ABCC Flood Plain Compensatory Storage I
Taylor FE W hite,
O 9556 Historic Kings Road S Suite 102
Civil sign & Consulting Engineers twills. Florida 5
t X904) 346 -06 346 -0671 -f: (904) 346 -30-3051 1
www.TaylorandWhite.com
December 23, 2014
Mr. Rick Wood
Atlantic Beach Partner, LLC
414 Old Hard Road, Suite 502
Fleming Island, Florida 32003
RE: Atlantic Beach Country Club
100 -yr Flood Plain Compensatory Storage
Taylor & White, Inc. (T&W) Project No. 12210
Mr. Wood,
Pursuant to the Easement and Flood Plain Compensation Agreement ( "The Agreement ")
between Selva Marina Country Club, Inc., and Selva Preserve, LLC, please accept this letter as
adequate documentation that all of the requirements outlined within The Agreement have been
met. During the design and permitting of the development, Taylor & White, Inc., prepared the
Flood Plain Compensation calculations showing the existing flood plain storage and the
proposed flood plain storage across the development.
Due to historical flood issues across the existing Selva Marina golf course, additional treatment
basins were provided to better concentrate the flooding and to provide additional storage for the
100 -yr Flood Plain. In addition, there was an extra 30,000 cubic yards of Flood Plain
Compensation to be allocated to the future Selva Preserve development.
Based on the provided survey and topographical information, there was approximately 44,188
cubic yards of available storage within the 100 -yr Flood Plain throughout the existing golf
course. With the redesign of the development, the treatment basins, new stormwater ponds
and existing pond expansions, the proposed Atlantic Beach Country Club development will
provide approximately 96,276 cubic yards of storage within the 100 -yr Flood Plain. This
provides an excess of approximately 52,088 cubic yards of storage, of which 30,000 cubic yards
is allocated to the future Selva Preserve development.
Attached for your reference and file are copies of the existing and proposed 100 -yr Flood Plain
calculations.
Should you have any questions, please do not hesitate to give me a call.
Sincerely,
Taylor & White, Inc.
7
D. G ynn Taylor, P.E.
President
T: \2012 \12210 Selva Marina Country Club \Memos Letters \Let of Compensatory Storage_Wood_12- 23- 14.docx
Atlantic Beach Country Club
Existing 100 -Yr. Flood Plain Calculations
AREA #1 = Flood Plain Storage provided within Golf Course
Volume Method used is the Half Method V = (A * L)12
A from EL = 7.0 - 6.0 = 483849.8 ft ^2
100 -yr Floodzone EL.= 7.0 ft V = 120,962.45 cu.ft.
Average Existing Grade= 6.5 ft
0.5 ft
A from EL = 6.0 - 5.0 = 534662.0 ft ^2
100 -yr Floodzone EL.= 7.0 ft V = 400,996.50 cu.ft.
Average Existing Grade= 5.5 ft
1.5 ft
A from EL = 5.0 - 4.0 = 323830.7 ft^2
100 -yr Floodzone EL.= 7.0 ft V = 404,788.38 cu.ft.
Average Existing Grade= 4.5 ft
2.5 ft
A from EL = 4.0 - Creek = 25192.8 ft ^2
100 -yr Floodzone EL.= 7.0 ft V = 40,938.30 cu.ft.
Average Existing Grade= 3.8 ft
3.3 ft
(Total Volume Area #1 = 967,685.63 cu.ft.
35,840.21 cu.yd
AREA #2 = Floodplain storage within ponds
Pond Horseshoe #2 East -West (assume 4:1 side slopes)
Cumulative Cumulative
Description Elevation Area (AC) Volume Volume (AC -FT) Volume (CF)
TOB 6.00 1.46 0.71 0.71 30,960.05
Ex. Water Level 5.50 1.38 0.00 0.00
Bottom 1.00 0.61 0
Note: Volume available from Ex. Water Level to Top of Bank
Pond #3 North - South (assume 4:1 side slopes)
Cumulative Cumulative
Description Elevation Area (AC) Volume Volume (AC -FT) Volume (CF)
TOB 8.00 1.57 0.00 1.67 72,543.37
100 -yr Flood El. 7.00 1.42 1.67 1.67
Ex. Water Level 5.75 1.24 0.00 0.00
Bottom 0.50 0.47 0
Note: Volume available from Ex. Water Level to 100 -yr Floodplain Elevation
Ex. Linkside SWMF - 1
Cumulative Cumulative
Description Elevation Area (AC) Volume Volume (AC -FT) Volume (CF)
TOB 7.00 1.08 2.80 2.80 121,902.66
Ex. Water Level 4.10 0.85 0.00 0.00
Bottom 0.10 0.53 0
Note: Volume available from Ex. Water Level to Top of Bank
Total Volume Area #2 = 225,406.08 cu.ft.
8,348.37 cu.yd
'Total Volume Existing = 1,193,091.71 cu.ft.
44,188.58 cu.yd
Atlantic Beach Country Club
Proposed 100 -Yr. Flood Plain Calculations
AREA #1 = Flood Plain Storage provided within Ponds
S WM F-4
Cumulative Cumulative
Description Elevation Area (AC) Volume Volume (AC -FT) Volume (CF)
TOB 7.50 4.19 9.32 406,088.10
100-y Flood El. 7.00 3.76 4.67 9.32
Elevation 5.50 2.47 4.65 4.65
Normal Water Level 3.50 2.18 0.00 0.00
Bottom -3.00 1.02 0
Note: Volume available from Normal Water Level to 100-yr Floodplain Elevation
S WM F-6
Cumulative Cumulative
Description El evation Area (AC) Volume Volume (AC -FT) Volume (CF)
TOB 9.75 0.96 0.83 36,192.23
100-yr Flood El. 7.00 0.72 0.83 0.83
N WL 5.75 0.61 0.00 0.00
MAX BOTTOM -5.25 0.08 0
Note: Volume available from Normal Water Level to 100-yr Floodplain Elevation
Modified Linkside SWMF -1
Cumulative Cumulative
Description Elevation Area (AC) Volume Volume (AC -FT) Volume (CF)
100-yr Flood El. 7.00 2.15 4.31 5.78 251,711.46
Control Elevation 4.89 194 0.75 1.46
Elevation 4.50 1.90 0.72 0.72
Normal Water Level 4.10 1.68 0.00 0.00
Bottom -7.50 1.00 0
Note: Volume available from Normal Water Level to 100-yr Floodplain Elevation
(Total Volume Area #1 = 693,991.79 cu.ft.
= 25,703.40 cu.yd
Atlantic Beach Country Club
Proposed 100 -Yr. Flood Plain Calculations
AREA #2 = Floodplain storage within Golf Course Depressions
TB -7
Cumulative Cumulative
Description Elevati on Area (AC) Volume Volume (AC -FT) Volume (CF)
TOB 7.00 2.05 3.94 3.94 171,517.50
Bottom 4.50 1.10 0
Note: Volume available from Bottom of Basin to 100•yr Floodplain Elevation
TB-8
Cumulative Cumulative
Description Elevation Area (AC) Volume Volume (AC -FT) Volume (CF)
TOB 7.00 8.05 16.71 16.71 727,996.50
Bottom 4.50 5.32 0
Note: Volume available from Bottom of Basin to 100-yr Floodplain Elevation
TB -9
Cumulative Cumulative
Description Elevation Area (AC) Volume Volume (AC -FT) Volume (CF)
TOB 7.00 5.47 11.18 11.18 486,783.00
Bottom 4.50 3.47 0
Note: Volume available from Bottom of Basin to 100-yr Floodplain Elevation
TB -10
Cumulative Cumulative
Description Elevation Area (AC) Volume Volume (AC -FT) Volume (CF)
ELEVATION 7.00 1.02 1.98 1.98 86,031.00
Bottom 4.50 0.56 0
Note: Volume available from Bottom of Basin to 100-y Floodplain Elevation
TB -11
Cumulative Cumulative
Description Elevation Area (AC) Volume Volume (AC -FT) Volume (CF)
100-YR Floodplain 7.00 2.00 0.95 3.62 157,578.30
TOB 6.50 1.79 2.67 2.67
Bottom 4.50 0.88 0
Note: Volume available from Bottom of Basin to 100-y Floodplain Elevation
TB -12
Cumulative Cumulative
Description Elevation Area (AC) Volume Volume (AC -FT) Volume (CF)
100-YR Floodplain 7.00 2.00 0.95 3.70 160,954.20
TOB 6.50 1.78 2.75 2.75
Bottom 4.50 0.97 0
Note: Volume available from Bottom of Basin to 100-yr Floodplain Elevation
(Total Volume Area #2 = 1,790,860.50 cu.ft.
= 66,328.17 cu.yd
Atlantic Beach Country Club
Proposed 100 -Yr. Rood Plain Calculations
AREA #3 = Flood Plain Storage provided within Golf Course
Volume Method used is the Half Method V= (A * L) /2
North of Main Drke
A from EL = 7.0 - 5.0 = 78803.3 ft^2
100-yr Floodzone EL.= 7.0 ft V= 39401.66 cu.ft.
A\,erage Existing Grade= 6.0 ft
1.0 ft
A from EL = 5.0 - Creek= 23755.6 ftA2
100-yr Floodzone EL.= 7.0 ft V= 29694.5 cu.ft.
AA,erage Existing Grade= 4.5 ft
2.5 ft
South of Main Drk,e
A from EL = 7.0 - 5.0 = 17416.4 ft^2
100-yr Floodzone EL.= 7.0 ft V= 8708.2 cu.ft.
Po,erage Existing Grade= 6.0 ft
1.0 ft
A from EL = 5.0 - Creek= 29454.3 ftA2
100-yr Floodzone EL.= 7.0 ft V= 36817.875 cu.ft.
AN,erage Existing Grade= 4.5 ft
2.5 ft
'Total Volume Area #3 = 114,622.24 cu.ft.
4,245.27 cu.yd
'Total Volume Proposed = 2,599,474.53 cu.ft.
96,276.83 cu.yd
'Total Volume Existing = 1,193,091.71 cu.ft.
= 44,188.58 cu.yd
'Total Excess Storage = 1,406,382.82 cu.ft.
= 52,088.25 cu.yd
Additional Flood Plain Storage provided for Selva Preserve Development
1 CompensatoryVolume Provided = 810,000.00 cu.ft.
30,000.00 cu.yd
'Total Excess Storage = 596,382.82 cu.ft.
22,088.25 cu.yd