93 GARDEN Copy of Water Retention_12-1-22 (1)Public Works Department
City of Atlantic Beach
Required Storage Volume
Permit No:
Address:
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
Where:
Onsite Storage Volume Required for Impervious Area:
Lot Area =
Impervious Area (A) =
V =
V =
Provided Storage:
Area 1 - Relative Elev.
(ft)
0
1
Area 2 - Relative Elev.
(ft)
0
1
Area 3 - Relative Elev.
(ft)
0
1
Area 4 - Relative Elev.
(ft)
0
1
Area 5 - Relative Elev.
(ft)
0
1
Inground Storage:
Required Treatment Volume =
Supplied Treatment Volume =
Comp. By:
Date:
RES22-0253
93 Garden Court, Atlantic Beach, FL 32233
which is the Modified Rational Method for estimating stormwater runoff
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)
6777
3049
0.92
2173.937
Area
(ft2)
0
273
Area
(ft2)
0
723
Area
(ft2)
0
290
Area
(ft2)
0
148
Area
(ft2)
0
153
= A*d/pf
Total Storage Area at TOB (A) =
Depth to ESHWT from BOTTOM (d) =
Pore Factor (pf) =
Inground Storage Provided =
1/6/2023
ft2
ft2 =
x
ft3
Storage
(ft3)
136.5
Storage
(ft3)
361.5
Storage
(ft3)
145
Storage
(ft3)
74
Storage
(ft3)
76.5
1587
2.25
0.4
1428.3
2173.937
2221.8
0.449904087354287
3049
BOTTOM
TOB
BOTTOM
TOB
BOTTOM
TOB
BOTTOM
TOB
BOTTOM
TOB
ft2
ft, default is 2.0 ft, verify onsite ESHWT
default is 0.4
ft3
ft3
ft3
x
Sideslope:
size:
size:
size:
size:
size:
size:
size:
size:
size:
size:
9.3
2
-4
-4
0
-4
0
-4
0
-4
0
/
:1
X
X
X
X
X
X
X
X
X
X
12
-4
-4
0
-4
0
-4
0
-4
0
ESHWT
30
25
59
24
24
Per Soils Report
Assumed Standard
Assumed Standard