HomeMy WebLinkAboutSite Utility Study•
OASIS ON THE BAY
SITE UTILITY STUDY
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Prepared for:
The Related Group of Florida
Prepared by:
Consulting Engineering and Science, Inc.
October 6, 2005
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1. General
A. Project Location and Size:
The project is located along the north side of N.E. 79th
Street, bounded on the west by N.E. Bayshore Drive; on the
north by N.E. 80th Street and on the east by Biscayne Bay in
the City of Miami. The site, with a site area of 148,104
square feet, or 3.40 acres, has approximately 500 feet of
frontage along N.E. 79th Street, approximately 192 feet of
frontage along N.E. Bayshore ➢rive and approximately 580 feet
of frontage along N.E. 80th Street. The Florida Department of
Transportation (FDOT) is requiring that the existing access
from N.E. 79th Street onto N.E. Bayshore Court be closed.
Therefore, it is intended to vacate the portion of right-of-
way along N.E. Bayshore Court from N.E. 79th Street to N.E.
80th Street.
The site is currently occupied by multiple buildings with at -
grade parking.
B. The proposed project build -out will be as follows:
Condominiums:
Restaurant:
Site Area :
467 units
4,200 s.f.
148,104 s.f., or 3.40 acres
Construction will be two (2) residential buildings consisting
of 20-story structures each with residential units. One
residential building will include a restaurant at the ground
floor level fronting N.E. 80th Street.
2. Drainage
A. Drainage Area
Upon development, 88% of the site will be impervious and 12%
of the site will be pervious. Stormwater runoff will consist
of rainfall from the building roof, driveways, decks,
landscape areas and one-third of the vertical building
surface.
B. Existing Storm Drainage System:
Runoff from the site is currently directed to a number of
catch basins located throughout the existing parking areas
from which the runoff is directed to underground seepage
trench/exfiltration trenches.
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C. Proposed Storm Drainage System:
The storm drainage system to serve this project will be
designed to contain the 5-year 1-day storm event and the 25-
year 3-day storm event on -site, and will be designed to
protect the first floor elevations from the 100-year 3-day
storm event, as required to comply with the applicable
requirements of the Miami -Dade County Department of
Environmental Resources Management (DERM) and the South
Florida Water Management District (SFWMD). It is anticipated
that the stormwater disposal system will include five (5) 24"
drainage wells. See supporting calculations, in Table 1.
Runoff will be collected through a system of catch basins and
conveyed by pipes to the well locations.
Runoff from driving surfaces such as driveways and parking
areas will be diverted through baffled pollution control
structures which will capture the oils and greases prior to
flowing into the wells.
Table 1
Preliminary Drainage Calculations
1. Total Site Area 3.40 Acres
a. Impervious Area
Roof/Driveways/Walks 2.99 Acres
1/3 Vert. Bldg. Surface 2.05 Acres
5.04 Acres
b. Pervious Area
c. Adjusted Contributing Area
2. Average Runoff Coefficient
0.41 Acres
5.45 Acres
5.04(0.9)- 0.41(0.2)
5.45
0.85
3. Design Storm 5 years
4. Time of Concentration 15 minutes
5. Rainfall Intensity 5.50 in/hr
6. Peak Runoff (Q) = CiA (0.85)(5.50)(5.45)
25.48 cfs
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Assume each 24-inch diameter drainage well has a capacity of
750 gpm per foot of head; and, using 3.33 feet of available
head:
Well Capacity = 750 gpm x 3.33 feet = 2,497.5 gpm per well
5.56 cfs per well
No. Wells = Peak Runoff = 25.48 cfs = 4.54 wells
Well Capacity 5.56 cfs
Provide five (5) - 24" diameter Drainage Wells
Detention Tank: Provide 1.5 minutes (90 seconds) of detention
time of storage in tank for surface area only (excludes 1/3 of
the vertical building surfaces):
Q = (0.85) (5.50) (3.40) = 15.90 cfs
Volume of tank required to handle 15.90 cfs for 90 seconds.
= 15.90 cfs x 90 sec = 2,293 cubic feet (cf)
Provide five (5) tanks with the following interior dimensions:
5 x 6(width) x 12' (length) x 4' (depth) = 1,440 cf
3. Water Distribution
The Miami Dade Water and Sewer Department (WASD) owns and
operates a 6-inch water main located in N.E. Bayshore Drive;
12-inch water main located in N.E. Bayshore Court; 6-inch and
30-inch water main located in N.E. 79th Street; and, 12-inch
main located in N.E. 80th Street.
The water and fire connections for this project will be made
from the existing 12-inch water main located in N.E. Bayshore
Court. The connections will consist of a fire line service,
domestic water service and cooling tower/irrigation water
service. No on -site water wells are planned for this project.
The calculations for anticipated water usage required for this
project are shown below, in Table 2.
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Table 2
Water Usage
Residential Condominiums:
467 units @ 200 gpd/unit = 93,400 gpd
Restaurant:
210 seats @ 50 gpd/seat = 10,500 gpd
Total = 103,900 gpd
4. Sanitary Sewer
The Miami Dade Water and Sewer Department (WASD) owns and
operates 8-inch gravity sewer mains in N.E. Bayshore Drive,
N.E. Bayshore Court, N.E. 80th Street and within a utility
easement within the project site. It is anticipated that one
or two gravity sewer connections to one of these sewer mains
will be utilized to serve this project, and the existing sewer
main in the utility easement will be removed. No pump station
will be required to serve the project. Anticipated sewage
flow calculations are shown below, in Table 3.
Table 3
Sewage Flow Calculations
Average Daily Flow (Table 2) = 103,900 gpd
Average Daily Flow = 72.2 gpm
Peak Flow (72.2 x 2.0) = 145 gpm.
5. Solid Waste Generation
Solid waste generated by this project will be collected in
standardized on -site containers for refuse and recyclable
waste. Regular service will be provided by either private
hauling companies and/or the City of Miami or Miami -Dade
County Department of Solid Waste. Both will transport the
waste to Miami -Dade County's Disposal or Recycling facilities.
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The projected daily volumes of solid waste generation are
shown below, in Table 4.
Table 4
Solid Waste Generation
Residential Condominiums:
Solid Waste
Restaurant:
Solid Waste
467 units x 1.42 tons/unit/year
663 tons/year
1.82 tons/day
3,634 lbs/day
= 4,200 sf @ 0.0108 tons/sf/year
45.36 tons/year
249 lbs/day
Total = 3,929 lbs/day
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