SW4240501_Design Calculations_20240819 (2)

WET POND#2 DESIGN WORKSHEET
Project: Reserve at Old Hollow
Date: 8/15/2024
Drainage Area(A)= 6.36 Ac.
Built-Upon Area= 3.72 Ac.
Design Volume(DV):
IA=Built-Upon/Drainage= 58.5%
Rv=0.05+0.9xIA= 0.5764
Design Volume(DV)= 3630 x RD x Rv x A= 13,307 cu ft
Main Pool Design:SA/DA Table
Average Depth: 3 ft
Interpolated SA/DA Ratio: 2.04
Surface Area(SA)=
SA/DA*DA/100*43,560 sqft= 5652 sq ft
Provided SA(Elevation=942)= 5,878 sq ft
Drawdown Time:
Cd=Coefficient of Discharge= 0.6 (0.6 typical)
Orifice Diamter(in)= 1.5 in
A=Area of Orifice= 0.01227 sqft
Depth of Design Volume= _ 1.7 ft
Ho=Depth of Water Quality Volume/3 0.566666667 ft
Q=Cd*A(2*g*H0)1/2= 0.0445 cfs
Drawdown Time=DV/Q/3600/24= 3.5 days
Average
Elevation Area Area Volume
938 74
FOREBAY SEDIMENT STORAGE 938-939 �7.5
939 245
939 245
517 517
FOREBAY 939-942 940 789
1,222 2443
942 1654
TOTAL 3119.5 (17.19%main pool)
935 1019
SEDIMENT STORAGE 935-936 1,200 1199.5
936 1380
1380
1,825 3650
938 2270
PERMANENT POOL 936-942 (VEGETATED 2,854 5707
SHELF 941-942) 940 3437
3,785 3785
941 4133
5,006 5005.5
942 5,878
TOTAL 18148
942 7,532
8,076 8,076
DESIGN VOLUME 942-943.7 943 8,620
9,019 6,313
943.7 9,418
TOTAL 14389
WATER QUANTITY 943.6-948 943.7 9,418
(TOP OF DAM) 12,170 52,331
EMERGENCY SPILLWAY-945.0 948 14,922