SW5230901_Stormwater Report_20230919

1
Watershed Model Schematic Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
1 -Pre-Development A Post-Development A
4-Post-Development Bypags-Rre-Development B
7-Post-Development B
V
3-Wet Pond Routing 1
ipl
5-Combined Post-Development
Legend
Hyd. Origin Description
1 SCS Runoff Pre-Development A
2 SCS Runoff Post-Development A
3 Reservoir Wet Pond Routing
4 SCS Runoff Post-Development Bypass A
5 Combine Combined Post-Development
6 SCS Runoff Pre-Development B
7 SCS Runoff Post-Development B
Project: PrePost- Copy.gpw Thursday, 08/31 /2023

Pond No. 1 - Wet Pond Hydraflow Hydrographs Extension forAutodesk®Civil 3D®byAutodesk, Inc.v2023
— 4.00 Top of pond
Elev 460 00
— 3.00 Broad crested weir
16.00 ft Riser WeirB-Elev.459.00
WeirA-Elev.458.00
— 2.00
— 1.00
2.00 in orifice
= CulvB-Inv.456.50
Stage(ft) "(� `\`\`\`\ \ \ ettopi o pond
50
Section CulvA-90.8 LF of 18.0 in @ 0.55%
NTS 100-yr
10-yr
2-yr
1-yr
Inflow hydrograph=2.SCS Runoff-Post-Development A
Project: PrePost-Copy.gpw Thursday, 08/31 /2023

2
Hydrograph Return Period Recap Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
I
Hyd. Hydrograph Inflow Peak Outflow(cfs) Hydrograph
No. type hyd(s) Description
(origin) 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr
1 SCS Runoff 6.718 10.56 21.95 41.52 Pre-Development A
2 SCS Runoff 6.919 9.752 17.65 30.18 Post-Development A
3 Reservoir 2 0.545 2.864 13.87 21.77 Wet Pond Routing
4 SCS Runoff 1.679 2.641 5.488 10.38 Post-Development Bypass A
5 Combine 3,4 1.715 3.121 14.60 22.97 Combined Post-Development
6 SCS Runoff 2.585 3.608 6.462 10.93 Pre-Development B
7 SCS Runoff 2.140 3.133 5.985 10.69 Post-Development B
Proj. file: PrePost- Copy.gpw Thursday, 08/31 /2023

3
Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph
No. type flow interval Peak volume hyd(s) elevation strge used Description
(origin) (cfs) (min) (min) (cuft) (ft) (cuft)
1 SCS Runoff 6.718 2 722 18,963 Pre-Development A
2 SCS Runoff 6.919 2 738 34,564 Post-Development A
3 Reservoir 0.545 2 896 32,424 2 458.02 22,568 Wet Pond Routing
4 SCS Runoff 1.679 2 722 4,741 Post-Development Bypass A
5 Combine 1.715 2 722 37,165 3,4 Combined Post-Development
6 SCS Runoff 2.585 2 722 6,777 Pre-Development B
7 SCS Runoff 2.140 2 720 4,976 Post-Development B
PrePost- Copy.gpw Return Period: 1 Year Thursday, 08/31 /2023

4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 1
Pre-Development A
Hydrograph type = SCS Runoff Peak discharge = 6.718 cfs
Storm frequency = 1 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 18,963 cuft
Drainage area = 7.200 ac Curve number = 71*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 10.10 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(6.903 x 70)+(0.297 x 89)]/7.200
Pre-Development A
Q (cfs) Hyd. No. 1 -- 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. 1 Time (min)

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TR55 Tc Worksheet
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. No. 1
Pre-Development A
Description A B C Totals
Sheet Flow
Manning's n-value = 0.050 0.011 0.011
Flow length (ft) = 300.0 0.0 0.0
Two-year 24-hr precip. (in) = 3.49 0.00 0.00
Land slope (%) = 3.54 0.00 0.00
Travel Time (min) = 7.47 + 0.00 + 0.00 = 7.47
Shallow Concentrated Flow
Flow length (ft) = 412.65 0.00 0.00
Watercourse slope (%) = 5.46 0.00 0.00
Surface description = Unpaved Paved Paved
Average velocity (ft/s) =3.77 0.00 0.00
Travel Time (min) = 1.82 + 0.00 + 0.00 = 1.82
Channel Flow
X sectional flow area (sqft) = 4.50 1.76 0.00
Wetted perimeter(ft) = 9.32 4.71 0.00
Channel slope (%) = 2.60 0.55 0.00
Manning's n-value = 0.015 0.015 0.015
Velocity (ft/s) =9.83
3.81
0.00
Flow length (ft) ({0})256.3 90.8 0.0
Travel Time (min) = 0.43 + 0.40 + 0.00 = 0.83
Total Travel Time, Tc 10.10 min

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 2
Post-Development A
Hydrograph type = SCS Runoff Peak discharge = 6.919 cfs
Storm frequency = 1 yrs Time to peak = 738 min
Time interval = 2 min Hyd. volume = 34,564 cuft
Drainage area = 8.100 ac Curve number = 80*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 38.30 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(4.470 x 89)+(3.630 x 70)]/8.100
Post-Development A
Q (cfs) Hyd. No. 2 -- 1 Year Q (cfs)
7.00 7.00
6.00 6.00
5.00 5.00
L
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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TR55 Tc Worksheet
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. No. 2
Post-Development A
Description A B C Totals
Sheet Flow
Manning's n-value = 0.410 0.011 0.011
Flow length (ft) = 269.4 0.0 0.0
Two-year 24-hr precip. (in) = 3.49 0.00 0.00
Land slope (%) = 3.76 0.00 0.00
Travel Time (min) = 35.99 + 0.00 + 0.00 = 35.99
Shallow Concentrated Flow
Flow length (ft) = 0.00 0.00 0.00
Watercourse slope (%) = 0.00 0.00 0.00
Surface description = Paved Paved Paved
Average velocity (ft/s) =0.00 0.00 0.00
Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00
Channel Flow
X sectional flow area (sqft) = 3.14 12.00 1.76
Wetted perimeter(ft) = 6.28 20.00 4.71
Channel slope (%) = 0.97 3.31 0.55
Manning's n-value = 0.015 0.015 0.015
Velocity (ft/s) =6.15
12.83
3.81
Flow length (ft) ({0})624.1 175.2 90.8
Travel Time (min) = 1.69 + 0.23 + 0.40 = 2.32
Total Travel Time, Tc 38.30 min

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 3
Wet Pond Routing
Hydrograph type = Reservoir Peak discharge = 0.545 cfs
Storm frequency = 1 yrs Time to peak = 896 min
Time interval = 2 min Hyd. volume = 32,424 cuft
Inflow hyd. No. = 2 - Post-Development A Max. Elevation = 458.02 ft
Reservoir name = Wet Pond Max. Storage = 22,568 cuft
Storage Indication method used.
Wet Pond Routing
Q (cfs) Hyd. No. 3 -- 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
0 600 1200 1800 2400 3000 3600 4200 4800 5400 6000
Time (min)
Hyd No. 3 Hyd No. 2 111111111 Total storage used = 22,568 cuft

Pond Report 9
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Pond No. 1 - Wet Pond
Pond Data
Contours-User-defined contour areas.Conic method used for volume calculation.Begining Elevation=456.50 ft
Stage/Storage Table
Stage(ft) Elevation(ft) Contour area(sqft) Incr.Storage(cuft) Total storage(cuft)
0.00 456.50 12,926 0 0
0.50 457.00 14,489 6,849 6,849
1.50 458.00 16,122 15,297 22,146
2.50 459.00 17,815 16,960 39,106
3.50 460.00 20,414 19,098 58,204
Culvert/Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr] [A] [B] [C] [D]
Rise(in) = 18.00 2.00 Inactive Inactive Crest Len(ft) = 16.00 20.00 Inactive Inactive
Span(in) = 18.00 2.00 20.00 0.00 Crest El.(ft) = 458.00 459.00 458.00 0.00
No.Barrels = 1 1 1 0 Weir Coeff. = 3.33 2.60 3.33 3.33
Invert El.(ft) = 452.50 456.50 457.00 0.00 Weir Type = 1 Broad Rect ---
Length(ft) = 90.78 0.00 0.00 0.00 Multi-Stage = Yes No No No
Slope(%) = 0.55 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 Yes 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)
4.00 460.50
3.00 459.50
2.00 458.50
1.00 457.50
0.00 456.50
0.00 7.00 14.00 21.00 28.00 35.00 42.00 49.00 56.00 63.00 70.00 77.00
Total Q Discharge(cfs)

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 4
Post-Development Bypass A
Hydrograph type = SCS Runoff Peak discharge = 1.679 cfs
Storm frequency = 1 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 4,741 cuft
Drainage area = 1.800 ac Curve number = 71*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 11.20 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(1.731 x 70)+(0.069 x 89)]/1.800
Post-Development Bypass A
Q (cfs) Hyd. No. 4 -- 1 Year Q (cfs)
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. 4 Time (min)

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TR55 Tc Worksheet
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. No. 4
Post-Development Bypass A
Description A B C Totals
Sheet Flow
Manning's n-value = 0.050 0.011 0.011
Flow length (ft) = 300.0 0.0 0.0
Two-year 24-hr precip. (in) = 3.49 0.00 0.00
Land slope (%) = 2.76 0.00 0.00
Travel Time (min) = 8.25 + 0.00 + 0.00 = 8.25
Shallow Concentrated Flow
Flow length (ft) = 423.60 0.00 0.00
Watercourse slope (%) = 2.20 0.00 0.00
Surface description = Unpaved Paved Paved
Average velocity (ft/s) =2.39 0.00 0.00
Travel Time (min) = 2.95 + 0.00 + 0.00 = 2.95
Channel Flow
X sectional flow area (sqft) = 0.00 0.00 0.00
Wetted perimeter(ft) = 0.00 0.00 0.00
Channel slope (%) = 0.00 0.00 0.00
Manning's n-value = 0.015 0.015 0.015
Velocity (ft/s) =0.00
0.00
0.00
Flow length (ft) ({0})0.0 0.0 0.0
Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00
Total Travel Time, Tc 11.20 min

12
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 5
Combined Post-Development
Hydrograph type = Combine Peak discharge = 1.715 cfs
Storm frequency = 1 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 37,165 cuft
Inflow hyds. = 3, 4 Contrib. drain. area = 1.800 ac
Combined Post-Development
Q (cfs) Hyd. No. 5-- 1 Year Q (cfs)
2.00 2.00
1.00 - 1.00
0.00 0.00
0 600 1200 1800 2400 3000 3600 4200 4800 5400 6000
Time (min)
Hyd No. 5 Hyd No. 3 Hyd No. 4

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 6
Pre-Development B
Hydrograph type = SCS Runoff Peak discharge = 2.585 cfs
Storm frequency = 1 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 6,777 cuft
Drainage area = 1.540 ac Curve number = 80*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 11.50 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(0.708 x 70)+(0.832 x 89)]/1.540
Pre-Development B
Q (cfs) Hyd. No. 6 -- 1 Year Q (cfs)
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. 6 Time (min)

14
TR55 Tc Worksheet
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. No. 6
Pre-Development B
Description A B C Totals
Sheet Flow
Manning's n-value = 0.050 0.011 0.011
Flow length (ft) = 300.0 0.0 0.0
Two-year 24-hr precip. (in) = 3.49 0.00 0.00
Land slope (%) = 2.14 0.00 0.00
Travel Time (min) = 9.13 + 0.00 + 0.00 = 9.13
Shallow Concentrated Flow
Flow length (ft) = 362.65 0.00 0.00
Watercourse slope (%) = 2.42 0.00 0.00
Surface description = Unpaved Paved Paved
Average velocity (ft/s) =2.51 0.00 0.00
Travel Time (min) = 2.41 + 0.00 + 0.00 = 2.41
Channel Flow
X sectional flow area (sqft) = 0.00 0.00 0.00
Wetted perimeter(ft) = 0.00 0.00 0.00
Channel slope (%) = 0.00 0.00 0.00
Manning's n-value = 0.015 0.015 0.015
Velocity (ft/s) =0.00
0.00
0.00
Flow length (ft) ({0})0.0 0.0 0.0
Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00
Total Travel Time, Tc 11.50 min

15
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 7
Post-Development B
Hydrograph type = SCS Runoff Peak discharge = 2.140 cfs
Storm frequency = 1 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 4,976 cuft
Drainage area = 1.530 ac Curve number = 75*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 9.00 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(0.440 x 89)+(1.090 x 70)]/1.530
Post-Development B
Q (cfs) Hyd. No. 7 -- 1 Year Q (cfs)
3.00 3.00
2.00 2.00
1.00 - 1.00
0.00 - J 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 7 Time (min)

16
TR55 Tc Worksheet
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. No. 7
Post-Development B
Description A B C Totals
Sheet Flow
Manning's n-value = 0.050 0.011 0.011
Flow length (ft) = 300.0 0.0 0.0
Two-year 24-hr precip. (in) = 3.49 0.00 0.00
Land slope (%) = 4.09 0.00 0.00
Travel Time (min) = 7.05 + 0.00 + 0.00 = 7.05
Shallow Concentrated Flow
Flow length (ft) = 228.22 0.00 0.00
Watercourse slope (%) = 1.51 0.00 0.00
Surface description = Unpaved Paved Paved
Average velocity (ft/s) =1.98 0.00 0.00
Travel Time (min) = 1.92 + 0.00 + 0.00 = 1.92
Channel Flow
X sectional flow area (sqft) = 0.00 0.00 0.00
Wetted perimeter(ft) = 0.00 0.00 0.00
Channel slope (%) = 0.00 0.00 0.00
Manning's n-value = 0.015 0.015 0.015
Velocity (ft/s) =0.00
0.00
0.00
Flow length (ft) ({0})0.0 0.0 0.0
Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00
Total Travel Time, Tc 9.00 min

17
Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph
No. type flow interval Peak volume hyd(s) elevation strge used Description
(origin) (cfs) (min) (min) (cuft) (ft) (cuft)
1 SCS Runoff 21.95 2 722 57,453 Pre-Development A
2 SCS Runoff 17.65 2 736 85,572 Post-Development A
3 Reservoir 13.87 2 750 83,410 2 458.41 29,044 Wet Pond Routing
4 SCS Runoff 5.488 2 722 14,363 Post-Development Bypass A
5 Combine 14.60 2 750 97,773 3,4 Combined Post-Development
6 SCS Runoff 6.462 2 720 16,778 Pre-Development B
7 SCS Runoff 5.985 2 718 13,693 Post-Development B
PrePost- Copy.gpw Return Period: 10 Year Thursday, 08/31 /2023

18
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 1
Pre-Development A
Hydrograph type = SCS Runoff Peak discharge = 21.95 cfs
Storm frequency = 10 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 57,453 cuft
Drainage area = 7.200 ac Curve number = 71*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 10.10 min
Total precip. = 5.02 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(6.903 x 70)+(0.297 x 89)]/7.200
Pre-Development A
Q (cfs) Hyd. No. 1 -- 10 Year Q (cfs)
24.00 24.00
20.00 20.00
16.00 16.00
12.00 12.00
8.00JL 8.00
4.00 4.00
0.00 - - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

19
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 2
Post-Development A
Hydrograph type = SCS Runoff Peak discharge = 17.65 cfs
Storm frequency = 10 yrs Time to peak = 736 min
Time interval = 2 min Hyd. volume = 85,572 cuft
Drainage area = 8.100 ac Curve number = 80*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 38.30 min
Total precip. = 5.02 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(4.470 x 89)+(3.630 x 70)]/8.100
Post-Development A
Q (cfs) Hyd. No. 2 -- 10 Year Q (cfs)
18.00 - - - - 18.00
15.00 15.00
12.00 12.00
9.00 9.00
6.00 6.00
iL—_
3.00 3.00
0.00 AM ` - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

20
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 3
Wet Pond Routing
Hydrograph type = Reservoir Peak discharge = 13.87 cfs
Storm frequency = 10 yrs Time to peak = 750 min
Time interval = 2 min Hyd. volume = 83,410 cuft
Inflow hyd. No. = 2 - Post-Development A Max. Elevation = 458.41 ft
Reservoir name = Wet Pond Max. Storage = 29,044 cuft
Storage Indication method used.
Wet Pond Routing
Q (cfs) Hyd. No. 3 -- 10 Year Q (cfs)
18.00 18.00
15.00 15.00
12.00 12.00
9.00 9.00
6.00 6.00
3.00 3.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 3 Hyd No. 2 111111111 Total storage used = 29,044 cuft

21
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 4
Post-Development Bypass A
Hydrograph type = SCS Runoff Peak discharge = 5.488 cfs
Storm frequency = 10 yrs Time to peak = 722 min
Time interval = 2 min Hyd. volume = 14,363 cuft
Drainage area = 1.800 ac Curve number = 71*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 11.20 min
Total precip. = 5.02 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(1.731 x 70)+(0.069 x 89)]/1.800
Post-Development Bypass A
Q (cfs) Hyd. No. 4 -- 10 Year Q (cfs)
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. 4 Time (min)

22
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 5
Combined Post-Development
Hydrograph type = Combine Peak discharge = 14.60 cfs
Storm frequency = 10 yrs Time to peak = 750 min
Time interval = 2 min Hyd. volume = 97,773 cuft
Inflow hyds. = 3, 4 Contrib. drain. area = 1.800 ac
Combined Post-Development
Q (cfs) Hyd. No. 5-- 10 Year Q (cfs)
15.00 15.00
12.00 — 12.00
9.00 9.00
6.00 6.00
3.00 3.00
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 Hyd No. 4

23
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 6
Pre-Development B
Hydrograph type = SCS Runoff Peak discharge = 6.462 cfs
Storm frequency = 10 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 16,778 cuft
Drainage area = 1.540 ac Curve number = 80*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 11.50 min
Total precip. = 5.02 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(0.708 x 70)+(0.832 x 89)]/1.540
Pre-Development B
Q (cfs) Hyd. No. 6 -- 10 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
JL
0.00 - - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 6 Time (min)

24
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 7
Post-Development B
Hydrograph type = SCS Runoff Peak discharge = 5.985 cfs
Storm frequency = 10 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 13,693 cuft
Drainage area = 1.530 ac Curve number = 75*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 9.00 min
Total precip. = 5.02 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(0.440 x 89)+(1.090 x 70)]/1.530
Post-Development B
Q (cfs) Hyd. No. 7 -- 10 Year Q(cfs)
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. 7 Time (min)

25
Hydrograph Summary Report Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. Hydrograph Peak Time Time to Hyd. Inflow Maximum Total Hydrograph
No. type flow interval Peak volume hyd(s) elevation strge used Description
(origin) (cfs) (min) (min) (cuft) (ft) (cuft)
1 SCS Runoff 41.52 2 720 107,658 Pre-Development A
2 SCS Runoff 30.18 2 736 146,739 Post-Development A
3 Reservoir 21.77 2 752 144,564 2 459.14 41,773 Wet Pond Routing
4 SCS Runoff 10.38 2 720 26,914 Post-Development Bypass A
5 Combine 22.97 2 752 171,478 3,4 Combined Post-Development
6 SCS Runoff 10.93 2 720 28,770 Pre-Development B
7 SCS Runoff 10.69 2 718 24,618 Post-Development B
PrePost- Copy.gpw Return Period: 100 Year Thursday, 08/31 /2023

26
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 1
Pre-Development A
Hydrograph type = SCS Runoff Peak discharge = 41.52 cfs
Storm frequency = 100 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 107,658 cuft
Drainage area = 7.200 ac Curve number = 71*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 10.10 min
Total precip. = 7.32 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(6.903 x 70)+(0.297 x 89)]/7.200
Pre-Development A
Q (cfs) Hyd. No. 1 -- 100 Year Q (cfs)
50.00 50.00
40.00J ..., 40.00
30.00 30.00
20.00 20.00
10.00 10.00
0.00 - ' l 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

27
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 2
Post-Development A
Hydrograph type = SCS Runoff Peak discharge = 30.18 cfs
Storm frequency = 100 yrs Time to peak = 736 min
Time interval = 2 min Hyd. volume = 146,739 cuft
Drainage area = 8.100 ac Curve number = 80*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 38.30 min
Total precip. = 7.32 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(4.470 x 89)+(3.630 x 70)]/8.100
Post-Development A
Q (cfs) Hyd. No. 2 -- 100 Year Q (cfs)
35.00 35.00
30.00 1 30.00
25.00 25.00
20.00 20.00
15.00 15.00
10.00 10.00
5.00 5.00
0.00 - -J LI I
- 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

28
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 3
Wet Pond Routing
Hydrograph type = Reservoir Peak discharge = 21.77 cfs
Storm frequency = 100 yrs Time to peak = 752 min
Time interval = 2 min Hyd. volume = 144,564 cuft
Inflow hyd. No. = 2 - Post-Development A Max. Elevation = 459.14 ft
Reservoir name = Wet Pond Max. Storage = 41,773 cuft
Storage Indication method used.
Wet Pond Routing
Q (cfs) Hyd. No. 3 -- 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
-JL.
0.00 - - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 3 Hyd No. 2 111111111 Total storage used = 41,773 cuft

29
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 4
Post-Development Bypass A
Hydrograph type = SCS Runoff Peak discharge = 10.38 cfs
Storm frequency = 100 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 26,914 cuft
Drainage area = 1.800 ac Curve number = 71*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 11.20 min
Total precip. = 7.32 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(1.731 x 70)+(0.069 x 89)]/1.800
Post-Development Bypass A
Q (cfs) Hyd. No. 4 -- 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
Hyd No. 4 Time (min)

30
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 5
Combined Post-Development
Hydrograph type = Combine Peak discharge = 22.97 cfs
Storm frequency = 100 yrs Time to peak = 752 min
Time interval = 2 min Hyd. volume = 171,478 cuft
Inflow hyds. = 3, 4 Contrib. drain. area = 1.800 ac
Combined Post-Development
Q (cfs) Hyd. No. 5 -- 100 Year Q (cfs)
24.00 24.00
kl
20.00 20.00
16.00 16.00
12.00 12.00
8.00 8.00
4.00 4.00
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 Hyd No. 4

31
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 6
Pre-Development B
Hydrograph type = SCS Runoff Peak discharge = 10.93 cfs
Storm frequency = 100 yrs Time to peak = 720 min
Time interval = 2 min Hyd. volume = 28,770 cuft
Drainage area = 1.540 ac Curve number = 80*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 11.50 min
Total precip. = 7.32 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(0.708 x 70)+(0.832 x 89)]/1.540
Pre-Development B
Q (cfs) Hyd. No. 6 -- 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
Hyd No. 6 Time (min)

32
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Hyd. No. 7
Post-Development B
Hydrograph type = SCS Runoff Peak discharge = 10.69 cfs
Storm frequency = 100 yrs Time to peak = 718 min
Time interval = 2 min Hyd. volume = 24,618 cuft
Drainage area = 1.530 ac Curve number = 75*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 9.00 min
Total precip. = 7.32 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(0.440 x 89)+(1.090 x 70)]/1.530
Post-Development B
Q (cfs) Hyd. No. 7 -- 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
Hyd No. 7 Time (min)

33
Hydraflow Rainfall Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Thursday,08/31 /2023
Return Intensity-Duration-Frequency Equation Coefficients(FHA)
Period
(Yrs) B D E (N/A)
1 63.1989 12.9000 0.8933
2 68.6781 12.6000 0.8716
3 0.0000 0.0000 0.0000
5 76.7442 13.3000 0.8516
10 71.4662 12.4000 0.8035
25 62.7327 11.1000 0.7421
50 55.2033 9.9000 0.6905
100 51.6854 9.2000 0.6559
File name: NCNG CB BOM Yard.IDF
Intensity= B/(Tc+ D)AE
Return Intensity Values(in/hr)
Period
(Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60
1 4.80 3.85 3.23 2.79 2.46 2.20 1.99 1.82 1.68 1.56 1.46 1.37
2 5.64 4.54 3.81 3.30 2.91 2.61 2.37 2.17 2.01 1.87 1.75 1.64
3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
5 6.46 5.25 4.45 3.88 3.44 3.10 2.82 2.60 2.41 2.24 2.10 1.98
10 7.20 5.88 5.00 4.37 3.89 3.52 3.22 2.97 2.76 2.58 2.43 2.29
25 7.98 6.53 5.57 4.89 4.38 3.98 3.65 3.39 3.16 2.97 2.80 2.65
50 8.55 7.00 6.00 5.28 4.75 4.33 3.99 3.71 3.47 3.27 3.09 2.94
100 9.07 7.44 6.39 5.65 5.10 4.66 4.31 4.01 3.77 3.56 3.37 3.21
Tc=time in minutes.Values may exceed 60.
Precip.file name:R:\333\39004-NCNG MORGANTON RRC\Calcs\Stormwater\Morganton.pcp
Rainfall Precipitation Table (in)
Storm
Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr
SCS 24-hour 2.90 3.49 0.00 4.43 5.02 6.79 7.70 7.32
SCS 6-Hr 2.08 2.50 0.00 3.11 3.60 4.35 4.98 5.46
Huff-1st 0.00 0.00 0.00 2.75 0.00 0.00 0.00 0.00
Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-Indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Custom 0.00 0.00 0.00 2.80 0.00 0.00 0.00 0.00