SW4240501_Design Calculations_20240819

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Watershed Model Schematic Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021
2 3
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CD Int vet
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Project: Old Hollow-REV.gpw Monday, 08/ 19/2024

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wvu. nvuvvon,ph Inflow Peak Outflow(ms) nvumsmpx
No. type hvu(s) oonx,|puon
(origin) 1-v, o-yr a-yr s-yr 10-yr os-yr so'v, Ion'v,
1 SC8Runon 0.245 3721 9.979 Pond 1'P,o'dev
2 SCSnunoK 6.921 17.52 30.10 Pond 1'PoatInflow
3 SC8Runon 11.02 26.04 4339 Pond u'PootInflow
4 nosonm|r z 0u94 6.618 21.84 Ponu1'Outflow
5 nosonm|r n 0.179 13.68 40.77 Ponuu'Outflow
0 Combine 4, 5 0.273 20.18 6258 PondCombino'Poot
r SCSnunoK 0.01e 0.559 1.520 Ponuc'pm'uev
8 Combine 1. 7 0.257 3.843 10.03 PondCombino'P"e
Pnoj. file: Old Ho||ow+REV.gpw Monday, U8/ 10/2024
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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 1
Pond 1-Pre-dev
Hydrograph type = SCS Runoff Peak discharge = 0.245 cfs
Storm frequency = 1 yrs Time to peak = 733 min
Time interval = 1 min Hyd. volume = 2,521 cuft
Drainage area = 3.680 ac Curve number = 57*
Basin Slope = 4.4 % Hydraulic length = 640 ft
Tc method = LAG Time of conc. (Tc) = 19.80 min
Total precip. = 2.80 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(0.150 x 98)+(3.530 x 55)]/3.680
Pond 1-Pre-dev
Q (cfs) Hyd. No. 1 -- 1 Year Q (cfs)
0.50 0.50
0.45 0.45
0.40 0.40
0.35 0.35
0.30 0.30
0.25 0.25
0.20 0.20
0.15 0.15
0.10 0.10
0.05 0.05
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 2
Pond 1-Post Inflow
Hydrograph type = SCS Runoff Peak discharge = 6.921 cfs
Storm frequency = 1 yrs Time to peak = 721 min
Time interval = 1 min Hyd. volume = 16,858 cuft
Drainage area = 4.140 ac Curve number = 80*
Basin Slope = 3.2 % Hydraulic length = 589 ft
Tc method = LAG Time of conc. (Tc) = 11.60 min
Total precip. = 2.80 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(2.140 x 98)+(2.000 x 61)]/4.140
Pond 1-Post Inflow
Q (cfs) Hyd. No. 2 -- 1 Year Q(cfs)
7.00 7.00
6.00 6.00
5.00 5.00
4.00 4.00
3.00 3.00
2.00 2.00
— —
1.00 1.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 3
Pond 2-Post Inflow
Hydrograph type = SCS Runoff Peak discharge = 11.02 cfs
Storm frequency = 1 yrs Time to peak = 722 min
Time interval = 1 min Hyd. volume = 29,720 cuft
Drainage area = 6.360 ac Curve number = 83*
Basin Slope = 4.5 % Hydraulic length = 1010 ft
Tc method = LAG Time of conc. (Tc) = 13.70 min
Total precip. = 2.80 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(3.720 x 98)+(2.640 x 61)]/6.360
Pond 2-Post Inflow
Q (cfs) Hyd. No. 3 -- 1 Year Q (cfs)
12.00 12.00
10.00 i - 10.00
8.00 - 8.00
6.00 - - 6.00
4.00 4.00
2.00 2.00
0.00 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3 Time (min)

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 4
Pond 1-Outflow
Hydrograph type = Reservoir Peak discharge = 0.094 cfs
Storm frequency = 1 yrs Time to peak = 1441 min
Time interval = 1 min Hyd. volume = 9,296 cuft
Inflow hyd. No. = 2 - Pond 1-Post Inflow Max. Elevation = 963.67 ft
Reservoir name = Wet Pond-1 Max. Storage = 13,082 cuft
Storage Indication method used.
Pond 1-Outflow
Q (cfs) Hyd. No. 4 -- 1 Year Q (cfs)
7.00 7.00
6.00 6.00
5.00 5.00
4.00 4.00
3.00 3.00
2.00 2.00
1.00 1.00
0.00 0.00
0 300 600 900 1200 1500 1800 2100 2400 2700 3000
Time (min)
Hyd No. 4 Hyd No. 2 111111111 Total storage used = 13,082 cuft

Pond Report 7
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Pond No. 1 - Wet Pond-1
Pond Data
Contours-User-defined contour areas.Conic method used for volume calculation.Begining Elevation=962.00 ft
Stage/Storage Table
Stage(ft) Elevation(ft) Contour area(sqft) Incr.Storage(cuft) Total storage(cuft)
0.00 962.00 6,865 0 0
1.00 963.00 7,924 7,387 7,387
1.10 963.10 8,033 798 8,185
2.00 964.00 9,063 7,688 15,873
4.00 966.00 11,506 20,518 36,391
Culvert/Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr] [A] [B] [C] [D]
Rise(in) = 18.00 1.25 1.50 0.00 Crest Len(ft) = 9.42 0.00 0.00 0.00
Span(in) = 18.00 1.25 1.50 0.00 Crest El.(ft) = 964.00 0.00 0.00 0.00
No.Barrels = 1 1 1 0 Weir Coeff. = 3.33 3.33 3.33 3.33
Invert El.(ft) = 954.00 962.00 963.10 0.00 Weir Type = 1 --- --- ---
Length(ft) = 149.00 1.00 1.00 0.00 Multi-Stage = Yes No No No
Slope(%) = 0.67 0.00 0.00 n/a
N-Value = .013 .013 .013 n/a
Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000(by Contour)
Multi-Stage = n/a Yes Yes No TW Elev.(ft) = 0.00
Note:CulverUorifice outflows are analyzed under inlet(ic)and outlet(oc)control. Weir risers checked for orifice conditions(ic)and submergence(s).
Stage(ft) Stage/Discharge Elev(ft)
4.00 966.00
3.00 965.00
2.00 964.00
1.00 963.00
0.00 I - 962.00
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 22.00 24.00
Total Q Discharge(cfs)

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 5
Pond 2-Outflow
Hydrograph type = Reservoir Peak discharge = 0.179 cfs
Storm frequency = 1 yrs Time to peak = 1222 min
Time interval = 1 min Hyd. volume = 17,065 cuft
Inflow hyd. No. = 3 - Pond 2-Post Inflow Max. Elevation = 944.48 ft
Reservoir name = Wet Pond - 2 Max. Storage = 22,500 cuft
Storage Indication method used.
Pond 2-Outflow
Q (cfs) Hyd. No. 5-- 1 Year Q (cfs)
12.00 12.00
10.00 10.00
8.00 I- 8.00
6.00 6.00
4.00 4.00
2.00 2.00
0.00 0.00
0 300 600 900 1200 1500 1800 2100 2400 2700 3000
Time (min)
Hyd No. 5 Hyd No. 3 111111111 Total storage used = 22,500 cuft

Pond Report 9
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Pond No. 2 - Wet Pond -2
Pond Data
Contours-User-defined contour areas.Conic method used for volume calculation.Begining Elevation=942.00 ft
Stage/Storage Table
Stage(ft) Elevation(ft) Contour area(sqft) Incr.Storage(cuft) Total storage(cuft)
0.00 942.00 7,457 0 0
1.00 943.00 8,621 8,031 8,031
1.60 943.60 9,302 5,375 13,406
2.00 944.00 9,768 3,813 17,219
4.00 946.00 12,232 21,952 39,171
6.00 948.00 14,922 27,107 66,278
Culvert/Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr] [A] [B] [C] [D]
Rise(in) = 24.00 1.50 2.00 0.00 Crest Len(ft) = 18.80 0.00 0.00 0.00
Span(in) = 24.00 1.50 2.00 0.00 Crest El.(ft) = 945.00 0.00 0.00 0.00
No.Barrels = 1 1 1 0 Weir Coeff. = 3.33 3.33 3.33 3.33
Invert El.(ft) = 933.00 942.00 943.70 0.00 Weir Type = 1 --- --- ---
Length(ft) = 48.00 1.00 1.00 0.00 Multi-Stage = Yes No No No
Slope(%) = 1.10 0.00 0.00 n/a
N-Value = .013 .013 .013 n/a
Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000(by Wet area)
Multi-Stage = n/a Yes No No TW Elev.(ft) = 0.00
Note:Culvert/Orifice outflows are analyzed under inlet(ic)and outlet(oc)control. Weir risers checked for orifice conditions(ic)and submergence(s).
Stage(ft) Stage/ Discharge Elev(ft)
6.00 948.00
5.00 947.00
4.00 946.00
3.00 r.°""m"n" ..n.nnm. - 945.00
2.00 944.00
1.00 943.00
•
0.00 f 942.00
0.00 6.00 12.00 18.00 24.00 30.00 36.00 42.00 48.00 54.00 60.00
Total Q Discharge(cfs)

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 6
Pond Combine-Post
Hydrograph type = Combine Peak discharge = 0.273 cfs
Storm frequency = 1 yrs Time to peak = 1311 min
Time interval = 1 min Hyd. volume = 26,361 cuft
Inflow hyds. = 4, 5 Contrib. drain. area = 0.000 ac
Pond Combine-Post
Q (cfs) Hyd. No. 6 -- 1 Year Q (cfs)
0.50 0.50
0.45 0.45
0.40 0.40
0.35 0.35
0.30 0.30
0.25 0.25
0.20 - 0.20
0.15 - 0.15
0.10 _ 0.10
0.05 0.05
0.00 - 0.00
0 300 600 900 1200 1500 1800 2100 2400 2700 3000
Time (min)
Hyd No. 6 Hyd No. 4 Hyd No. 5

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 7
Pond 2-Pre-dev
Hydrograph type = SCS Runoff Peak discharge = 0.019 cfs
Storm frequency = 1 yrs Time to peak = 723 min
Time interval = 1 min Hyd. volume = 210 cuft
Drainage area = 0.410 ac Curve number = 55
Basin Slope = 13.0 % Hydraulic length = 320 ft
Tc method = LAG Time of conc. (Tc) = 6.90 min
Total precip. = 2.80 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
Pond 2-Pre-dev
Q (cfs) Hyd. No. 7 -- 1 Year Q(cfs)
0.10 0.10
0.09 0.09
0.08 0.08
0.07 0.07
0.06 0.06
0.05 0.05
0.04 0.04
0.03 0.03
0.02 0.02
t‘ **'-----...
0.01 0.01
0.00 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 7 Time (min)

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 8
Pond Combine-Pre
Hydrograph type = Combine Peak discharge = 0.257 cfs
Storm frequency = 1 yrs Time to peak = 733 min
Time interval = 1 min Hyd. volume = 2,731 cuft
Inflow hyds. = 1, 7 Contrib. drain. area = 4.090 ac
Pond Combine-Pre
Q (cfs) Hyd. No. 8 -- 1 Year Q (cfs)
0.50 0.50
0.45 I 0.45
0.40 0.40
0.35 0.35
0.30 0.30
0.25 0.25
0.20 0.20
0.15 0.15
0.10 \ 0.10
0.05 - 0.05
i - 1
0.00 - • - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 8 Hyd No. 1 Hyd No. 7

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 1
Pond 1-Pre-dev
Hydrograph type = SCS Runoff Peak discharge = 9.979 cfs
Storm frequency = 100 yrs Time to peak = 726 min
Time interval = 1 min Hyd. volume = 32,512 cuft
Drainage area = 3.680 ac Curve number = 57*
Basin Slope = 4.4 % Hydraulic length = 640 ft
Tc method = LAG Time of conc. (Tc) = 19.80 min
Total precip. = 7.18 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(0.150 x 98)+(3.530 x 55)]/3.680
Pond 1-Pre-dev
Q (cfs) Hyd. No. 1 -- 100 Year Q (cfs)
10.00 - I 10.00
8.00 8.00
6.00 - 6.00
4.00 - 4.00
2.00 2.00
0.00 \ - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

14
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 2
Pond 1-Post Inflow
Hydrograph type = SCS Runoff Peak discharge = 30.10 cfs
Storm frequency = 100 yrs Time to peak = 720 min
Time interval = 1 min Hyd. volume = 74,354 cuft
Drainage area = 4.140 ac Curve number = 80*
Basin Slope = 3.2 % Hydraulic length = 589 ft
Tc method = LAG Time of conc. (Tc) = 11.60 min
Total precip. = 7.18 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(2.140 x 98)+(2.000 x 61)]/4.140
Pond 1-Post Inflow
Q (cfs) Hyd. No. 2 -- 100 Year Q (cfs)
35.00 - 35.00
30.00 30.00
25.00 25.00
20.00 20.00
15.00 15.00
10.00 10.00
5.00 5.00
J
0.00 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

15
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 3
Pond 2-Post Inflow
Hydrograph type = SCS Runoff Peak discharge = 43.39 cfs
Storm frequency = 100 yrs Time to peak = 722 min
Time interval = 1 min Hyd. volume = 120,002 cuft
Drainage area = 6.360 ac Curve number = 83*
Basin Slope = 4.5 % Hydraulic length = 1010 ft
Tc method = LAG Time of conc. (Tc) = 13.70 min
Total precip. = 7.18 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(3.720 x 98)+(2.640 x 61)]/6.360
Pond 2-Post Inflow
Q (cfs) Hyd. No. 3 -- 100 Year Q (cfs)
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 - — 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 3 Time (min)

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 4
Pond 1-Outflow
Hydrograph type = Reservoir Peak discharge = 21.84 cfs
Storm frequency = 100 yrs Time to peak = 725 min
Time interval = 1 min Hyd. volume = 65,576 cuft
Inflow hyd. No. = 2 - Pond 1-Post Inflow Max. Elevation = 964.90 ft
Reservoir name = Wet Pond-1 Max. Storage = 25,110 cuft
Storage Indication method used.
Pond 1-Outflow
Q (cfs) Hyd. No. 4 -- 100 Year Q (cfs)
35.00 35.00
30.00 30.00
25.00 25.00
20.00 20.00
15.00 15.00
10.00 10.00
5.00 5.00
0.00 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 4 Hyd No. 2 111111111 Total storage used = 25,110 cuft

17
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday, 08/19/2024
Hyd. No. 5
Pond 2-Outflow
Hydrograph type = Reservoir Peak discharge = 40.77 cfs
Storm frequency = 100 yrs Time to peak = 724 min
Time interval = 1 min Hyd. volume = 105,111 cuft
Inflow hyd. No. = 3 - Pond 2-Post Inflow Max. Elevation = 945.75 ft
Reservoir name = Wet Pond - 2 Max. Storage = 36,377 cuft
Storage Indication method used.
Pond 2-Outflow
Q (cfs) Hyd. No. 5 -- 100 Year Q (cfs)
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 5 — Hyd No. 3 TTTTTT II Total storage used = 36,377 cuft

18
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 6
Pond Combine-Post
Hydrograph type = Combine Peak discharge = 62.58 cfs
Storm frequency = 100 yrs Time to peak = 724 min
Time interval = 1 min Hyd. volume = 170,687 cuft
Inflow hyds. = 4, 5 Contrib. drain. area = 0.000 ac
Pond Combine-Post
Q (cfs) Hyd. No. 6 -- 100 Year Q (cfs)
70.00 70.00
60.00 60.00
50.00 50.00
40.00 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 — 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 6 Hyd No. 4 Hyd No. 5

19
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 7
Pond 2-Pre-dev
Hydrograph type = SCS Runoff Peak discharge = 1.520 cfs
Storm frequency = 100 yrs Time to peak = 719 min
Time interval = 1 min Hyd. volume = 3,249 cuft
Drainage area = 0.410 ac Curve number = 55
Basin Slope = 13.0 % Hydraulic length = 320 ft
Tc method = LAG Time of conc. (Tc) = 6.90 min
Total precip. = 7.18 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
Pond 2-Pre-dev
Q (cfs) Hyd. No. 7 -- 100 Year Q (cfs)
2.00 i 2.00
1.00 1.00
0.00 — • . 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 7 Time (min)

20
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2021 Monday,08/19/2024
Hyd. No. 8
Pond Combine-Pre
Hydrograph type = Combine Peak discharge = 10.63 cfs
Storm frequency = 100 yrs Time to peak = 725 min
Time interval = 1 min Hyd. volume = 35,761 cuft
Inflow hyds. = 1, 7 Contrib. drain. area = 4.090 ac
Pond Combine-Pre
Q (cfs) Hyd. No. 8 -- 100 Year Q (cfs)
12.00 12.00
10.00 - 10.00
8.00 - 8.00
6.00 - 6.00
4.00 4.00
2.00 2.00
0.00 - - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 8 Hyd No. 1 Hyd No. 7