SW6230104_Design Calculations_20230126

Watershed Model Schematic Hydraflow Hydrographs Extension forAutodesk® Civil 3D® by Autodesk, Inc. v2020
1
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Petco - Dunn, NC Storm Water Calculations
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10.27.2022
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Project: Dunn NC drainageBA.gpw
Thursday, 10 / 27 / 2022

Hydrograph Summary Report HydraflowHydrographsExtension for AutodeskOCivil 3DObyAutodesk,Inc. v202O
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1
SCS Runoff
2.054
2
722
5,576
------
------
------
existing
2
SCS Runoff
5.400
2
716
11,101
------
------
------
proposed
3
Reservoir
1.478
2
724
8,010
2
171.70
5,479
Pond routing
Dunn NC drainageBA.gpw
Return Period: 1 Year
Thursday, 10 / 27 / 2022

3
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020
Thursday, 10 / 27 / 2022
Hyd. No. 3
Pond routing
Hydrograph type
= Reservoir
Peak discharge
= 1.478 cfs
Storm frequency
= 1 yrs
Time to peak
= 724 min
Time interval
= 2 min
Hyd. volume
= 8,010 cuft
Inflow hyd. No.
= 2 -proposed
Max. Elevation
= 171.70 ft
Reservoir name
= <New Pond>
Max. Storage
= 5,479 cuft
Storage Indication method used.
Q (cfs)
6.00
5.00
4.00
3.00
r M
1.00
Pond routing
Hyd. No. 3 -- 1 Year
Q (cfs)
6.00
5.00
4.00
3.00
2.00
1.00
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 Total storage used = 5,479 cult

Pond Report 4
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020
Thursday, 10 / 27 / 2022
Pond No. 1 - <New Pond>
Pond Data
Contours -User-defined contour areas.
Average end area method
used for volume calculation. Begining Elevation = 169.50 ft
Stage / Storage Table
Stage (ft) Elevation (ft)
Contour area (sqft)
Incr. Storage (cuft)
Total storage (cuft)
0.00 169.50
1,366
0
0
0.50 170.00
1,815
795
795
1.50 171.00
2,766
2,291
3,086
2.50 172.00
4,064
3,415
6,501
3.50 173.00
14,666
9,365
15,866
Culvert / Orifice Structures
Weir Structures
[A]
[B]
[C]
[PrfRsr]
[A]
[B]
[C]
[D]
Rise (in)
= 6.00
0.00
0.00
0.00
Crest Len (ft)
= 20.00
0.00
0.00
0.00
Span (in)
= 12.00
0.00
0.00
0.00
Crest El. (ft)
= 172.00
0.00
0.00
0.00
No. Barrels
= 1
0
0
0
Weir Coeff.
= 3.33
3.33
3.33
3.33
Invert El. (ft)
= 171.00
0.00
0.00
0.00
Weir Type
= Rect
---
---
---
Length (ft)
= 1.00
0.00
0.00
0.00
Multi -Stage
= No
No
No
No
Slope (%)
= 1.00
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
No
No
No
TW Elev. (ft)
= 0.00
Stage (ft)
4.00
Ulm
RIM
M
0.00 ' '
0.00 7.00
Total Q
Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s).
Stage / Discharge
14.00 21.00 28.00 35.00 42.00 49.00 56.00
Elev (ft)
173.50
172.50
171.50
170.50
169.50
63.00 70.00
Discharge (cfs)

Hydrograph Summary Report HydraflowHydrographsExtension for AutodeskOCivil 3DObyAutodesk,Inc. v202O
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1
SCS Runoff
6.655
2
720
17,275
------
------
------
existing
2
SCS Runoff
11.54
2
716
24,763
------
------
------
proposed
3
Reservoir
9.509
2
720
21,672
2
172.22
8,595
Pond routing
Dunn NC drainageBA.gpw
Return Period: 10 Year
Thursday, 10 / 27 / 2022

A
Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020
Thursday, 10 / 27 / 2022
Hyd. No. 3
Pond routing
Hydrograph type
= Reservoir
Peak discharge
= 9.509 cfs
Storm frequency
= 10 yrs
Time to peak
= 720 min
Time interval
= 2 min
Hyd. volume
= 21,672 cuft
Inflow hyd. No.
= 2 -proposed
Max. Elevation
= 172.22 ft
Reservoir name
= <New Pond>
Max. Storage
= 8,595 cuft
Storage Indication method used.
Q (cfs)
12.00
10.00
M
M
4.00
r M�
Pond routing
Hyd. No. 3 -- 10 Year
Q (cfs)
12.00
10.00
M
. ��
4.00
r M�
0.00
120 240 360 480 600 720 840 960 1080 1200 1320 1440 1560
Time (min)
Hyd No. 3 Hyd No. 2 Total storage used = 8,595 cult

Hydrograph Summary Report HydraflowHydrographsExtension for AutodeskOCivil 3DObyAutodesk,Inc. v202O
Hyd.
No.
Hydrograph
type
(origin)
Peak
flow
(cfs)
Time
interval
(min)
Time to
Peak
(min)
Hyd.
volume
(cuft)
Inflow
hyd(s)
Maximum
elevation
(ft)
Total
strge used
(cuft)
Hydrograph
Description
1
SCS Runoff
13.27
2
720
34,628
------
------
------
existing
2
SCS Runoff
19.16
2
716
42,592
------
------
------
proposed
3
Reservoir
17.36
2
718
39,501
2
172.37
9,925
Pond routing
Dunn NC drainageBA.gpw
Return Period: 100 Year
Thursday, 10 / 27 / 2022

Hydrograph Report
Hydraflow Hydrographs Extension for Autodesk® Civil 3D® by Autodesk, Inc. v2020
Thursday, 10 / 27 / 2022
Hyd. No. 3
Pond routing
Hydrograph type
= Reservoir
Peak discharge
= 17.36 cfs
Storm frequency
= 100 yrs
Time to peak
= 718 min
Time interval
= 2 min
Hyd. volume
= 39,501 cuft
Inflow hyd. No.
= 2 -proposed
Max. Elevation
= 172.37 ft
Reservoir name
= <New Pond>
Max. Storage
= 9,925 cuft
Storage Indication method used.
Q (cfs)
21.00
18.00
15.00
12.00
3.00
Pond routing
Hyd. No. 3 -- 100 Year
Q (cfs)
21.00
18.00
15.00
12.00
3.00
0.00 0.00
0 120 240 360 480 600 720 840 960 1080 1200 1320 1440
Time (min)
— Hyd No. 3 Hyd No. 2 Total storage used = 9,925 cult

Hydraflow Table of Contents
Dunn NC drainageBA.gpw
Hydraflow Hydrographs Extension for Autodesk0 Civil 3DO by Autodesk, Inc. v2020
Thursday, 10 / 27 / 2022
Watershed Model Schematic...................................................................................... 1
- Year
SummaryReport......................................................................................................................... 2
HydrographReports................................................................................................................... 3
Hydrograph No. 3, Reservoir, Pond routing............................................................................. 3
PondReport - <New Pond>................................................................................................. 4
10 -Year
SummaryReport......................................................................................................................... 5
HydrographReports................................................................................................................... 6
Hydrograph No. 3, Reservoir, Pond routing............................................................................. 6
100 - Year
SummaryReport......................................................................................................................... 7
HydrographReports................................................................................................................... 8
Hydrograph No. 3, Reservoir, Pond routing............................................................................. 8