SW6191003_Calcs (Design Volume)_20191211

Hobson Road Concrete Plant Required Storm Volume
Pond #1
Drainage Area:
4.25 acres 185,328 sf
Impervious Area: 98,102 sf (2.25ac)
% Impervious: 53%
1 inch Storm Event:
Rv = 0.05+0.009 1
Rv = runoff coefficient
1= percent impervious
Rv=0.05+0.009*53%
= 0.527
For volume that must be controlled:
Volume=3,630*Rd*Rv*A
Volume = 3,630*(1 inch)*(0.527)*4.25 acres = 8,130 cf
SA/DA ratio is 1.88 for a depth of 3 feet
Required surface area = 4.25ac * (.0188) = 0.080 ac or 3,485 sf
Surface area provided = 7,690 sf
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