HomeMy WebLinkAboutWPO201900052 Other 2020-02-18 (10)Pond Treatment Volume Summary
Proposed Wet Pond
Project Name: Berkmar Drive Apartments
Timmons Group Project No. 42297
Date: 02/07/2020
Calculated By: Cameron Morgan
Stormwater Treatment Parameters
TIMMONS GROUP
YOUR VISION ACHIEVED THROUGH OURS.
Data Input
Notes and Descriptions
Water Quality Rainfall Depth, P
1.00 inches
Precipitation depth for water quality storm
On -site Drainage Area, ATR
(for treatment credit)
537,970 SF
12.35 AC
On -site area draining to pond, counted towards treatment credit
On -site Impervious Area
(for treatment credit)
346,300 SF
7.95 AC
On -site post -development impervious area received by pond
Percent Impervious
64.4 %
Weighted Runoff Coefficient, Rv
0.68
See derivation below
Time of Concentration, Tc
11 minutes
0.18 hours
Weighted Runoff Coefficient (Rv) Derivation
Forest/Open Space
Managed Turf
Impervious Cover
Weighted
Rv
HSG
SF
Acres
Rv
HSG
SF
Acres
Rv
HSG
SF
Acres
Rv
A
0.02
A
18,730
0.43
0.15
A
39,200
0.90
0.95
B
0.03
B
172,940
3.97
0.20
B
307,100
7.05
0.95
0.68
C
0.04
C
0.22
C
0.95
D
0.05
D
0.25
D
0.95
Treatment Volume Calculation
Data Input
Notes and Descriptions
Treatment Volume, Tv, Required 30,532 CF
P
(i.e. Wet Storage) 0.70 AC -FT
T" —ATR * Rv * (12 in/ft)
Treatment Volume, Tv, Provided 49,300 CF
(i.e. Wet Storage) 1.13 AC -FT