ 6.11 hrs, Volume= 8,168 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=738.06' @ 6.11 hrs Surf.Area= 3,288 sf Storage= 10,092 cf
Flood Elev= 736.50' Surf.Area= 3,288 sf Storage=7,658 cf
Plug-Flow detention time= 2,277.7 min calculated for 8,168 cf(78% of inflow)
Center-of-Mass det. time= 2,254.3 min ( 2,459.7 -205.4 )
Volume Invert Avail.Storage Storage Description
#1A 733.00' 271 cf 8.42'W x 20.04'L x 5.50'H Field A
928 cf Overall - 250 cf Embedded = 678 cf x 40.0%Voids
#2A 733.75' 250 cf ADS_StormTech MC-3500 d +Cap x 2 Inside#1
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#36 733.00' 981 cf 8.42'W x 77.40'L x 5.50'H Field 6
3,583 cf Overall - 1,129 cf Embedded = 2,454 cf x 40.0% Voids
#46 733.75' 1,129 cf ADS_StormTech MC-3500 d +Cap x 10 Inside#3
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#5C 733.00' 893 cf 8.42'W x 70.23'L x 5.50'H Field C
3,251 cf Overall - 1,019 cf Embedded = 2,232 cf x 40.0% Voids
#6C 733.75' 1,019 cf ADS_StormTech MC-3500 d +Cap x 9 Inside#5
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#7D 733.00' 1,434 cf 15.58'W x 63.06'L x 5.50'H Field D
5,405 cf Overall - 1,819 cf Embedded = 3,586 cf x 40.0% Voids
#8D 733.75' 1,819 cf ADS_StormTech MC-3500 d +Cap x 16 Inside#7
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
16 Chambers in 2 Rows
Cap Storage= +14.9 cf x 2 x 2 rows = 59.6 cf
#9E 733.00' 715 cf 8.42'W x 55.89'L x 5.50'H Field E
2,587 cf Overall -799 cf Embedded = 1,788 cf x 40.0%Voids
#10E 733.75' 799 cf ADS_StormTech MC-3500 d +Cap x 7 Inside#9
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#11 F 733.00' 645 cf 15.58'W x 27.21'L x 5.50'H Field F
2,332 cf Overall -719 cf Embedded = 1,613 cf x 40.0%Voids
#12F 733.75' 719 cf ADS_StormTech MC-3500 d +Cap x 6 Inside#11
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
6 Chambers in 2 Rows

6 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Cap Storage= +14.9 cf x 2 x 2 rows = 59.6 cf
10,676 cf Total Available Storage
Storage Group A created with Chamber Wizard
Storage Group B created with Chamber Wizard
Storage Group C created with Chamber Wizard
Storage Group D created with Chamber Wizard
Storage Group E created with Chamber Wizard
Storage Group F created with Chamber Wizard
Device Routing Invert Outlet Devices (Turned on 1 times)
#1 Primary 731.30' 12.0" Round Outlet L= 10.0' Ke= 0.500
Inlet 1 Outlet Invert=731.30'1731.20' S=0.0100 7' Cc= 0.900
n= 0.013, Flow Area=0.79 sf
#2 Device 1 733.00' BayFilter Cartridges X 8.00 0.250" Diameter, C= 0.600
Inlet/Outlet Elev. =0.00'/731.30' Starts@733.00' Breaks@731.55'
#3 Device 2 734.25' StormTech to BayFilter 12.000" Diameter, C= 0.600
5.2' Long Tube, Hazen-Williams C= 130
Inlet/Outlet Elev. =734.25'/734.13'
Primary OutFlow Max=0.03 cfs @ 6.11 hrs HW=738.06' TW=0.00' (Dynamic Tailwater)
L1=Outlet (Passes 0.03 cfs of 9.46 cfs potential flow)
L2=BayFilter Cartridges (Orifice Controls 0.03 cfs @ 12.52 fps)
L3=StormTech to BayFilter (Passes 0.03 cfs of 7.38 cfs potential flow)
Pond 6D: 6 UGD
Hydrograph
■Inflow
8 i 764 its I ■Primary I
Inflow Area=24 ,163 sf
Peak Elegy=738.06'
Storage=1O,092 cf
6
.1
4
IL :
2
1%
+/JJJ//J/!JlIJJJJJ/!//lJJIJJJJ!/JIJJIJJJJ/JJ/!//lJJIJJJ///��rlri��iiiiJ%////
f]'f9: //
ir J� /////////////////////////////////////////////////////////////////////////////////////%
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 90 85 90 95 100 105 110 115 120
Time (hours)

6 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 6E: Overflow
Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 0°/0, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 6E: Overflow
Hydrograph
■Inflow
❑Primary I
cfs por
U
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)

6 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 6F: Total Discharge
Inflow Area = 249,163 sf, 0.00% Impervious, Inflow Depth = 0.39" for 1-inch event
Inflow = 0.03 cfs @ 6.11 hrs, Volume= 8,168 cf
Primary = 0.03 cfs @ 6.11 hrs, Volume= 8,168 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 6F: Total Discharge
Hydrograph
■_■• •■•__ ■Inflow
0-038_' .- -.-__ 0 Primary
0.036_ am .r/ MMM_
0.032_ A //l/// ////////// ��_�_
III
o-o2s
0.026_' o' •___0.022 p^ °-022=
I 0.02'
g 0.018'
LL 0.0167'
0.014
0-012
0 008
0.006
-004
0-°02—r` %
(30.00211
%%%%% %%//
0
0 5 10 15 20 25 30 35 40 45 50 55 60 65 TO 15 80 85 90 95 100 105 110 115 120
Time (hours)

1 -YEAR
ROUTING

<6A>
<6B)
6 Pre 6 Post AFS
Flow Splitter
N.
N.
6E
A �_____
Overflow
6 UGD \ i
6F
Total Discharge
Subcat Reach 'on. Iti Routing Diagram for 6 ADSPrepared by{enter your company name here), Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

6 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 6A: 6 Pre
Runoff = 0.49 cfs @ 12.23 hrs, Volume= 4,417 cf, Depth= 0.21"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 2.861 55 Wooded
* 2.861 61 Grass
5.722 58 Weighted Average
5.722 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 6A: 6 Pre
Hydrograph
•Runoff
0 5i.,/ I o-49 cFs 1
Type II 24-h r
01/ 1-yr Rainfall=2.80"
0.41 / Runoff Area=5.722 ac
0351 Runoff Volume=4,417 cf
031/ % Runoff Dep h=0.21"
g 0-25iZ Tc=20.0 min
0-21/ CN=58
0.15
005�
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 9D 95 100 105 110 115 120
Time (hours)

6 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 6B: 6 Post
Runoff = 15.64 cfs @ 11.96 hrs, Volume= 31,001 cf, Depth= 1.49"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 3.899 98 Impervious
* 1.823 61 Grass
5.722 86 Weighted Average
1.823 31.86% Pervious Area
3.899 68.14% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 6B: 6 Post
Hydrograph
17� ■Runoff
5✓ ® Type II 24-h r
14•r 1-yr Rainfall=2.80"
13' Runoff Area=5.722 ac
12i
11V Runoff Volume=31,001 cf
N 1D: Runoff Depth=1.49"
9=
o s-. Tc=5.0 min
LT_ /
CN=86
3=• 1
2- 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)

6 ADS Type II 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond FS: Flow Spliiter
Inflow Area = 249,250 sf, 68.14% Impervious, Inflow Depth = 1.49" for 1-yr event
Inflow = 15.64 cfs @ 11.96 hrs, Volume= 31,001 cf
Outflow = 15.64 cfs @ 11.96 hrs, Volume= 31,001 cf, Atten= 0°/0, Lag= 0.0 min
Primary = 12.76 cfs @ 11.92 hrs, Volume= 13,966 cf
Secondary= 10.07 cfs @ 12.02 hrs, Volume= 17,035 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=739.10' @ 12.02 hrs
Flood Elev= 743.25'
Device Routing Invert Outlet Devices
#1 Primary 734.00' 18.0" Round Low Flow L= 12.3' Ke= 0.500
Inlet/Outlet Invert= 734.00'1733.92' S= 0.0065 '1' Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Secondary 733.50' 30.0" Round High Flow L= 71.5' Ke= 0.500
Inlet 1 Outlet Invert= 733.50'1731.20' S= 0.0322 '1' Cc= 0.900
n= 0.012, Flow Area= 4.91 sf
#3 Device 2 738.25' Weir Wall, Cv=2.62 (C= 3.28)
Elev. (feet) 738.25 742.75 742.75
Width (feet) 4.00 4.00 0.00
Primary OutFlow Max=10.42 cfs @ 11.92 hrs HW=738.36' TW=736.86' (Dynamic Tailwater)
L1=Low Flow (Inlet Controls 10.42 cfs @ 5.90 fps)
Secondary OutFlow Max=9.07 cfs @ 12.02 hrs HW=739.03' TW=0.00' (Dynamic Tailwater)
t-2=High Flow (Passes 9.07 cfs of 48.91 cfs potential flow)
L3=Weir Wall (Weir Controls 9.07 cfs @ 2.90 fps)

6 ADS Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond FS: Flow Splitter
Hydrograph
0 Inflow
I15.64�I Outflow
,5d 6 �g Inflow Area=249,250 sf :PrimSecary
17 •
16 Peak Elegy=739.10T
15
14 l;-:
13
12 i, '
11 „
m 1.
u 9
o
7 /
6
5
4 0
3
241,
f ��
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 95 90 95 100 105 110 115 120
Time (hours)

6 ADS Type II 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCADO 10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 6D: 6 UGD
Inflow Area = 249,250 sf, 68.14% Impervious, Inflow Depth = 0.67" for 1-yr event
Inflow = 12.76 cfs @ 11.92 hrs, Volume= 13,966 cf
Outflow = 12.17 cfs @ 12.00 hrs, Volume= 11,674 cf, Atten= 5°/0, Lag=4.9 min
Primary = 12.17 cfs @ 12.00 hrs, Volume= 11,674 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev= 859,798.01' @ 12.00 hrs Surf.Area= 3,288 sf Storage= 10,676 cf
Flood Elev= 736.50' Surf.Area= 3,288 sf Storage= 7,658 cf
Plug-Flow detention time= 2,137.1 min calculated for 11,671 cf(84% of inflow)
Center-of-Mass det. time= 2,098.0 min ( 2,837.6 -739.6 )
Volume Invert Avail.Storage Storage Description
#1A 733.00' 271 cf 8.42'W x 20.04'L x 5.50'H Field A
928 cf Overall - 250 cf Embedded = 678 cf x 40.0%Voids
#2A 733.75' 250 cf ADS_StormTech MC-3500 d +Cap x 2 Inside#1
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#36 733.00' 981 cf 8.42'W x 77.40'L x 5.50'H Field 6
3,583 cf Overall - 1,129 cf Embedded = 2,454 cf x 40.0% Voids
#46 733.75' 1,129 cf ADS_StormTech MC-3500 d +Cap x 10 Inside#3
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#5C 733.00' 893 cf 8.42'W x 70.23'L x 5.50'H Field C
3,251 cf Overall - 1,019 cf Embedded = 2,232 cf x 40.0% Voids
#6C 733.75' 1,019 cf ADS_StormTech MC-3500 d +Cap x 9 Inside#5
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#7D 733.00' 1,434 cf 15.58'W x 63.06'L x 5.50'H Field D
5,405 cf Overall - 1,819 cf Embedded = 3,586 cf x 40.0% Voids
#8D 733.75' 1,819 cf ADS_StormTech MC-3500 d +Cap x 16 Inside#7
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
16 Chambers in 2 Rows
Cap Storage= +14.9 cf x 2 x 2 rows = 59.6 cf
#9E 733.00' 715 cf 8.42'W x 55.89'L x 5.50'H Field E
2,587 cf Overall -799 cf Embedded = 1,788 cf x 40.0%Voids
#10E 733.75' 799 cf ADS_StormTech MC-3500 d +Cap x 7 Inside#9
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#11 F 733.00' 645 cf 15.58'W x 27.21'L x 5.50'H Field F
2,332 cf Overall -719 cf Embedded = 1,613 cf x 40.0%Voids
#12F 733.75' 719 cf ADS_StormTech MC-3500 d +Cap x 6 Inside#11
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
6 Chambers in 2 Rows

6 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Cap Storage= +14.9 cf x 2 x 2 rows = 59.6 cf
10,676 cf Total Available Storage
Storage Group A created with Chamber Wizard
Storage Group B created with Chamber Wizard
Storage Group C created with Chamber Wizard
Storage Group D created with Chamber Wizard
Storage Group E created with Chamber Wizard
Storage Group F created with Chamber Wizard
Device Routing Invert Outlet Devices
#1 Primary 731.30' 12.0" Round Outlet L= 10.0' Ke= 0.500
Inlet/Outlet Invert=731.30'1731.20' S=0.0100 '1' Cc= 0.900
n= 0.013, Flow Area=0.79 sf
#2 Device 1 733.00' BayFilter Cartridges X 8.00 0.250" Diameter, C= 0.600
Inlet/Outlet Elev. =0.00'1731.30' Starts@733.00' Breaks@731.55'
#3 Device 2 734.25' StormTech to BayFilter 12.000n Diameter, C= 0.600
5.2' Long Tube, Hazen-Williams C= 130
Inlet/Outlet Elev. =734.25'/734.13'
Primary OutFlow Max=12.17 cfs @ 12.00 hrs HW=859,795.24' TW=0.00' (Dynamic Tailwater)
L1=Outlet (Passes 12.17 cfs of 3,505.07 cfs potential flow)
L2=BayFilter Cartridges (Orifice Controls 12.17 cfs @ 4,462.79 fps)
L3=StormTech to BayFilter (Passes 12.17 cfs of 3,482.88 cfs potential flow)
Pond 6D: 6 UGD
Hydragraph
■Inflow
14= / I1a76ch I 0 PrimaryI
13 127 j Inflow Area 249,250 sf
■
12- f Peak Elev=859,798.01'
11 I/
1 D-
j Storage=10,676 cf
9
a.
3 6�
LL 6- f
5- //J
4
3
00
1- J/JJIJJ!!//!J!JJIJJJ!/J!!//lJJIJJJJJJJ/JJIJI//II////////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)

6 ADS Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here) Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 6E: Overflow
Inflow = 10.07 cfs a@ 12.02 hrs, Volume= 17,035 cf
Primary = 10.07 cfs @ 12.02 hrs, Volume= 17,035 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 6E: Overflow
Hydrograph
■Inflow
11� I1DD7cfs I 0 Primary
, 10.07 cis(/
1D�
u �
O
a 5 J
31 2
fl
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)

6 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/30/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 6F: Total Discharge
Inflow Area = 249,250 sf, 68.14% Impervious, Inflow Depth = 1.38" for 1-yr event
Inflow = 19.24 cfs @ 12.00 hrs, Volume= 28,709 cf
Primary = 19.24 cfs @ 12.00 hrs, Volume= 28,709 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 6F: Total Discharge
Hydrograph
■Inflow
21;/ I1924d I ❑Primary
20. / EEEZI Inflow Area=249,250 sf
19= /
17- `
16'.' /
15/
14-
13= /
12:
14 0 10-
a //
/
4
14
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)

DRAINAGE
BASIN #7

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #7
INTRODUCTION:
SUMMARY
Drainage basin#7 includes single family lots 239-257,304-315&319-332 in Phases 2B&3A,the future amenity
site and a portion of Garrison Grove Lane, Cairo Court, and Hamilton Park Drive. A pipe network system routes
runoff to a StormTech underground detention system and through a BayFilter vault which treats the water
quality volume. A flow splitter upstream of the underground detention allows higher flows to bypass the system.
DRAINAGE AREAS: (see drainage area map SW-3.0)
Predeveloped Drainage Area 9.04 acres
Postdeveloped Drainage Area 9.04 acres
SOIL TYPES: (see soils map)
Area(ac) Area(%) Soil Type Hydrologic Soil Group
9.04 100% B
Total 9.04 100%
CURVE NUMBER:
Predeveloped CN
Cover Type Area(ac) % CN Wtd. CN
Wooded 4.52 50% 55 27.50
Grass 4.52 50% 61 30.50
Total 9.04 58.00
Composite CN Use CN = 58
Postdeveloped CN
Cover Type Area(ac) % CN Wtd. CN
Impervious 5.27 58% 98 57.10
Grass 3.77 42% 61 25.46
Total 9.04 82.56
Composite CN Use CN = 83

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #7
HYDROLOGIC CALCULATIONS
Pre-developed Post-developed
Drainage area(DA) 9.04 ac. 9.04 ac
Cuve Number(CN) 58 83
Modified Curve Number(CN) n/a 93
Time of Concentration 0.33 hr. 0.08 hr.
Impervious Percentage 0% 58%
WATER QUALITY VOLUME (1°)
Volume must be released over a period of 2-5 days
Using the runoff volume calculations in the "Simple Method" :
Rv= 0.05+ .009(I)
Rv= 0.57 Win
WQv=(Design rainfall)(Rv)(Drainage Area)
WQv= 1" rainfall x Rv in/in x 1/12 in/ft x Da=
WQv= 0.433 ac-ft 75% WQv= 0.325 ac-ft
18,848 ft3 14,136 ft3
0.57 in 0.43 in
MODIFIED CURVE NUMBER
CNm= 1000/0 0+5P+10W Qv-10(WQv^2+1.25WQvP)^0.5}
P= rainfall, in inches(use1.0 inches)= 1.00
WQv= water quality volume, in inches= 0.43
CNm 92.6
CHANNEL PROTECTION VOLUME
Q= (P-0.2S)^21(P+0.8S)
Q= accumulated runoff volume, inches
P= accumulated rainfall(potential maximum runoff), inches 2.58 in
S= potential maximum soil retention, inches= 1000/CN-10 = 2.05 in
CN= SCS curve number
Q= 1.12 cfs
Compute Watershed Runoff
CPv= 0.841 ac-ft 50% CPv= 0.421 ac-ft
36,639 cu. Ft 18,320 cu. Ft
Channel Protection Volume Release Rate(1yr, 24 hr storm)
1.5 day
36 hour
Release= 0.283 cfs

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Impervious Calculations - Basin #7
Existing Impervious
Asphalt: 0 sf
Buildings: 0 sf
Concrete: 0 sf
Total Impervious Area: 0 sf
0.00 ac.
Drainage Area: 9.04
Impervious Percentage: 0%
Proposed Impervious
Asphalt: 57,640 sf
Buildings: 124,140 sf
Concrete: 47,650 sf
Total Impervious Area: 229,430 sf
5.27 ac.
Drainage Area: 9.04
Impervious Percentage: 58%

HYDROCAD
ROUTINGS

1 - INCH
ROUTING

•
Post CNm
1 (AP
Sand Filter
Su6Cat Reach 'on• Routing Diagram for 7 Sand Filter
Prepared by Center your company name here}, Printed 5/16/2022
HydroCAD'10.00-26 s/n 09478 fl 2020 HydroCAD Software Solutions LLC

7 Sand Filter Type II 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/16/2022
HydroCAD® 10.00-26 sin 09478 ©2020 HydroCAD Software Solutions LLC Page 2
Summary for Subcatchment 11 S: 7 Post CNm
Runoff = 8.77 cfs @ 2.97 hrs, Volume= 0.271 af, Depth= 0.36"
Runoff by SCS TR-20 method. UH=SCS, Weighted-CN. Time Span= 0.00-120.00 hrs. dt= 0.03 hrs
Type II 6-hr 1-inch Rainfall=1.0011
Area (ac) CN Description
* 9.040 91 Modified CN
9.040 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 11S: 7 Post CNm
Hydrograph
1 1 1 1 1 1 1 1 1 I
r ti
1 1 1 1 1 1 1 1 1 1 1 1 1
1 0 Runoff
y t t r
9.1 8.77 cfs I I , I I I ti t, t, ,r ti, t, ,t t- 1
1
JTTrTJ
THfr
TJTT
Y FI- "1 W-mer
'`
• JTJrTJ
1 1 1 1 1 1 1 1 1 1
✓ ti i r ti t
6� //" • 1 1 1 1 1 1 1 1 1 1 1Runp 1 A�ea= . 4 al
1 - 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
E
, 7 7 r Runoff-Vor�lm;e=0 7` alf-
5� 1 1 1 1 1 1 1 1 1 1 11 111 1
30 - 1 1 1 1 1 1 1 1 1 1 1 -R-tin-ci#f 1De ahT 1.36!'
4- / 1 1
E 1 1 T T 1 T T r r 1 T TLL=SR..4_0--i
3- UN Tr9J7
■
f- 1 7 T T f- iJti
1 T r T
1 l% , , , , , , , , , , , 1 1
o ' i���%///////////////////////////////////////////////////////////////////////////f///////////////
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)

7 Sand Filter Type 11 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/16/2022
HydroCAD© 10.00-26 s/n 09478 ©2020 HydroCAD Software Solutions LLC Page 4
Summary for Pond 10P: Sand Filter
Inflow Area = 9.040 ac, 0.00% Impervious, Inflow Depth = 0.36" for 1-inch event
Inflow = 8.77 cfs @ 2.97 hrs, Volume= 0.271 af
Outflow = 0.16 cfs @ 6.06 hrs, Volume= 0.271 af, Atten= 98%, Lag= 185.7 min
Primary = 0.16 cfs @ 6.06 hrs, Volume= 0.271 af
Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev= 741.64'@ 6.06 hrs Surf.Area= 5,291 sf Storage= 10,078 cf
Plug-Flow detention time=737.9 min calculated for 0.271 af(100% of inflow)
Center-of-Mass det. time=737.4 min ( 948.8 - 211.4 )
Volume Invert Avail.Storage Storage Description
#1 738.50' 25,121 cf Custom Stage Data (Prismatic)Listed below(Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
738.50 1,261 0 0
739.00 3,224 1,121 1,121
740.00 3,005 3,115 4,236
741.00 3,224 3,115 7,350
742.00 6,451 4,838 12,188
743.00 3,686 5,069 17,256
744.00 3,929 3,808 21,064
745.00 4,186 4,058 25,121
Device Routing Invert Outlet Devices
#1 Primary 736.50' 18.0" Round Culvert L= 37.0' Ke= 0.500
Inlet/ Outlet Invert= 736.50'/ 736.30' S= 0.0054 '/' Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1 738.50' Sand Filter
Elev. (feet) 738.50 739.00 740.00 741.00 742.00 743.00 744.00
745.00
❑isch. (cfs) 0.000 0.068 0.102 0.136 0.170 0.204 0.238 0.272
#3 Device 1 742.00' 12.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 744.00' 3.0" x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
#5 Secondary 744.25' Emergency Spillway, Cv= 2.62 (C= 3.28)
Head (feet) 0.00 0.75
Width (feet) 15.00 15.00

7 Sand Filter Type II 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/16/2022
HydroCADO 10.00-26 sin 09478 02020 HydroCAD Software Solutions LLC Page 5
Primary OutFlow Max=0.16 cfs @ 6.06 hrs HW=741.64' (Free Discharge)
L1=Culvert (Passes 0.16 cfs of 17.83 cfs potential flow)
3=Sand Filter (Custom Controls 0.16 cfs)
—3=Low Flow Orifice ( Controls 0.00 cfs)
—4=Grate Top ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=738.50' (Free Discharge)
5=Emergency Spillway( Controls 0.00 cfs)
Pond 10P: Sand Filter
Hydrograph
I I I II II I
I I I II II I
■Inflow
I I I I I I I I I I •Outflow
H- +-H + + + + +-kin oiN+ H ry iy
•
,r
Pik-EJiv,141-. '-
of + + + + + o#'21 -E =14MTl8-cf-
7�J
_ I I
• • , I I
N "
5f I I
Or ,
y r ti t r t t t t r t r y r y r
3�r I I I
I I I
2J.
01E cfs
0000,17
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)

7 Sand Filter Type 11 6-hr 1-inch Rainfall=1.00"
Prepared by {enter your company name here} Printed 5/16/2022
HydroCAD© 10.00-26 s/n 09478 ©2020 HydroCAD Software Solutions LLC Pace 6
Hydrograph for Pond 10P: Sand Filter
Time Inflow Storage Elevation Outflow Primary Secondary
(hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs)
0.00 0.00 0 738.50 0.00 0.00 0.00
3.00 7.89 4,413 740.06 0.10 0.10 0.00
6.00 0.27 10,060 741.64 0.16 0.16 0.00
9.00 0.00 8,489 741.31 0.15 0.15 0.00
12.00 0.00 6,982 740.89 0.13 0.13 0.00
15.00 0.00 5,635 740.46 0.12 0.12 0.00
18.00 0.00 4,438 740.07 0.10 0.10 0.00
21.00 0.00 3,378 739.72 0.09 0.09 0.00
24.00 0.00 2,437 739.41 0.08 0.08 0.00
27.00 0.00 1,600 739.15 0.07 0.07 0.00
30.00 0.00 871 738.92 0.06 0.06 0.00
33.00 0.00 400 738.73 0.03 0.03 0.00
36.00 0.00 158 738.61 0.01 0.01 0.00
39.00 0.00 55 738.54 0.01 0.01 0.00
42.00 0.00 18 738.51 0.00 0.00 0.00
45.00 0.00 6 738.50 0.00 0.00 0.00
48.00 0.00 2 738.50 0.00 0.00 0.00
51.00 0.00 1 738.50 0.00 0.00 0.00
54.00 0.00 0 738.50 0.00 0.00 0.00
57.00 0.00 0 738.50 0.00 0.00 0.00
60.00 0.00 0 738.50 0.00 0.00 0.00
63.00 0.00 0 738.50 0.00 0.00 0.00
66.00 0.00 0 738.50 0.00 0.00 0.00
69.00 0.00 0 738.50 0.00 0.00 0.00
72.00 0.00 0 738.50 0.00 0.00 0.00
75.00 0.00 0 738.50 0.00 0.00 0.00
78.00 0.00 0 738.50 0.00 0.00 0.00
81.00 0.00 0 738.50 0.00 0.00 0.00
84.00 0.00 0 738.50 0.00 0.00 0.00
87.00 0.00 0 738.50 0.00 0.00 0.00
90.00 0.00 0 738.50 0.00 0.00 0.00
93.00 0.00 0 738.50 0.00 0.00 0.00
96.00 0.00 0 738.50 0.00 0.00 0.00
99.00 0.00 0 738.50 0.00 0.00 0.00
102.00 0.00 0 738.50 0.00 0.00 0.00
105.00 0.00 0 738.50 0.00 0.00 0.00
108.00 0.00 0 738.50 0.00 0.00 0.00
111.00 0.00 0 738.50 0.00 0.00 0.00
114.00 0.00 0 738.50 0.00 0.00 0.00
117.00 0.00 0 738.50 0.00 0.00 0.00
120.00 0.00 0 738.50 0.00 0.00 0.00

1 -YEAR
ROUTING

< 7B >
lost
1CAD
Sand Filter
Subcat Reach 'on.
It Routing Diagram for 7 Sand Filter
Prepared by{enter your company name here}, Printed 5/16/2022
HydroCAD®10.00-26 s/n 09478 ©2020 HydroCAD Software Solutions LLC

7 Sand Filter Type 1124-hr 1-yr Rainfall=2.80"
Prepared by {enter your company name here} Printed 5/16/2022
HydroCAD® 10.00-26 sin 09478 ©2020 HydroCAD Software Solutions LLC Page 2
Summary for Subcatchment 7B: 7 Post
Runoff = 21.49 cfs @ 11.96 hrs, Volume= 0.970 af, Depth= 1.29"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN. Time Span= 0.00-120.00 hrs. dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 5.267 98 Impervious
* 3.772 61 Grass
9.039 83 Weighted Average
3.772 41.73% Pervious Area
5.267 58.27% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 7B: 7 Post
Hydrograph
1 ti r r r r r --1--ti-- --r-- i r--r— r I 1 r r r r
24. 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 Runoff
22_ 4 21.49 cfs I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 7 r r r r 1 , r r r r r 1 1� 2�_. -
IT elt
,19= 1 1 1 1 1 1 I I I I I I 11 Rai#tfall#�del„-
it',, --I-- J 4 1 1 L L J J 1 1 1 L L 1 1 J 4 1 L L
17- �---- ;--;--7--r--E--�---- ; 7 7 rRian�rff-Iok eit='1-039-ae--
-� __1-- J 1 1 L L L J J 1 1 L L L 1 1 1 1 1 L L 15-. a= --I- 1 77 T El- , 1 1 T T T r r 1 1 1 7 T r r
-_ _J__1__1__L__L__L__I__J__J__1__1__L__ �}g 1 .�yJ /y�/97 —
J 13= 1 1 1 1 1 R ttn 11 1� t ■.Ii•�/1
3 12= r --1-- -7 r r r r r 1 -1 1 r r r r r 1 1 7-ryr t rr J�r-7-0 11' 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 T4��-ine -
LL ° r
, 1 1 1 1 1 1 1 1 1
9;
-I-- 1 1 T r El- I 1 1 T T r r r I I 1 1 =]V•!
8 1 ____ J 1 1 L L L J J 1 1 L L L 1 Ili L
i IIIIII III IIIIIIIIIII
77.; �__1__ yytrrr__1__yytt__r__r__r , 1 yyt__r__r_
---_ - 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1
I__ 1 1 1 J 1 1 1 11 1 1 1 1
3'� /-_1L L 1- L 1- L
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
4- 1 7 r r El- 1 1 r r r r r 1 1 1 7 T r r
3r' __-- 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1
I I I I I I I I I
1-
1:
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)

7 Sand Filter Type 1124-hr 7-yr Rainfall=2.80"
Prepared by {enter your company name here} Printed 5/16/2022
HydroCAD© 10.00-26 s/n 09478 ©2020 HydroCAD Software Solutions LLC Page 4
Summary for Pond 10P: Sand Filter
Inflow Area = 9.039 ac, 58.27% Impervious, Inflow Depth = 1.29" for 1-yr event
Inflow = 21.49 cfs @ 11.96 hrs, Volume= 0.970 of
Outflow = 2.79 cfs @ 12.25 hrs, Volume= 0.970 af, Atten= 87°/0, Lag= 17.1 min
Primary = 2.79 cfs @ 12.25 hrs, Volume= 0.970 af
Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev= 743.40'@ 12.25 hrs Surf.Area= 3,783 sf Storage= 18,741 cf
Plug-Flow detention time=474.9 min calculated for 0.969 af(100% of inflow)
Center-of-Mass det. time=475.4 min ( 1,310.6 - 835.2 )
Volume Invert Avail.Storage Storage Description
#1 738.50' 25,121 cf Custom Stage Data (Prismatic)Listed below(Recalc)
Elevation Surf.Area Inc.Store Cum.Store
(feet) (sq-ft) (cubic-feet) (cubic-feet)
738.50 1,261 0 0
739.00 3,224 1,121 1,121
740.00 3,005 3,115 4,236
741.00 3,224 3,115 7,350
742.00 6,451 4,838 12,188
743.00 3,686 5,069 17,256
744.00 3,929 3,808 21,064
745.00 4,186 4,058 25,121
Device Routing Invert Outlet Devices
#1 Primary 736.50' 18.0" Round Culvert L= 37.0' Ke= 0.500
Inlet/ Outlet Invert= 736.50'/ 736.30' S= 0.0054 '/' Cc= 0.900
n= 0.013, Flow Area= 1.77 sf
#2 Device 1 738.50' Sand Filter
Elev. (feet) 738.50 739.00 740.00 741.00 742.00 743.00 744.00
745.00
❑isch. (cfs) 0.000 0.068 0.102 0.136 0.170 0.204 0.238 0.272
#3 Device 1 742.00' 12.0"W x 6.0" H Vert. Low Flow Orifice C= 0.600
#4 Device 1 744.00' 3.0" x 3.0" Horiz. Grate Top X 16.00 columns
X 16 rows C= 0.600 in 48.0" x 48.0" Grate (100% open area)
Limited to weir flow at low heads
#5 Secondary 744.25' Emergency Spillway, Cv= 2.62 (C= 3.28)
Head (feet) 0.00 0.75
Width (feet) 15.00 15.00

7 Sand Filter Type 1124-hr 1-yr Rainfall=2.80"
Prepared by {enter your company name here} Printed 5/16/2022
HydroCAD® 10.00-26 sin 09478 ©2020 HydroCAD Software Solutions LLC Page 5
Primary OutFlow Max=2.79 cfs @ 12.25 hrs HW=743.40' (Free Discharge)
L1=Culvert (Passes 2.79 cfs of 21.10 cfs potential flow)
3=Sand Filter (Custom Controls 0.22 cfs)
—3=Low Flow Orifice (Orifice Controls 2.57 cfs @ 5.15 fps)
—4=Grate Top ( Controls 0.00 cfs)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=738.50' (Free Discharge)
ZS=Emergency Spillway( Controls 0.00 cfs)
Pond 10P: Sand Filter
Hydrograph
--1--r-7--r----T----r--r-7--r-7--r-7--r----1---1--r--1--7--r-r--
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 el Inflow
r/,-- - - - - - - - - ---------------
I11T----r--r7r11--r----Tr7r-7-- 10u1fIOW
iW- re03aE Se and
, 1 1 1 1 1 1 1 1 1 1 ry
• �, ____l/_J__L____11__L1__LJ__LJPLPF FI__1=_ _I-� t_
22i V 1 1 1 1 1"�a�,nk E Ili� 0 4
2{]-• , ,,' ,, I I 1 1 1 1 1 1 1 'Stkra e 8' 741'I I I I I I I I I I I I I cf
18 '. I I I I I I I I I I
1fY i r T r r r 7 r 7 r T r 1 1 r
1 1 1 1 1 1 1 1 1 1 1 1
' - "-- -1--r----T----7--r7--r7--r1--r----T----r----7--r-7--
Cr? _ • J
V I 1 1 1 1 1 1 1 1 1 1 1
30 12 I I1 I I I I I 1 1 1 1 1 1 1 1
____- _J__ ____1____1__L_1__L__It__ _J__ ____1____
LL 10= 1 1 1 1 1 1 1 1 1 1 L
1 t 1 1 1 1 1
I I I I I I I I I I I I I I I I
r _
8- r I 1
I I I I 1 1 1 1 1 1 I I I I I
. ,' ,'1279 cfs H--+----+----+--F-{--I----}-4--}----+----+----{--I-+--
4 ® i •
os°°r%/ //
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)

7 Sand Filter Type 1124-hr 1-yr Rainfall=2.80"
Prepared by {enter your company name here} Printed 5/16/2022
HydroCAD© 10.00-26 s/n 09478 ©2020 HydroCAD Software Solutions LLC Pace 6
Hydrograph for Pond 10P: Sand Filter
Time Inflow Storage Elevation Outflow Primary Secondary
(hours) (cfs) (cubic-feet) (feet) (cfs) (cfs) (cfs)
0.00 0.00 0 738.50 0.00 0.00 0.00
3.00 0.00 0 738.50 0.00 0.00 0.00
6.00 0.00 0 738.50 0.00 0.00 0.00
9.00 0.00 0 738.50 0.00 0.00 0.00
12.00 18.71 15,311 742.55 1.46 1.46 0.00
15.00 0.58 13,951 742.29 0.69 0.69 0.00
18.00 0.35 13,226 742.17 0.39 0.39 0.00
21.00 0.25 12,810 742.10 0.27 0.27 0.00
24.00 0.22 12,643 742.07 0.23 0.23 0.00
27.00 0.00 10,827 741.78 0.16 0.16 0.00
30.00 0.00 9,131 741.45 0.15 0.15 0.00
33.00 0.00 7,565 741.06 0.14 0.14 0.00
36.00 0.00 6,155 740.62 0.12 0.12 0.00
39.00 0.00 4,899 740.22 0.11 0.11 0.00
42.00 0.00 3,786 739.85 0.10 0.10 0.00
45.00 0.00 2,799 739.53 0.09 0.09 0.00
48.00 0.00 1,923 739.25 0.08 0.08 0.00
51.00 0.00 1,142 739.01 0.07 0.07 0.00
54.00 0.00 556 738.80 0.04 0.04 0.00
57.00 0.00 233 738.65 0.02 0.02 0.00
60.00 0.00 85 738.56 0.01 0.01 0.00
63.00 0.00 28 738.52 0.00 0.00 0.00
66.00 0.00 9 738.51 0.00 0.00 0.00
69.00 0.00 3 738.50 0.00 0.00 0.00
72.00 0.00 1 738.50 0.00 0.00 0.00
75.00 0.00 0 738.50 0.00 0.00 0.00
78.00 0.00 0 738.50 0.00 0.00 0.00
81.00 0.00 0 738.50 0.00 0.00 0.00
84.00 0.00 0 738.50 0.00 0.00 0.00
87.00 0.00 0 738.50 0.00 0.00 0.00
90.00 0.00 0 738.50 0.00 0.00 0.00
93.00 0.00 0 738.50 0.00 0.00 0.00
96.00 0.00 0 738.50 0.00 0.00 0.00
99.00 0.00 0 738.50 0.00 0.00 0.00
102.00 0.00 0 738.50 0.00 0.00 0.00
105.00 0.00 0 738.50 0.00 0.00 0.00
108.00 0.00 0 738.50 0.00 0.00 0.00
111.00 0.00 0 738.50 0.00 0.00 0.00
114.00 0.00 0 738.50 0.00 0.00 0.00
117.00 0.00 0 738.50 0.00 0.00 0.00
120.00 0.00 0 738.50 0.00 0.00 0.00

DRAINAGE
BASIN #8

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #8
INTRODUCTION:
SUMMARY
Drainage basin#8 includes single family lots 201-210,258-274, 300-306,316-38&333-335 in Phases 2A, 2B&
3A, and a portion of Twin River Drive, Hamilton Park Drive, and Larragan Drive.A pipe network system routes
runoff to a StormTech underground detention system and through a BayFilter vault which treats the water
quality volume. A flow splitter upstream of the underground detention allows higher flows to bypass the system.
DRAINAGE AREAS: (see drainage area map SW-3.0)
Predeveloped Drainage Area 6.65 acres
Postdeveloped Drainage Area 6.65 acres
SOIL TYPES: (see soils map)
Area(ac) Area(%) Soil Type Hydrologic Soil Group
6.65 100% B
Total 6.65 100%
CURVE NUMBER:
Predeveloped CN
Cover Type Area(ac) % CN Wtd. CN
Wooded 3.33 50% 55 27.50
Grass 3.33 50% 61 30.50
Total 6.65 58.00
Composite CN Use CN = 58
Postdeveloped CN
Cover Type Area(ac) % CN Wtd. CN
Impervious 3.72 56% 98 54.82
Grass 2.93 44% 61 26.88
Total 6.65 81.70
'Composite CN Use CN = 82

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: Ibt Charlotte, NC 28205
REVISED: 08.03.20 Preliminary Calculations - Basin #8
HYDROLOGIC CALCULATIONS
Pre-developed Post-developed
Drainage area(DA) 6.65 ac. 6.65 ac
Cuve Number(CN) 58 82
Modified Curve Number(CN) n/a 92
Time of Concentration 0.33 hr. 0.08 hr.
Impervious Percentage 0% 56%
WATER QUALITY VOLUME (1°)
Volume must be released over a period of 2-5 days
Using the runoff volume calculations in the "Simple Method" :
Rv= 0.05+ .009(I)
Rv= 0.55 inlin
WQv=(Design rainfall)(Rv)(Drainage Area)
WQv= 1" rainfall x Rv in/in x 1/12 in/ft x Da=
WQv= 0.307 ac-ft 75% WQv= 0.230 ac-ft
13,368 ft3 10,026 ft3
0.55 in 0.42 in
MODIFIED CURVE NUMBER
CNm= 1000/0 0+5P+10W Qv-10(WQv^2+1.25WQvP)^0.5}
P= rainfall, in inches(use1.0 inches)= 1.00
WQv= water quality volume, in inches= 0.42
CNm 92.3
CHANNEL PROTECTION VOLUME
Q= (P-0.2S)^21(P+0.8S)
Q= accumulated runoff volume, inches
P= accumulated rainfall(potential maximum runoff), inches 2.58 in
S= potential maximum soil retention, inches= 1000/CN-10 = 2.20 in
CN= SCS curve number
Q= 1.06 cfs
Compute Watershed Runoff
CPv= 0.586 ac-ft 50% CPv= 0.293 ac-ft
25,535 cu. Ft 12,767 cu. Ft
Channel Protection Volume Release Rate(1yr, 24 hr storm)
1.5 day
36 hour
Release= 0.197 cfs

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 12.20.18 P.M.: lbt Charlotte, NC 28205
REVISED: 08.03.20 Impervious Calculations - Basin #8
Existing Impervious
Asphalt: sf
Buildings: sf
Concrete: sf
Total Impervious Area: 0 sf
0.00 ac.
Drainage Area: 6.65
Impervious Percentage: 0%
Proposed Impervious
Asphalt: 47,935 sf
Buildings: 83,866 sf
Concrete: 30,340 sf
Total Impervious Area: 162,141 sf
3.72 ac.
Drainage Area: 6.65
Impervious Percentage: 56%

HYDROCAD
ROUTINGS

1 - INCH
ROUTING

<8C>
8 Post 1Nm AFS
.
F w Splitter MH .
8E
AND �N____
Overflow
StormTech & Bay . ter
#8
8F
Total Discharge
Subcat Reach 'on. Iti Routing Diagram for 8 ADSPrepared by{enter your company name here), Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

8 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 8C: 8 Post CNm
Runoff = 7.20 cfs @ 2.97 hrs, Volume= 0.223 af, Depth= 0.40"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 6-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 6.650 92 Modified CN
6.650 100.00°/% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, post To
Subcatchment 8C: 8 Post CNm
Hydrograph
81
■Runoff
I Aso
7 Type II
6-hr
6
1-inch Rainfall=1.00"
5 / Runoff Area=6.650 ac
13 Runoff Volume=0.223 af
3 4
LL Runoff Depth=0.40"
3 Tc=5.0 min
2 , CN=92
1
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)

8 ADS Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond FS: Flow Spliiter MH
Inflow Area = 6.650 ac, 0.00% Impervious, Inflow Depth = 0.40" for 1-inch event
Inflow = 7.20 cfs @ 2.97 hrs, Volume= 0.223 of
Outflow = 7.20 cfs @ 2.97 hrs, Volume= 0.223 af, Atten= 0%, Lag= 0.0 min
Primary = 7.20 cfs @ 2.97 hrs, Volume= 0.223 of
Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0.000 of
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=755.25' @ 6.09 hrs
Flood Elev= 758.25'
Device Routing Invert Outlet Devices
#1 Primary 751.50' 18.0" Round Low Flow L= 8.1' Ke= 0.500
Inlet 1 Outlet Invert= 751.50'!751.45' S= 0.0062 '!' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area= 1.77 sf
#2 Secondary 751.00' 30.0" Round High Flow L= 31.3' Ke= 0.500
Inlet/Outlet Invert=751.00'/749.50' S= 0.0479 '1' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area=4.91 sf
#3 Device 2 755.50' Weir Wall, Cv=2.62 (C= 3.28)
Elev. (feet) 755.50 757.75 757.75
Width (feet) 5.00 5.00 0.00
Primary OutFlow Max=7.15 cfs @ 2.97 hrs HW=753.23' TW=752.02' (Dynamic Tailwater)
L1=Low Flow (Barrel Controls 7.15 cfs @ 4.41 fps)
Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=751.00' TW=0.00' (Dynamic Tailwater)
t-2=High Flow ( Controls 0.00 cfs)
L3=Weir Wall ( Controls 0.00 cfs)

8 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond FS: Flow Splitter MH
Hydrograph
0 Inflow
I 720cfs L Outflow
8
,� Inflow Area=6.650 ac MI Seccondary
- Peak Elegy=755.25'
7_
6�
5-'
F
4-'
u_ - '
3-
- � 1
2
•
1 •
/�
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)

8 ADS Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 8D: StormTech & BayFilter#8
Inflow Area = 6.650 ac, 0.00% Impervious, Inflow Depth = 0.40" for 1-inch event
Inflow = 7.20 cfs @ 2.97 hrs, Volume= 0.223 of
Outflow = 0.04 cfs @ 6.12 hrs, Volume= 0.192 af, Atten= 100%, Lag= 188.8 min
Primary = 0.04 cfs @ 6.12 hrs, Volume= 0.192 of
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=755.26' @ 6.12 hrs Surf.Area= 3,094 sf Storage= 9,345 cf
Flood Elev= 755.88' Surf.Area= 3,094 sf Storage= 10,116 cf
Plug-Flow detention time= 2,356.7 min calculated for 0.192 of(86% of inflow)
Center-of-Mass det. time= 2,339.3 min ( 2,548.7 -209.5 )
Volume Invert Avail.Storage Storage Description
#1A 750.38' 874 cf 8.42'W x 69.23'L x 5.50'H Field A
3,205 cf Overall - 1,019 cf Embedded = 2,185 cf x 40.0% Voids
#2A 751.13' 1,019 cf ADS_StormTech MC-3500 d +Cap x 9 Inside#1
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#36 750.38' 874 cf 8.42'W x 69.23'L x 5.50'H Field 6
3,205 cf Overall - 1,019 cf Embedded = 2,185 cf x 40.0% Voids
#46 751.13' 1,019 cf ADS_StormTech MC-3500 d +Cap x 9 Inside#3
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#5C 750.38' 1,561 cf 22.75'W x 47.72'L x 5.50'H Field C
5,971 cf Overall -2,069 cf Embedded = 3,902 cf x 40.0% Voids
#6C 751.13' 2,069 cf ADS_StormTech MC-3500 d +Cap x 18 Inside#5
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
18 Chambers in 3 Rows
Cap Storage= +14.9 cf x 2 x 3 rows = 89.4 cf
#7D 750.38' 519 cf 8.42'W x 40.55'L x 5.50'H Field D
1,877 cf Overall - 580 cf Embedded = 1,298 cf x 40.0%Voids
#8D 751.13' 580 cf ADS_StormTech MC-3500 d +Cap x 5 Inside#7
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#9E 750.38' 430 cf 8.42'W x 33.38'L x 5.50'H Field E
1,545 cf Overall -470 cf Embedded = 1,076 cf x 40.0%Voids
#10E 751.13' 470 cf ADS_StormTech MC-3500 d +Cap x 4 Inside#9
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#11 F 750.38' 341 cf 8.42'W x 26.21'L x 5.50'H Field F
1,213 cf Overall - 360 cf Embedded = 854 cf x 40.0% Voids
#12F 751.13' 360 cf ADS_StormTech MC-3500 d +Cap x 3 Inside#11
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf

8 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
10,116 cf Total Available Storage
Storage Group A created with Chamber Wizard
Storage Group B created with Chamber Wizard
Storage Group C created with Chamber Wizard
Storage Group D created with Chamber Wizard
Storage Group E created with Chamber Wizard
Storage Group F created with Chamber Wizard
Device Routing Invert Outlet Devices (Turned on 1 times)
#1 Primary 749.60' 12.0" Round 12" Outlet L= 13.5' Ke= 0.500
Inlet/Outlet Invert=749.60'/749.50' S=0.0074 '1' Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf
#2 Device 1 751.27' BayFilter X 9.00 0.250" Diameter, C= 0.600
Inlet/Outlet Elev. =0.00'/749.60' Starts@751.27' Breaks@749.85'
#3 Device 2 751.30' StormTech to BayFilter 12.000" Diameter, C= 0.600
4.6' Long Tube, Hazen-Williams C= 130
Inlet/Outlet Elev. =751.30'/751.20'
Primary OutFlow Max=0.04 cfs @ 6.12 hrs HW=755.26' TW=0.00' (Dynamic Tailwater)
L1=12" Outlet (Passes 0.04 cfs of 8.59 cfs potential flow)
L2=BayFilter (Orifice Controls 0.04 cfs @ 11.45 fps)
L3=StormTech to BayFilter (Passes 0.04 cfs of 7.45 cfs potential flow)
Pond 8D: StormTech & BayFilter#8
Hydrograph
■Inflow
8 zsa ■Primary
7 0 Inflow Area=6.650 ac
Peak Elev=755.26'
6
Storage=9,,345 cf
5
L1
3 4
0
LL
3
2
1
o /r %/////////////////////////////////////////////////////////////////
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)

8 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 8E: Overflow
Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af
Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten= 0%, Lag=0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 8E: Overflow
Hydrograph
■Inflow
0 Primary I
U
IT-
cfs
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)

8 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 8F: Total Discharge
Inflow Area = 6.650 ac, 0.00% Impervious, Inflow Depth = 0.35" for 1-inch event
Inflow = 0.04 cfs @ 6.12 hrs, Volume= 0.192 of
Primary = 0.04 cfs @ 6.12 hrs, Volume= 0.192 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 8F: Total Discharge
Hydrograph
■Inflow
0.038 Lu-ua
❑Primary
0.034, // //// -
0 032_ ; 1111111tillo.o :0.026_ ,ifO. y /// ///// /0.02 'S 0.018= ' ,--- 1
LI 0.016'
0.012✓ 04:/
0.01
0.00/6 liii. ,. 7:,,
0.00
0.002= 10 (..../7... .... . ( 7/4 //... /
0 50 15 20 25 3035 40 45 50 55 60 65 TO T5 80 85....90. 95 100 105 110 115 120
Time (hours)

1 -YEAR
ROUTING

<8A>
<8B >
8 Pre 8 Post AFS
F w Splitter MH .
NA
8E
/81:\ ---\____
Overflow
StormTech & Bay . ter
#8
8F
Total Discharge
Subcat Reach 'on. Iti Routing Diagram for 8 ADSPrepared by{enter your company name here), Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

8 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 8A: 8 Pre
Runoff = 0.57 cfs @ 12.23 hrs, Volume= 0.118 af, Depth= 0.21"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 3.327 55 Wooded
* 3.327 61 Grass
6.654 58 Weighted Average
6.654 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
20.0 Direct Entry, pre To
Subcatchment 8A: 8 Pre
Hydrograph
IN Runoff
06' Iosr cps I
0.55J Type II 24-h r
0-5 1-yr Rainfall=2.80"
Runoff Area=6.654 ac
0-4" Runoff Volume=0.118 of
Runoff Depth=0.21"
0-3;// Tc=20.0 min
02 "/ j CN=58
0-15� �'
0.05Y
0 e,fr� .:.., ' ��� ���� �� ����1/
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)

8 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 86: 8 Post
Runoff = 15.04 cfs @ 11.96 hrs, Volume= 0.678 af, Depth= 1.22"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 3.720 98 Impervious
* 2.930 61 Grass
6.650 82 Weighted Average
2.930 44.06% Pervious Area
3.720 55.94% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post To
Subcatchment 8B: 8 Post
Hydrograph
/ ■Runoff
16
15 O4 ds
15= /
13J Type II 24-h r
1i / 1-yr Rainfall=2.80"
12z Runoff Area=6.650 ac
11= Runoff Volume=0.678 of
1D='
97 Runoff Depth=1.22"
3 ✓
II = r 7= Tc=5.0 min
"
6✓ CN=82
5i
4J
/
2� !
0 5 10 15 20 25 30 35 40 45 50 55 66 65 70 75 80 85 90 95 100 105 110 115 120
Time (hours)

8 ADS Type !I 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond FS: Flow Spliiter MH
Inflow Area = 6.650 ac, 55.94% Impervious, Inflow Depth = 1.22" for 1-yr event
Inflow = 15.04 cfs @ 11.96 hrs, Volume= 0.678 of
Outflow = 15.04 cfs @ 11.96 hrs, Volume= 0.678 af, Atten= 0%, Lag= 0.0 min
Primary = 12.96 cfs @ 11.94 hrs, Volume= 0.285 of
Secondary= 6.41 cfs @ 12.05 hrs, Volume= 0.393 of
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=756.04' @ 12.05 hrs
Flood Elev= 758.25'
Device Routing Invert Outlet Devices
#1 Primary 751.50' 18.0" Round Low Flow L= 8.1' Ke= 0.500
Inlet 1 Outlet Invert= 751.50'!751.45' S= 0.0062 '!' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area= 1.77 sf
#2 Secondary 751.00' 30.0" Round High Flow L= 31.3' Ke= 0.500
Inlet/Outlet Invert=751.00'/749.50' S= 0.0479 '!' Cc= 0.900
n= 0.012 Concrete pipe, finished, Flow Area=4.91 sf
#3 Device 2 755.50' Weir Wall, Cv=2.62 (C= 3.28)
Elev. (feet) 755.50 757.75 757.75
Width (feet) 5.00 5.00 0.00
Primary OutFlow Max=10.92 cfs @ 11.94 hrs HW=755.64' TW=753.99' (Dynamic Tailwater)
L1=Low Flow (Inlet Controls 10.92 cfs @ 6.18 fps)
Secondary OutFlow Max=5.81 cfs @ 12.05 hrs HW=756.00' TW=0.00' (Dynamic Tailwater)
t-2=High Flow (Passes 5.81 cfs of 45.78 cfs potential flow)
L3=Weir Wall (Weir Controls 5.81 cfs @ 2.32 fps)

8 ADS Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond FS: Flow Splitter MH
Hydrograph
0 Inflow
15.04 crs Outflow
15.11
= Inflow Area=6.650 ac :Secondary
15_ Peak EIev=756.04'
129 els
14-
12� NIP
11:
m 10-
a /
a 7? 6.41ds 0
6- I5- 11/
2 �FJ/!lJIJJF!//IJJ/JJF/!/!lJIJJ/FJ/!!J/JJF!//IJJ/JJF/F/IJ!!JJ////lIfJJJF///!//
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)

8 ADS Type II 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 8D: StormTech & BayFilter#8
Inflow Area = 6.650 ac, 55.94% Impervious, Inflow Depth = 0.51" for 1-yr event
Inflow = 12.96 cfs @ 11.94 hrs, Volume= 0.285 of
Outflow = 9.70 cfs @ 12.03 hrs, Volume= 0.254 af, Atten= 25%, Lag= 5.5 min
Primary = 9.70 cfs @ 12.03 hrs, Volume= 0.254 of
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=431,644.40' @ 12.03 hrs Surf.Area= 3,094 sf Storage= 10,116 cf
Flood Elev= 755.88' Surf.Area= 3,094 sf Storage= 10,116 cf
Plug-Flow detention time= 2,380.7 min calculated for 0.254 of(89% of inflow)
Center-of-Mass det. time= 2,338.5 min ( 3,089.5 -751.1 )
Volume Invert Avail.Storage Storage Description
#1A 750.38' 874 cf 8.42'W x 69.23'L x 5.50'H Field A
3,205 cf Overall - 1,019 cf Embedded = 2,185 cf x 40.0% Voids
#2A 751.13' 1,019 cf ADS_StormTech MC-3500 d +Cap x 9 Inside#1
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#36 750.38' 874 cf 8.42'W x 69.23'L x 5.50'H Field 6
3,205 cf Overall - 1,019 cf Embedded = 2,185 cf x 40.0% Voids
#46 751.13' 1,019 cf ADS_StormTech MC-3500 d +Cap x 9 Inside#3
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#5C 750.38' 1,561 cf 22.75'W x 47.72'L x 5.50'H Field C
5,971 cf Overall -2,069 cf Embedded = 3,902 cf x 40.0% Voids
#6C 751.13' 2,069 cf ADS_StormTech MC-3500 d +Cap x 18 Inside#5
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
18 Chambers in 3 Rows
Cap Storage= +14.9 cf x 2 x 3 rows = 89.4 cf
#7D 750.38' 519 cf 8.42'W x 40.55'L x 5.50'H Field D
1,877 cf Overall - 580 cf Embedded = 1,298 cf x 40.0%Voids
#8D 751.13' 580 cf ADS_StormTech MC-3500 d +Cap x 5 Inside#7
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#9E 750.38' 430 cf 8.42'W x 33.38'L x 5.50'H Field E
1,545 cf Overall -470 cf Embedded = 1,076 cf x 40.0%Voids
#10E 751.13' 470 cf ADS_StormTech MC-3500 d +Cap x 4 Inside#9
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf
#11 F 750.38' 341 cf 8.42'W x 26.21'L x 5.50'H Field F
1,213 cf Overall - 360 cf Embedded = 854 cf x 40.0% Voids
#12F 751.13' 360 cf ADS_StormTech MC-3500 d +Cap x 3 Inside#11
Effective Size= 70.4"W x 45.0"H => 15.33 sf x 7.17'L = 110.0 cf
Overall Size= 77.0"W x 45.0"H x 7.50'L with 0.33' Overlap
Cap Storage= +14.9 cf x 2 x 1 rows = 29.8 cf

8 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
10,116 cf Total Available Storage
Storage Group A created with Chamber Wizard
Storage Group B created with Chamber Wizard
Storage Group C created with Chamber Wizard
Storage Group D created with Chamber Wizard
Storage Group E created with Chamber Wizard
Storage Group F created with Chamber Wizard
Device Routing Invert Outlet Devices
#1 Primary 749.60' 12.0" Round 12" Outlet L= 13.5' Ke= 0.500
Inlet/Outlet Invert=749.60'/749.50' S=0.0074 '1' Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf
#2 Device 1 751.27' BayFilter X 9.00 0.250n Diameter, C= 0.600
Inlet/Outlet Elev. =0.00'1749.60' Starts@751.27' Breaks@749.85'
#3 Device 2 751.30' StormTech to BayFilter 12.000n Diameter, C= 0.600
4.6' Long Tube, Hazen-Williams C= 130
Inlet/Outlet Elev. =751.30'/751.20'
Primary OutFlow Max=9.70 cfs @ 12.03 hrs HW=431,640.61' TW=0.00' (Dynamic Tailwater)
L1=12"Outlet (Passes 9.70 cfs of 2,482.38 cfs potential flow)
L2=BayFilter (Orifice Controls 9.70 cfs @ 3,160.66 fps)
L3=StormTech to BayFilter (Passes 9.70 cfs of 2,467.74 cfs potential flow)
Pond 8D: StormTech & BayFilter#8
Hydrograph
■Inflow
14: ma`s I ❑Primary
13: Inflow Area=6.650 ac
127." Peak Ele =431,644.40'
11= p. Storage=10,116 cf
1D:
9
13 a=
0 7=
LL 6.
4-
2- 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)

8 ADS Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 8E: Overflow
Inflow = 6.41 cfs @ 12.05 hrs, Volume= 0.393 af
Primary = 6.41 cfs @ 12.05 hrs, Volume= 0.393 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 8E: Overflow
Hyd rag raph
Inflow
7 / 6.41 ds I ■Primary I
l6.41 z _ r
6 /7-
51
4-i
3-
1-
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)

8 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 8F: Total Discharge
Inflow Area = 6.650 ac, 55.94% Impervious, Inflow Depth = 1.17" for 1-yr event
Inflow = 15.16 cfs @ 12.03 hrs, Volume= 0.647 of
Primary = 15.16 cfs @ 12.03 hrs, Volume= 0.647 af, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 8F: Total Discharge
Hydrograph
/ ■Inflow
t516crs 0 Primary
16=, 75.76 Inflow Area=6 65A ac
15i/
14
13V
12V
11V
1567891
D' /:71;
g_ 11111111111111111
a=
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)

DRAINAGE
BASIN #9

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 05.30.19 P.M.: lbt Charlotte, NC 28205
REVISED: PRELIMINARY CALCULATIONS
INTRODUCTION:
SUMMARY
Drainage basin#9 includes single family lots 211-238,274-302&307-309 in Phases 2A, 3A&3B,and a portion
of Twin River Drive, River Park Lane, Garrison Grove Lane, Alaina Court, Keyser Drive, and Larragan Drive.A
pipe network system routes runoff to a StormTech underground detention system and through a BayFilter vault
which treats the water quality volume.A flow splitter upstream of the underground detention allows higher
flows to bypass the system.
DRAINAGE AREAS: (see drainage area map SW-3.0)
Predeveloped Drainage Area 11.20 acres
Postdeveloped Drainage Area 11.20 acres
SOIL TYPES: (see soils map)
Area(ac) Area(%) Soil Type Hydrologic Soil Group
11.20 100% B
,Total 11.20 100%
CURVE NUMBER:
Predeveloped CN
Cover Type Area(ac) % CN Wtd. CN
Wooded 5.60 50% 55 27.50
Grass 5.60 50% 61 30.50
Total 11.20 58.00
(Composite CN Use ON = 58
Postdeveloped CN
Cover Type Area(ac) % CN Wtd. CN
Impervious 6.49 58% 98 56.80
Grass 4.71 42% 61 25.64
Total 11.20 82.44
Composite CN Use CN = 82

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 05.30.19 P.M.: Ibt Charlotte, NC 28205
REVISED: PRELIMINARY CALCULATIONS
HYDROLOGIC CALCULATIONS
Pre-developed Post-developed
Drainage area(DA) 11.20 ac. 11.20 ac
Cuve Number(CN) 58 82
Modified Curve Number(CN) n/a 93
Time of Concentration 0.33 hr. 0.08 hr.
Impervious Percentage 0% 58%
WATER QUALITY VOLUME (1°)
Volume must be released over a period of 2-5 days
Using the runoff volume calculations in the "Simple Method" :
Rv= 0.05+ .009(I)
Rv= 0.57 Win
WQv=(Design rainfall)(Rv)(Drainage Area)
WQv= 1" rainfall x Rv in/in x 1/12 in/ft x Da=
WQv= 0.533 ac-ft 75% WQv = 0.400 ac-ft
23,238 ft3 17,428 ft3
0.57 in 0.43 in
MODIFIED CURVE NUMBER
CNm= 1000/0 0+5P+10W Qv-10(WQv^2+1.25WQvP)^0.5}
P= rainfall, in inches(use1.0 inches)= 1.00
WQv= water quality volume, in inches= 0.43
CNm 92.6
CHANNEL PROTECTION VOLUME
Q= (P-0.2S)^21(P+0.8S)
Q= accumulated runoff volume, inches
P= accumulated rainfall(potential maximum runoff), inches 2.58 in
S= potential maximum soil retention, inches= 1000/CN-10 = 2.20 in
CN= SCS curve number
Q= 1.06 cfs
Compute Watershed Runoff
CPv= 0.987 ac-ft 50% CPv= 0.493 ac-ft
42,973 cu. Ft 21,487 cu. Ft
Channel Protection Volume Release Rate(1yr, 24 hr storm)
1.5 day
36 hour
Release= 0.332 cfs

Rivercross Urban Design Partners
JOB NO.: 18-001 BY: udp 1318-E6 Central Avenue
DATE: 05.30.19 P.M.: Ibt _ Charlotte, NC 28205
REVISED: IMPERVIOUS CALCULATIONS
Existing Impervious
Building sf
Concrete Parking sf
Asphalt sf
Sidewalk sf
Total Impervious Area: 0 sf
0.00 ac.
Drainage Area: 11.20
Impervious Percentage: 0%
[Proposed Impervious
Asphalt: 7E,090 sf
Buildings: 149,655 sf
Concrete: 56,388 sf
Total Impervious Area: 282,733 sf
6.49 ac.
Drainage Area: 11.20
Impervious Percentage: 58%

HYDROCAD
ROUTINGS

1 - INCH
ROUTING

<9C>
9 Post N m AFS
.
Flow Splitter N
9E
/9ND ....---\__
Overflow
9 UGD
9F
Total Discharge
Subcat Reach 'on. Iti Routing Diagram for 9 ADSPrepared by{enter your company name here), Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

9 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 9C: 9 Post CNm
Runoff = 13.49 cfs @ 2.97 hrs, Volume= 18,311 cf, Depth= 0.45"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 6-hr 1-inch Rainfall=1.00"
Area (ac) CN Description
* 11.200 93 Modified CN
11.200 100.00°/° Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
5.0 Direct Entry, post To
Subcatchment 9C: 9 Post CNm
Hydrograph
15
r ■Runoff
141 1349 cls
13= Type II
12 / 6-hr
1-inch Rainfall=1.00"
1°- Runoff Area=11.200 ac
/
Runoff:Volu me=18,311 cf
o �= Runoff Depth=0.45"
LL
651 Tc=5.0 mini
5 CN=93
3
2
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)

9 ADS Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond FS: Flow Spliiter
Inflow Area = 487,872 sf, 0.00% Impervious, Inflow Depth = 0.45" for 1-inch event
Inflow = 13.49 cfs @ 2.97 hrs, Volume= 18,311 cf
Outflow = 13.49 cfs @ 2.97 hrs, Volume= 18,311 cf, Atten= 0°/0, Lag= 0.0 min
Primary = 2.42 cfs @ 2.96 hrs, Volume= 3,972 cf
Secondary= 11.07 cfs @ 2.97 hrs, Volume= 14,339 cf
Tertiary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=735.08' @ 6.10 hrs
Flood Elev= 739.25'
Device Routing Invert Outlet Devices
#1 Primary 730.25' 8.0" Round Priming Line L= 50.0' Ke= 0.500
Inlet 1 Outlet Invert= 730.25'!729.67' S= 0.0116 '!' Cc= 0.900
n= 0.013, Flow Area= 0.35 sf
#2 Secondary 731.00' 18.0" Round Low Flow L= 11.1' Ke= 0.500
Inlet 1 Outlet Invert=731.00'!730.00' S= 0.0901 '!' Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf
#3 Tertiary 730.25' 36.0" Round High Flow L= 23.9' Ke= 0.500
Inlet/Outlet Invert= 730.25'!730.00' S= 0.010571 Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 7.07 sf
#4 Device 3 735.25' Weir Wall, Cv=2.62 (C= 3.28)
Elev. (feet) 735.25 738.75 738.75
Width (feet) 5.75 5.75 0.00
Primary OutFlow Max=2.27 cfs @ 2.96 hrs HW=733.38' TW=730.63' (Dynamic Tailwater)
L1=Priming Line (Outlet Controls 2.27 cfs @ 6.49 fps)
Secondary OutFlow Max=10.98 cfs @ 2.97 hrs HW=733.42' TW=730.70' (Dynamic Tailwater)
t-2=Low Flow (Inlet Controls 10.98 cfs @ 6.21 fps)
Tertiary OutFlow Max=0.00 cfs @ 0.00 hrs HW=730.25' TW=0.00' (Dynamic Tailwater)
L3=High Flow ( Controls 0.00 cfs)
Z-4=Weir Wall ( Controls 0.00 cfs)

9 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond FS: Flow Splitter
Hydrograph
•Inflow
173-49 c I 0 Outflow
71349ds Inflow Area=48T,8(2 st o0 Secondary
15. Paair Firm= 35.08 _■Tertiary
14=
13='
11-117 crs
12i'
11='
10J/l
N 9a:
- / piti
LL 6 xi[ I
4- 7'
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)

9 ADS Type !I 6-hr 1-inch Rainfall=1.00"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 9D: 9 UGD
Inflow Area = 487,872 sf, 0.00% Impervious, Inflow Depth = 0.45" for 1-inch event
Inflow = 13.49 cfs @ 2.97 hrs, Volume= 18,311 cf
Outflow = 0.07 cfs @ 6.11 hrs, Volume= 14,404 cf, Atten= 100%, Lag= 188.8 min
Primary = 0.07 cfs @ 6.11 hrs, Volume= 14,404 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=735.09' @ 6.11 hrs Surf.Area=4,377 sf Storage= 17,631 cf
Flood Elev= 737.25' Surf.Area=4,377 sf Storage= 17,910 cf
Plug-Flow detention time= 2,204.1 min calculated for 14,401 cf(79% of inflow)
Center-of-Mass det. time= 2,181.5 min ( 2,389.0 -207.5 )
Volume Invert Avail.Storage Storage Description
#1A 728.50' 3,236 cf 19.42'W x 100.19'L x 6.75'H Field A
13,131 cf Overall - 5,041 cf Embedded = 8,090 cf x 40.0% Voids
#2A 729.25' 5,041 cf ADS_StormTech MC-4500 +Cap x 46 Inside#1
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap
46 Chambers in 2 Rows
Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf
#36 728.50' 1,020 cf 10.33'W x 55.92'L x 6.75'H Field B
3,900 cf Overall - 1,349 cf Embedded = 2,551 cf x 40.0% Voids
#46 729.25' 1,349 cf ADS_StormTech MC-4500 +Cap x 12 Inside#3
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap
Cap Storage= +35.7 cf x 2 x 1 rows = 71.4 cf
#5C 728.50' 1,475 cf 19.42'W x 43.84'L x 6.75'H Field C
5,746 cf Overall -2,060 cf Embedded = 3,686 cf x 40.0% Voids
#6C 729.25' 2,060 cf ADS_StormTech MC-4500 +Cap x 18 Inside#5
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap
18 Chambers in 2 Rows
Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf
#7D 728.50' 742 cf 10.33'W x 39.82'L x 6.75'H Field D
2,777 cf Overall - 923 cf Embedded = 1,854 cf x 40.0%Voids
#8D 729.25' 923 cf ADS_StormTech MC-4500 +Cap x 8 Inside#7
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap
Cap Storage= +35.7 cf x 2 x 1 rows = 71.4 cf
#9E 728.50' 463 cf 10.33'W x 23.72'L x 6.75'H Field E
1,654 cf Overall -497 cf Embedded = 1,157 cf x 40.0%Voids
#10E 729.25' 497 cf ADS_StormTech MC-4500 +Cap x 4 Inside#9
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap
Cap Storage= +35.7 cf x 2 x 1 rows = 71.4 cf
#11 F 728.50' 309 cf 10.33'W x 15.17'L x 6.75'H Field F
1,058 cf Overall -284 cf Embedded =773 cf x 40.0% Voids
#12F 729.25' 284 cf ADS_StormTech MC-4500 +Cap x 2 Inside#11
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap

9 ADS Type 11 6-hr I-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Cap Storage= +35.7 cf x 2 x 1 rows = 71.4 cf
#13 728.50' 510 cf 7.00'W x 27.00'L x 6.75'H Prismatoid
1,276 cf Overall x 40.0°/0 Voids
17,910 cf Total Available Storage
Storage Group A created with Chamber Wizard
Storage Group B created with Chamber Wizard
Storage Group C created with Chamber Wizard
Storage Group D created with Chamber Wizard
Storage Group E created with Chamber Wizard
Storage Group F created with Chamber Wizard
Device Routing Invert Outlet Devices (Turned on 1 times)
#1 Primary 728.00' 12.0" Round Outlet L= 9.1' Ke=0.500
Inlet/Outlet Invert=728.00'/727.95' S=0.0055 'P Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf
#2 Device 1 729.67' BayFilter Cartridges X 15.00 0.250" Diameter, C= 0.600
Inlet/Outlet Elev. =0.00'/728.00' Starts@729.67' Breaks@728.50'
#3 Device 2 730.00' StormTech to BayFilter 12.000" Diameter, C= 0.600
7.0' Long Tube, Hazen-Williams C= 130
Inlet/Outlet Elev. =730.00'/729.38'
Primary OutFlow Max=0.07 cfs @ 6.11 hrs HW=735.09' TW=0.00' (Dynamic Tailwater)
L1=Outlet (Passes 0.07 cfs of 9.71 cfs potential flow)
L2=BayFilter Cartridges (Orifice Controls 0.07 cfs @ 12.82 fps)
L3=StormTech to BayFilter (Passes 0.07 cfs of 8.63 cfs potential flow)
Pond 9D: 9 UGD
Hydrograph
■Inflow
15 )1349 cfs I 0 Primary
14i, Inflow Area=487,872 sf
12 %f Peak EIev=735.09'
11 Storage=17,631 cf
101/
9/
a- /
0 V
LL /
- �/
4V ,
3.
�
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)

9 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 9E: Overflow
Inflow = 0.00 cfs @ 0.00 hrs, Volume= 0 cf
Primary = 0.00 cfs @ 0.00 hrs, Volume= 0 cf, Atten= 0°/0, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 9E: Overflow
Hydrograph
■Inflow
❑Primary I
cfs por
U
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)

9 ADS Type 11 6-hr 7-inch Rainfall=1.00"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 9F: Total Discharge
Inflow Area = 487,872 sf, 0.00% Impervious, Inflow Depth = 0.35" for 1-inch event
Inflow = 0.07 cfs @ 6.11 hrs, Volume= 14,404 cf
Primary = 0.07 cfs @ 6.11 hrs, Volume= 14,404 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 9F: Total Discharge
Hyd rag raph
-■ ■- ■Inflow
_ CLOT cfs ❑Primary
0.07
0.06_ . /��/'r♦'♦�r�''e
tr
Op II I
',' -
47.1 f 0.o l•1• 1 ///////%%
0 D35t I. . 1
'frO
0.0254
0.02: 11
0.015-'
0.01: ■ • �
0.005�
0 r/ AprAirarr APPAPAPPAPPAPrAFAM'
0 5 10 15 20 25 30 35 40 45 50 55 60 65 TO 75 80 85 90 95 100 105 110 115 120
Time (hours)

1 -YEAR
ROUTING

< 9A>
< 9B >
9 Pre 9 Post
FS
Flow Splitter N
9E
/91:\ -----\---
Overflow
9 UGD
9F
Total Discharge
Subcat Reach on. Link Routing Diagram for 9ADS
Prepared by{enter your company name here), Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 0 2020 HydroCAD Software Solutions LLC

9 ADS Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 9A: 9 Pre
Runoff = 0.96 cfs @ 12.23 hrs, Volume= 8,645 cf, Depth= 0.21"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 5.600 55 Wooded
* 5.600 61 Grass
11.200 58 Weighted Average
11.200 100.00% Pervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ft/sec) (cfs)
20.0 Direct Entry, pre Tc
Subcatchment 9A: 9 Pre
Hydrograph
0 Runoff
1 a.ss
Type II 24-hr
1-yr Rainfall=2.80"
Runoff Area=11.200 ac
Runoff Volume=8,645 cf
Runoff Depth=0.21"
LL
Tc=20.0 min
CN=58
0
� �Ar■arl//
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)

9 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Subcatchment 96: 9 Post
Runoff = 25.33 cfs @ 11.96 hrs, Volume= 49,741 cf, Depth= 1.22"
Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Type II 24-hr 1-yr Rainfall=2.80"
Area (ac) CN Description
* 6.490 98 Impervious
* 4.710 61 Grass
11.200 82 Weighted Average
4.710 42.05% Pervious Area
6.490 57.95% Impervious Area
Tc Length Slope Velocity Capacity Description
(min) (feet) (ft/ft) (ftlsec) (cfs)
5.0 Direct Entry, post Tc
Subcatchment 9B: 9 Post
Hydrograph
28, ■Runoff
26-/ 25 3s crs
24- Type II 24-hr
22_ / 1-yr Rainfall=2.80"
20-' Runoff Area=11.200 ac
19 Runoff Volume=49,741 cf
16Y Runoff Depth=1.22"
14J
Tc=5.0 min
12-
10=/ CN=82
a�
6-
41
2=f % r
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)

9 ADS Type II 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 fl 2020 HydroCAD Software Solutions LLC
Summary for Pond FS: Flow Spliiter
Inflow Area = 487,872 sf, 57.95% Impervious, Inflow Depth = 1.22" for 1-yr event
Inflow = 25.33 cfs @ 11.96 hrs, Volume= 49,741 cf
Outflow = 25.33 cfs @ 11.96 hrs, Volume= 49,741 cf, Atten= 0°/0, Lag= 0.0 min
Primary = 2.74 cfs @ 11.92 hrs, Volume= 7,738 cf
Secondary= 16.44 cfs @ 11.93 hrs, Volume= 28,375 cf
Tertiary = 7.91 cfs @ 11.98 hrs, Volume= 13,628 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=735.81' @ 11.98 hrs
Flood Elev= 739.25'
Device Routing Invert Outlet Devices
#1 Primary 730.25' 8.0" Round Priming Line L= 50.0' Ke= 0.500
Inlet 1 Outlet Invert= 730.25'!729.67' S= 0.0116 '!' Cc= 0.900
n= 0.013, Flow Area= 0.35 sf
#2 Secondary 731.00' 18.0" Round Low Flow L= 11.1' Ke= 0.500
Inlet 1 Outlet Invert=731.00'!730.00' S= 0.0901 '!' Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.77 sf
#3 Tertiary 730.25' 36.0" Round High Flow L= 23.9' Ke= 0.500
Inlet/Outlet Invert= 730.25'!730.00' S= 0.010571 Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 7.07 sf
#4 Device 3 735.25' Weir Wall, Cv=2.62 (C= 3.28)
Elev. (feet) 735.25 738.75 738.75
Width (feet) 5.75 5.75 0.00
Primary OutFlow Max=2.49 cfs @ 11.92 hrs HW=735.44' TW=732.13' (Dynamic Tailwater)
L1=Priming Line (Outlet Controls 2.49 cfs @ 7.13 fps)
Secondary OutFlow Max=15.13 cfs @ 11.93 hrs HW=735.54' TW=732.38' (Dynamic Tailwater)
t-2=Low Flow (Inlet Controls 15.13 cfs @ 8.56 fps)
Tertiary OutFlow Max=7.55 cfs @ 11.98 hrs HW=735.79' TW=0.00' (Dynamic Tailwater)
L3=High Flow (Passes 7.55 cfs of 68.44 cfs potential flow)
Z-4=Weir Wall (Weir Controls 7.55 cfs @ 2.41 fps)

9 ADS Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Pond FS: Flow Splitter
Hydrograph
•Inflow
0 Outflow
InflowArea=487,872 sf 00 Secondary
287 Peak Elegy=735.81' ■Tertiary
26=/11
24/
22- •.
20= A
16.44 crs
18:
16.
3 14-
o
12 ,-
10:
8' A
6
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)

9 ADS Type II 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 s/n 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Pond 9D: 9 UGD
Inflow Area = 487,872 sf, 57.95% Impervious, Inflow Depth = 0.89" for 1-yr event
Inflow = 19.34 cfs @ 11.92 hrs, Volume= 36,113 cf
Outflow = 12.85 cfs @ 12.06 hrs, Volume= 32,206 cf, Atten= 34%, Lag= 8.1 min
Primary = 12.85 cfs @ 12.06 hrs, Volume= 32,206 cf
Routing by Dyn-Stor-Ind method, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Peak Elev=273,128.40' @ 12.06 hrs Surf.Area= 4,377 sf Storage= 17,910 cf
Flood Elev= 737.25' Surf.Area=4,377 sf Storage= 17,910 cf
Plug-Flow detention time= 1,325.6 min calculated for 32,206 cf(89% of inflow)
Center-of-Mass det. time= 1,270.9 min ( 2,096.4 - 825.5 )
Volume Invert Avail.Storage Storage Description
#1A 728.50' 3,236 cf 19.42'W x 100.19'L x 6.75'H Field A
13,131 cf Overall - 5,041 cf Embedded = 8,090 cf x 40.0% Voids
#2A 729.25' 5,041 cf ADS_StormTech MC-4500 +Cap x 46 Inside#1
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap
46 Chambers in 2 Rows
Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf
#36 728.50' 1,020 cf 10.33'W x 55.92'L x 6.75'H Field B
3,900 cf Overall - 1,349 cf Embedded = 2,551 cf x 40.0% Voids
#46 729.25' 1,349 cf ADS_StormTech MC-4500 +Cap x 12 Inside#3
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap
Cap Storage= +35.7 cf x 2 x 1 rows = 71.4 cf
#5C 728.50' 1,475 cf 19.42'W x 43.84'L x 6.75'H Field C
5,746 cf Overall -2,060 cf Embedded = 3,686 cf x 40.0% Voids
#6C 729.25' 2,060 cf ADS_StormTech MC-4500 +Cap x 18 Inside#5
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap
18 Chambers in 2 Rows
Cap Storage= +35.7 cf x 2 x 2 rows = 142.8 cf
#7D 728.50' 742 cf 10.33'W x 39.82'L x 6.75'H Field D
2,777 cf Overall - 923 cf Embedded = 1,854 cf x 40.0%Voids
#8D 729.25' 923 cf ADS_StormTech MC-4500 +Cap x 8 Inside#7
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap
Cap Storage= +35.7 cf x 2 x 1 rows = 71.4 cf
#9E 728.50' 463 cf 10.33'W x 23.72'L x 6.75'H Field E
1,654 cf Overall -497 cf Embedded = 1,157 cf x 40.0%Voids
#10E 729.25' 497 cf ADS_StormTech MC-4500 +Cap x 4 Inside#9
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap
Cap Storage= +35.7 cf x 2 x 1 rows = 71.4 cf
#11 F 728.50' 309 cf 10.33'W x 15.17'L x 6.75'H Field F
1,058 cf Overall -284 cf Embedded =773 cf x 40.0% Voids
#12F 729.25' 284 cf ADS_StormTech MC-4500 +Cap x 2 Inside#11
Effective Size= 90.4"W x 60.0"H => 26.46 sf x 4.03'L = 106.5 cf
Overall Size= 100.0"W x 60.0"H x 4.33'L with 0.31' Overlap

9 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCADO 10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Cap Storage= +35.7 cf x 2 x 1 rows = 71.4 cf
#13 728.50' 510 cf 7.00'W x 27.00'L x 6.75'H Prismatoid
1,276 cf Overall x 40.0°/0 Voids
17,910 cf Total Available Storage
Storage Group A created with Chamber Wizard
Storage Group B created with Chamber Wizard
Storage Group C created with Chamber Wizard
Storage Group D created with Chamber Wizard
Storage Group E created with Chamber Wizard
Storage Group F created with Chamber Wizard
Device Routing Invert Outlet Devices
#1 Primary 728.00' 12.0" Round Outlet L= 9.1' Ke=0.500
Inlet/Outlet Invert=728.00'/727.95' S=0.0055 'P Cc= 0.900
n= 0.013 Corrugated PE, smooth interior, Flow Area= 0.79 sf
#2 Device 1 729.67' BayFilter Cartridges X 15.00 0.250" Diameter, C= 0.600
Inlet/Outlet Elev. =0.00'1728.00' Starts@729.67' Breaks@728.50'
#3 Device 2 730.00' StormTech to BayFilter 12.000" Diameter, C= 0.600
7.0' Long Tube, Hazen-Williams C= 130
Inlet/Outlet Elev. =730.00'/729.38'
Primary OutFlow Max=12.85 cfs @ 12.06 hrs HW=273,127.90' TW=0.00' (Dynamic Tailwater)
L1=Outlet (Passes 12.85 cfs of 1,973.73 cfs potential flow)
L2=BayFilter Cartridges (Orifice Controls 12.85 cfs @ 2,513.03 fps)
L3=StormTech to BayFilter (Passes 12.85 cfs of 1,955.48 cfs potential flow)
Pond 9D: 9 UGD
Hydrograph
■Inflow
21 ❑Primary
20i Inflow Area=487,872 sf
19- /
18i Peak EIev=273,128.40'
17-
16- Storage=17,910 cf
15
14- 12_85 ds
13
u 12-/
11=
10
LL /
of
/
6
t
//"„ r
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)

9 ADS Type 11 24-hr 1-yr Rainfall=2.8O"
Prepared by{enter your company name here) Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 9E: Overflow
Inflow = 7.91 cfs a@ 11.98 hrs, Volume= 13,628 cf
Primary = 7.91 cfs @ 11.98 hrs, Volume= 13,628 cf, Atten= 0%, Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 9E: Overflow
Hyd rag raph
■Inflow
7.91 ds l ■Primary
7 97 cis
7-
6�
, 5
LL 4 /
3i/./ I
17
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)

9 ADS Type 11 24-hr 1-yr Rainfall=2.80"
Prepared by{enter your company name here} Printed 7/31/2020
HydroCAD®10.00-26 sin 09103 ©2020 HydroCAD Software Solutions LLC
Summary for Link 9F: Total Discharge
Inflow Area = 487,872 sf, 57.95% Impervious, Inflow Depth = 1.13" for 1-yr event
Inflow = 16.17 cfs @ 12.06 hrs, Volume= 45,834 cf
Primary = 16.17 cfs @ 12.06 hrs, Volume= 45,834 cf, Atten= 0%. Lag= 0.0 min
Primary outflow = Inflow, Time Span= 0.00-120.00 hrs, dt= 0.03 hrs
Link 9F: Total Discharge
Hydrograph
■Inflow
18. Prima
17_ I Inflow Area-487,872 sf Primary
16570
15y14:
V 13
12-/
11=
19
3 9V o
LL a=
6
5; /
41
,//
/ f
• r
1= %//i Ae
_%/////////////////////////////////////////////////////////////////// %%
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)