715 Amberjack Ln RESO24-0058 TAYLOR DUVAL STORMWATER VOLUME CALCULATIONS (2) (1) 06.17.2024Comp. By:
Date:5/10/2024
Public Works Department
City of Atlantic Beach
Permit No:
Address:
Required Storage Volume
Criteria:
Section 24-68 of the City of Atlantic Beach's Zoning, Subdivsion, and Land Development Regulations requires
that stormwater runoff from impervious areas be stored onsite. Volume to be retained is as follows:
V = CAR/12 which is the Modified Rational Method for estimating stormwater runoff
Where: V = Volume of Runoff to be stored (cubic feet)
C = Runoff Coefficient, 0.92, the difference between impervious area (C=1.0)
and undeveloped conditions (C=0.08).
A = Impervious Area (square feet)
R= 25-yr / 24-hr rainfall depth (9.3 inches for Atlantic Beach)
Onsite Storage Volume Required for Impervious Area:
Lot Area = 7,500 ft2
Impervious Area (A) = 2,962 ft2 =39%
V = 0.92 x 2,962.0 x9.3/ 12
V = 2,112 ft3
Provided Storage:
Area 1 - Relative Elev. Area Storage Sideslope:3 :1
(ft) (ft
2) (ft
3)
12.1 110 BOTTOM size:36.98 X 2.98
14.8 1,007 TOB size:53 X 19
Area 2 - Relative Elev. Area Storage
(ft) (ft
2) (ft
3)
0.0 0 BOTTOM size:0 X 0
0.0 0 TOB size:0 X 0
Area 3 - Relative Elev. Area Storage
(ft) (ft
2) (ft
3)
0.0 0 BOTTOM size:0 X 0
0.0 0 TOB size:0 X 0
Inground Storage: = A*d/pf
Total Storage Area at TOB (A) =1007.0 ft2
Depth to ESHWT from BOTTOM (d) =2.1 ft, default is 2.0 ft, verify onsite ESHWT
Pore Factor (pf) = 0.3 default is 0.4
Inground Storage Provided =634.4 ft3
Required Treatment Volume =2,112 ft3
Supplied Treatment Volume =2,126 ft3
Scott Walker PE
1,491
0
0
ATLANTIC BEACH, FLORIDA 32233
715 AMBERJACK LANE,
Retention W.R. for sending (Working Copy) 5/28/2024