SW5240601_Design Calculations_20240617

1
Watershed Model Schematic Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
r �4-Pre-Dev to Analysis Point'B'
C2Pe-Dev to Analysis Point'A'
�
o t1Pst-Dev'A'Pond
�5 Po
st-Dev Pst-Dev to Analysis Point'B'
�
V
1.13-Pond'A'
Legend
Hyd. Origin Description
1 SCS Runoff Post-Dev'A'Pond
2 SCS Runoff Pre-Dev to Analysis Point'A'
3 Reservoir Pond'A'
4 SCS Runoff Pre-Dev to Analysis Point'B'
5 SCS Runoff Post-Dev to Analysis Point'B'
Project: SBI HQ.gpw Wednesday, 05/8/2024

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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 13.16 18.21 26.18 32.74 41.70 56.42 Post-Dev'A'Pond
2 SCS Runoff 5.005 7.728 12.22 16.06 21.45 30.57 Pre-Dev to Analysis Point'A'
3 Reservoir 1 1.699 5.311 12.13 21.75 33.29 41.20 Pond'A'
4 SCS Runoff 2.050 3.153 4.970 6.520 8.701 12.41 Pre-Dev to Analysis Point'B'
5 SCS Runoff 1.575 2.387 3.718 4.847 6.425 9.100 Post-Dev to Analysis Point'B'
Proj. file: SBI HQ.gpw Wednesday, 05/8/2024

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 13.16 2 734 57,751 Post-Dev'A'Pond
2 SCS Runoff 5.005 2 742 29,898 i Pre-Dev to Analysis Point'A'
3 Reservoir 1.699 2 796 55,480 1 331.25 31,381 Pond'A'
4 SCS Runoff 2.050 2 736 10,255 Pre-Dev to Analysis Point'B'
5 SCS Runoff 1.575 2 738 8,326 Post-Dev to Analysis Point'B'
SBI HQ.gpw Return Period: 1 Year Wednesday, 05/8/2024

4
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 1
Post-Dev 'A' Pond
Hydrograph type = SCS Runoff Peak discharge = 13.16 cfs
Storm frequency = 1 yrs Time to peak = 734 min
Time interval = 2 min Hyd. volume = 57,751 cuft
Drainage area = 12.080 ac Curve number = 82*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 30.80 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(6.550 x 98)+(0.700 x 85)+(4.830 x 61)]/12.080
Post-Dev 'A' Pond
Q (cfs) Hyd. No. 1 -- 1 Year Q (cfs)
14.00 14.00
12.00 12.00
10.00 10.00
8.00 8.00
6.00 6.00
4.00 I 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)

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TR55 Tc Worksheet
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. No. 1
Post-Dev 'A' Pond
Description A B C Totals
Sheet Flow
Manning's n-value = 0.410 0.011 0.011
Flow length (ft) = 176.0 0.0 0.0
Two-year 24-hr precip. (in) = 2.25 3.50 0.00
Land slope (%) = 5.00 0.00 0.00
Travel Time (min) = 28.46 + 0.00 + 0.00 = 28.46
Shallow Concentrated Flow
Flow length (ft) = 160.00 0.00 0.00
Watercourse slope (%) = 1.25 0.00 0.00
Surface description = Unpaved Paved Paved
Average velocity (ft/s) =1.80 0.00 0.00
Travel Time (min) = 1.48 + 0.00 + 0.00 = 1.48
Channel Flow
X sectional flow area (sqft) = 1.77 3.14 0.00
Wetted perimeter(ft) = 4.71 6.28 0.00
Channel slope (%) = 2.40 2.40 0.00
Manning's n-value = 0.013 0.013 0.015
Velocity (ft/s) =9.22
11.16
0.00
Flow length (ft) ({0})400.0 115.0 0.0
Travel Time (min) = 0.72 + 0.17 + 0.00 = 0.90
Total Travel Time, Tc 30.80 min

6
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 2
Pre-Dev to Analysis Point 'A'
Hydrograph type = SCS Runoff Peak discharge = 5.005 cfs
Storm frequency = 1 yrs Time to peak = 742 min
Time interval = 2 min Hyd. volume = 29,898 cuft
Drainage area = 9.830 ac Curve number = 74*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 45.80 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(2.130 x 98)+(0.190 x 85)+(2.050 x 61)+(5.460 x 69)]/9.830
Pre-Dev to Analysis Point 'A'
Q (cfs) Hyd. No. 2 -- 1 Year Q (cfs)
6.00 6.00
5.00 1 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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TR55 Tc Worksheet
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. No. 2
Pre-Dev to Analysis Point 'A'
Description A B C Totals
Sheet Flow
Manning's n-value = 0.410 0.011 0.011
Flow length (ft) = 300.0 0.0 0.0
Two-year 24-hr precip. (in) = 3.50 0.00 0.00
Land slope (%) = 3.03 0.00 0.00
Travel Time (min) = 42.71 + 0.00 + 0.00 = 42.71
Shallow Concentrated Flow
Flow length (ft) = 14.18 220.00 55.13
Watercourse slope (%) = 4.94 1.36 2.50
Surface description = Unpaved Paved Unpaved
Average velocity (ft/s) =3.59 2.37 2.55
Travel Time (min) = 0.07 + 1.55 + 0.36 = 1.97
Channel Flow
X sectional flow area (sqft) = 4.91 5.00 0.00
Wetted perimeter(ft) = 7.85 10.20 0.00
Channel slope (%) = 1.15 2.55 0.00
Manning's n-value = 0.015 0.026 0.015
Velocity (ft/s) =7.78
5.68
0.00
Flow length (ft) ({0})196.6 237.3 0.0
Travel Time (min) = 0.42 + 0.70 + 0.00 = 1.12
Total Travel Time, Tc 45.80 min

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 3
Pond 'A'
Hydrograph type = Reservoir Peak discharge = 1.699 cfs
Storm frequency = 1 yrs Time to peak = 796 min
Time interval = 2 min Hyd. volume = 55,480 cuft
Inflow hyd. No. = 1 - Post-Dev 'A' Pond Max. Elevation = 331.25 ft
Reservoir name = Pond 'A' Max. Storage = 31,381 cuft
Storage Indication method used.
Pond 'A'
Q (cfs) Hyd. No. 3 -- 1 Year Q (cfs)
14.00 14.00
12.00 12.00
10.00 10.00
8.00 8.00
6.00 6.00
4.00 4.00
2.00 i 2.00
0.00 - 0.00
0 600 1200 1800 2400 3000 3600 4200 4800 5400 6000
Time (min)
Hyd No. 3 Hyd No. 1 111111111 Total storage used = 31,381 cuft

Pond Report 9
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Pond No. 1 - Pond 'A'
Pond Data
Contours-User-defined contour areas.Conic method used for volume calculation.Begining Elevation=329.50 ft
Stage/Storage Table
Stage(ft) Elevation(ft) Contour area(sqft) Incr.Storage(cuft) Total storage(cuft)
0.00 329.50 15,805 0 0
0.50 330.00 17,358 8,287 8,287
1.50 331.00 18,967 18,155 26,442
2.50 332.00 20,632 19,792 46,233
3.50 333.00 22,354 21,485 67,718
4.50 334.00 24,132 23,235 90,953
Culvert/Orifice Structures Weir Structures
[A] [B] [C] [PrfRsr] [A] [B] [C] [D]
Rise(in) = 24.00 2.25 8.00 0.00 Crest Len(ft) = 16.00 Inactive 10.00 0.00
Span(in) = 24.00 2.25 36.00 0.00 Crest El.(ft) = 332.00 330.97 333.00 0.00
No.Barrels = 1 1 1 0 Weir Coeff. = 3.33 3.33 3.33 3.33
Invert El.(ft) = 325.50 329.50 330.97 0.00 Weir Type = 1 Rect Broad ---
Length(ft) = 42.00 0.67 0.67 0.00 Multi-Stage = Yes No No No
Slope(%) = 1.20 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)
5.00 334.50
I
4.00 333.50
3.00 - 332.50
2.00 331.50
1.00 330.50
0.00 329.50
0.00 8.00 16.00 24.00 32.00 40.00 48.00 56.00 64.00 72.00 80.00
Total Q Discharge(cfs)

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Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 4
Pre-Dev to Analysis Point 'B'
Hydrograph type = SCS Runoff Peak discharge = 2.050 cfs
Storm frequency = 1 yrs Time to peak = 736 min
Time interval = 2 min Hyd. volume = 10,255 cuft
Drainage area = 3.380 ac Curve number = 74*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 35.50 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(1.160 x 98)+(2.220 x 61)]/3.380
Pre-Dev to Analysis Point 'B'
Q (cfs) Hyd. No. 4 -- 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. 4 Time (min)

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TR55 Tc Worksheet
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. No. 4
Pre-Dev to Analysis Point 'B'
Description A B C Totals
Sheet Flow
Manning's n-value = 0.410 0.011 0.011
Flow length (ft) = 300.0 0.0 0.0
Two-year 24-hr precip. (in) = 3.50 0.00 0.00
Land slope (%) = 4.83 0.00 0.00
Travel Time (min) = 35.44 + 0.00 + 0.00 = 35.44
Shallow Concentrated Flow
Flow length (ft) = 4.32 0.00 0.00
Watercourse slope (%) = 4.17 0.00 0.00
Surface description = Unpaved Paved Paved
Average velocity (ft/s) =3.29 0.00 0.00
Travel Time (min) = 0.02 + 0.00 + 0.00 = 0.02
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 35.50 min

12
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 5
Post-Dev to Analysis Point 'B'
Hydrograph type = SCS Runoff Peak discharge = 1.575 cfs
Storm frequency = 1 yrs Time to peak = 738 min
Time interval = 2 min Hyd. volume = 8,326 cuft
Drainage area = 2.560 ac Curve number = 75*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 39.50 min
Total precip. = 2.90 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(0.980 x 98)+(1.580 x 61)]/2.560
Post-Dev to Analysis Point 'B'
Q (cfs) Hyd. No. 5-- 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. 5 Time (min)

13
TR55 Tc Worksheet
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023
Hyd. No. 5
Post-Dev to Analysis Point 'B'
Description A B C Totals
Sheet Flow
Manning's n-value = 0.410 0.011 0.011
Flow length (ft) = 299.9 0.0 0.0
Two-year 24-hr precip. (in) = 3.50 0.00 0.00
Land slope (%) = 3.88 0.00 0.00
Travel Time (min) = 38.68 + 0.00 + 0.00 = 38.68
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) = 0.55 0.00 0.00
Wetted perimeter(ft) = 2.62 0.00 0.00
Channel slope (%) = 3.30 0.00 0.00
Manning's n-value = 0.015 0.015 0.015
Velocity (ft/s) =6.31
0.00
0.00
Flow length (ft) ({0})310.8 0.0 0.0
Travel Time (min) = 0.82 + 0.00 + 0.00 = 0.82
Total Travel Time, Tc 39.50 min

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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 32.74 2 732 141,481 Post-Dev'A'Pond
2 SCS Runoff 16.06 2 742 87,008 Pre-Dev to Analysis Point'A'
3 Reservoir 21.75 2 748 139,122 1 332.36 53,985 Pond'A'
4 SCS Runoff 6.520 2 736 29,844 Pre-Dev to Analysis Point'B'
5 SCS Runoff 4.847 2 738 23,668 Post-Dev to Analysis Point'B'
SBI HQ.gpw Return Period: 10 Year Wednesday, 05/8/2024

15
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 1
Post-Dev 'A' Pond
Hydrograph type = SCS Runoff Peak discharge = 32.74 cfs
Storm frequency = 10 yrs Time to peak = 732 min
Time interval = 2 min Hyd. volume = 141,481 cuft
Drainage area = 12.080 ac Curve number = 82*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 30.80 min
Total precip. = 5.12 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(6.550 x 98)+(0.700 x 85)+(4.830 x 61)]/12.080
Post-Dev 'A' Pond
Q (cfs) Hyd. No. 1 -- 10 Year Q (cfs)
35.00 - 35.00
I
30.00 30.00
25.00 25.00
20.00 20.00
15.00 15.00
10.00 10.00
5.00 5.00
II
0.00 - 7 - 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 1 Time (min)

16
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 2
Pre-Dev to Analysis Point 'A'
Hydrograph type = SCS Runoff Peak discharge = 16.06 cfs
Storm frequency = 10 yrs Time to peak = 742 min
Time interval = 2 min Hyd. volume = 87,008 cuft
Drainage area = 9.830 ac Curve number = 74*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 45.80 min
Total precip. = 5.12 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(2.130 x 98)+(0.190 x 85)+(2.050 x 61)+(5.460 x 69)]/9.830
Pre-Dev to Analysis Point 'A'
Q (cfs) Hyd. No. 2 -- 10 Year Q (cfs)
18.00 - - - 18.00
1
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
Hyd No. 2 Time (min)

17
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 3
Pond 'A'
Hydrograph type = Reservoir Peak discharge = 21.75 cfs
Storm frequency = 10 yrs Time to peak = 748 min
Time interval = 2 min Hyd. volume = 139,122 cuft
Inflow hyd. No. = 1 - Post-Dev 'A' Pond Max. Elevation = 332.36 ft
Reservoir name = Pond 'A' Max. Storage = 53,985 cuft
Storage Indication method used.
Pond 'A'
Q (cfs) Hyd. No. 3 -- 10 Year Q (cfs)
35.00 35.00
30.00 30.00
25.00 25.00
20.00 20.00
1
1
I _
15.00 I 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. 3 Hyd No. 1 111111111 Total storage used = 53,985 cuft

18
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 4
Pre-Dev to Analysis Point 'B'
Hydrograph type = SCS Runoff Peak discharge = 6.520 cfs
Storm frequency = 10 yrs Time to peak = 736 min
Time interval = 2 min Hyd. volume = 29,844 cuft
Drainage area = 3.380 ac Curve number = 74*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 35.50 min
Total precip. = 5.12 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(1.160 x 98)+(2.220 x 61)]/3.380
Pre-Dev to Analysis Point 'B'
Q (cfs) Hyd. No. 4 -- 10 Year Q (cfs)
7.00 7.00
6.00 6.00
5.00 — 5.00
4.00 4.00
3.00 3.00
I
2.00 2.00
1.00 1.00
J
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 4 Time (min)

19
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 5
Post-Dev to Analysis Point 'B'
Hydrograph type = SCS Runoff Peak discharge = 4.847 cfs
Storm frequency = 10 yrs Time to peak = 738 min
Time interval = 2 min Hyd. volume = 23,668 cuft
Drainage area = 2.560 ac Curve number = 75*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 39.50 min
Total precip. = 5.12 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(0.980 x 98)+(1.580 x 61)]/2.560
Post-Dev to Analysis Point 'B'
Q (cfs) Hyd. No. 5-- 10 Year Q (cfs)
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. 5 Time (min)

20
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 56.42 2 732 246,281 Post-Dev'A'Pond
2 SCS Runoff 30.57 2 740 163,794 Pre-Dev to Analysis Point'A'
3 Reservoir 41.20 2 746 243,880 1 333.18 71,841 Pond'A'
4 SCS Runoff 12.41 2 734 56,182 Pre-Dev to Analysis Point'B'
5 SCS Runoff 9.100 2 736 44,094 Post-Dev to Analysis Point'B'
SBI HQ.gpw Return Period: 100 Year Wednesday, 05/8/2024

21
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 1
Post-Dev 'A' Pond
Hydrograph type = SCS Runoff Peak discharge = 56.42 cfs
Storm frequency = 100 yrs Time to peak = 732 min
Time interval = 2 min Hyd. volume = 246,281 cuft
Drainage area = 12.080 ac Curve number = 82*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 30.80 min
Total precip. = 7.67 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(6.550 x 98)+(0.700 x 85)+(4.830 x 61)]/12.080
Post-Dev 'A' Pond
Q (cfs) Hyd. No. 1 -- 100 Year Q (cfs)
60.00 60.00
1
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. 1 Time (min)

22
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 2
Pre-Dev to Analysis Point 'A'
Hydrograph type = SCS Runoff Peak discharge = 30.57 cfs
Storm frequency = 100 yrs Time to peak = 740 min
Time interval = 2 min Hyd. volume = 163,794 cuft
Drainage area = 9.830 ac Curve number = 74*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 45.80 min
Total precip. = 7.67 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(2.130 x 98)+(0.190 x 85)+(2.050 x 61)+(5.460 x 69)]/9.830
Pre-Dev to Analysis Point 'A'
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
0.00 — 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Hyd No. 2 Time (min)

23
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 3
Pond 'A'
Hydrograph type = Reservoir Peak discharge = 41.20 cfs
Storm frequency = 100 yrs Time to peak = 746 min
Time interval = 2 min Hyd. volume = 243,880 cuft
Inflow hyd. No. = 1 - Post-Dev 'A' Pond Max. Elevation = 333.18 ft
Reservoir name = Pond 'A' Max. Storage = 71,841 cuft
Storage Indication method used.
Pond 'A'
Q (cfs) Hyd. No. 3 -- 100 Year Q (cfs)
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. 3 Hyd No. 1 111111111 Total storage used = 71,841 cuft

24
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 4
Pre-Dev to Analysis Point 'B'
Hydrograph type = SCS Runoff Peak discharge = 12.41 cfs
Storm frequency = 100 yrs Time to peak = 734 min
Time interval = 2 min Hyd. volume = 56,182 cuft
Drainage area = 3.380 ac Curve number = 74*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 35.50 min
Total precip. = 7.67 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(1.160 x 98)+(2.220 x 61)]/3.380
Pre-Dev to Analysis Point 'B'
Q (cfs) Hyd. No. 4 -- 100 Year Q (cfs)
14.00 14.00
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)

25
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Hyd. No. 5
Post-Dev to Analysis Point 'B'
Hydrograph type = SCS Runoff Peak discharge = 9.100 cfs
Storm frequency = 100 yrs Time to peak = 736 min
Time interval = 2 min Hyd. volume = 44,094 cuft
Drainage area = 2.560 ac Curve number = 75*
Basin Slope = 0.0 % Hydraulic length = 0 ft
Tc method = TR55 Time of conc. (Tc) = 39.50 min
Total precip. = 7.67 in Distribution = Type II
Storm duration = 24 hrs Shape factor = 484
*Composite(Area/CN)=[(0.980 x 98)+(1.580 x 61)]/2.560
Post-Dev to Analysis Point 'B'
Q (cfs) Hyd. No. 5 -- 100 Year Q (cfs)
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. 5 Time (min)

26
Hydraflow Rainfall Report
Hydraflow Hydrographs Extension for Autodesk®Civil 3D®by Autodesk, Inc.v2023 Wednesday,05/8/2024
Return Intensity-Duration-Frequency Equation Coefficients(FHA)
Period
(Yrs) B D E (N/A)
1 67.6239 13.2000 0.9048
2 74.1911 13.1000 0.8854
3 0.0000 0.0000 0.0000
5 72.3793 12.7000 0.8349
10 72.4736 12.4000 0.8027
25 52.8649 9.5000 0.7022
50 58.8641 10.3000 0.7023
100 50.6951 8.9000 0.6490
File name:SBI HQ.IDF
Intensity= B/(Tc+ D)^E
Return Intensity Values(in/hr)
Period
(Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60
1 4.90 3.93 3.30 2.84 2.50 2.24 2.03 1.86 1.71 1.59 1.48 1.39
2 5.71 4.60 3.87 3.35 2.96 2.65 2.40 2.20 2.03 1.89 1.77 1.66
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 6.57 5.34 4.52 3.94 3.50 3.15 2.87 2.64 2.45 2.29 2.14 2.02
10 7.32 5.97 5.08 4.44 3.96 3.58 3.27 3.02 2.81 2.63 2.47 2.33
25 8.08 6.57 5.59 4.91 4.40 4.00 3.68 3.41 3.19 3.00 2.83 2.69
50 8.67 7.11 6.09 5.36 4.82 4.39 4.04 3.76 3.52 3.31 3.13 2.97
100 9.19 7.52 6.46 5.71 5.15 4.71 4.35 4.06 3.81 3.60 3.41 3.25
Tc=time in minutes.Values may exceed 60.
Precip.file name:Sample.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 3.50 0.00 4.40 5.12 6.09 6.87 7.67
SCS 6-Hr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Huff-1st 0.00 0.00 0.00 0.00 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 0.00 0.00 0.00 0.00 0.00

WET POND SIZING DATE
4/29/2024 •••.
PROJECT NAME PROJECT NO
SBI HQ Addition&Renovation 57879 TIMMONS GROUP
LOCATION BY
Raleigh, NC Jake Lewis
POND A
Drainage Area,(DA)= 12.08 ac
Impervious Area c=0.95 7.25 ac
Pervious Area c= 0.30 4.83 ac Q1 Pre= 5.0 cfs
CN= 83 Q1Post= 2.4 cfs
Permanent Water Quality Pool
% Impervious= 60.0
Permanent Pool Design Depth= 3.00 ft
SA/DA Ratio= 2.09 (from Tbl. 1.1)
Required Surface Area= 11,001 sf
Permanent Pool Volume Req.= 33,004 cf
Temporary Water Quality Pool
Design Storm Rainfall 1.00 in (Typically 1-in)
Runoff Coeff.(Rv=0.05+0.009(%Imperv.))= 0.59 in/in
Required Volume(design rainfall)(Rv)(DA)= 25,878.27 cf
Surface Area Provided:
Permanent Pool Max.Depth= 4.00 ft
Area of Pond Bottom(Above PSS)= 8,859 sf
Area Bottom of Shelf= 11,655 sf
Area of Permanent Pool= 13,149 sf
Area Top of Shelf= 14,708 sf
Perm.Pool Volume Provided= 39,966 cf > 33,004 OK
Avg.Perm.Pool Depth Provided(Eq.3). 3.04 ft > 3.00 OK
Surface Area at 1"Storage Volume= 18,917 sf (EL=330.97)
1"Storage Volume Provided= 25,884 cf > 25,878 OK
Temp.Storage Depth above Dewatering Hole= 1.47 ft
Diameter of Dewatering Hole= 2.25 in
Detention(Draw-Down)Time = 3.3 days (2-5 days Required)
T days=(Temp.Storage Vol Req/(0.6"A*(2*g*(h))^1/2)*86400
(where h=one third temp.storage depth measured to centroid of orifice)
Max Drawdow Rate= 0.16 cfs
Permanent Pool Volume= 39,966 cf > 33,004 OK
Forebay Volume Required= 5,995 cf
Forebay Volume Provided= 6,104 cf
15.3 % OK
Table 1.1
SA/DA Ratios 85%TSS efficiency
Permanent Pool Depth(ft)
%Impervious 3.0 4.0 5.0 6.0
10 0.51 0.43 0.37 0.30
20 0.84 0.69 0.61 0.51
30 1.17 0.94 0.84 0.72
40 1.51 1.24 1.09 0.91
50 1.79 1.51 1.31 1.13
60 2.09 1.77 1.49 1.31
70 2.51 2.09 1.80 1.56
80 2.92 2.41 2.07 1.82
90 3.25 2.64 2.31 2.04
s:\1319\0001\calcs\PondSize-Wet Pond-piedmont-90 tss printed:5/8/2024 12:18 PM Page 1 of 3

DATE
POND A
Main Pool Permanent Pool Volume
Stage(ft) Elevation Area(sf) Storage(cf)
-4.00 325.50 8,418 Top of Sed.Stor.in Main Pond
-3.00 326.50 8,859 8,638
-2.00 327.50 9,762 17,949
-1.00 328.50 10,694 28,177
-0.50 329.00 11,655 33,765 Inside of Shelf Elev.
0.00 329.50 13,149 39,966 Normal Pool Elev.
0.50 330.00 14,708 46,930 Outside of Shelf Elev.
Forebay Volume
Stage(ft) Elevation Area(sf) Storage(cf)
Top of Sed.Stor.in Forebay
-4.00 325.50 845 0
-3.00 326.50 1,183 1,014
-2.00 327.50 1,460 2,335
-1.00 328.50 1,766 3,948
-0.50 329.00 2,100 4,915
0.00 329.50 2,656 6,104 Normal Pool Elev.
Total Pond Stage/Storage Detail
0.00 329.5 15,805 0 Normal Pool Elev.
0.50 330 17,358 8290.72
25883.68134 Water Quality Elevation
1.50 331 18,967 26452.775
2.50 332 20631.93 46251.99
3.50 333 22353.92 67744.915
4.50 334 24132.45 90988.1
Anti-Floatation
Invert of Riser: 325.50 ft
Crest of Riser: 332.00 ft
Inside Width of Riser 4.00 ft
Inside Length of Riser: 4.00 ft
Riser Wall Thickness: 8.00 in
Volume of Riser: 184.89 cf
Volume of Riser Walls: 80.89 cf
Weight of Concrete: 150 lbs/cf
Buoyancy Force: 62.4 lbs/cf
Weight of Riser Walls: 12,133 lbs
Buoyancy Force of Riser: 11,537 lbs
Weight of Riser minus Buoyancy Force 596 lbs
Width of Anchor extension 0 in
Thickness of Anchor extension 20 in
Weight of Water acting on anchor extension 0 lbs
Weight of extension required(concrete) None lbs
Safety Factor(SF) 1.3
Weight of extension required with SF 0 lbs
Anchor Length: 5.33 ft
Anchor Width: 5.33 ft
Volume of Anchor: 47 cf
Weight of Proposed Anchor 7111 lbs
Is Anchor sufficient? YES
Total Downward Force: 19,244 lbs
Total Boyancy Force: 11,537 lbs
Total Safety Factor: 1.7
s:\1319\0001\calcs\PondSize-Wet Pond-piedmont-90 tss printed:5/8/2024 12:18 PM Page 2 of 3

OUTLET PROTECTION DATE
DESIGN 5/9/2024 ••••.e
PROJECT NAME PROJECT NO TIMMONS GROUP
SBI Head.uarters Addition&Renovation 57879 YOUR VISION ACHIEVED THROUGH OURS.
LOCATION BY
Raleigh, NC TM
Rip Rap Energy Dissipator RR-1
Pipe Diameter: 30.00 in
Upper Invert: 325.50
Lower Invert: 325.03
Pipe Length: 40.06 ft *Discharge from Storm Sewers
Pipe Slope: 0.012 Discharge: 32.74 cfs
Pipe Material: RCP
Q25= 32.74 cfs Q25/Qfull = 0.74
Qfull= 44.50 cfs V/Vfull= 1.09
Vfull= 9.06 fps V= 9.88 fps
Dissipator Dimensions* Zone= 2
Stone Filling Class= B
Entry Width(3 X Do)= 7.5 ft 15.0 ft
Length(6 X Do)= 15.0 ft 15.0 ft
Width(La+Do)= 17.5 ft 15.0 ft
Min.Thickness= 24 inches
Stone Diameter(Dso)= 6 inches
1- 15.0
7.5 17.5
*All units are in feet
**Dissipator pad designed for full flow of pipe
57879 Rip Rap Calcs 5/9/2024 Page 1 of 1