HomeMy WebLinkAboutSite Utility Study•
•
•
BISCAYNE BAY LOFTS
(ONYX)
MAJOR USE SPECIAL PERMIT
SITE UTILITY STUDY
Prepared for:
Biscayne Bay Lofts, LLC
Prepared by:
Bermello, Ajamil & Partners, Inc.
November 7, 2003
•
BISCAYNE BAY LOFTS (ONYX)
MAJOR USE SPECIAL PERMIT
SITE UTILITY STUDY
Prepared for:
BAP Development, Inc.
Prepared by:
Bermello, Ajamil & Partners
September 24, 2003
•
•
BISCAYNE BAY LOFTS (ONYX)
SITE UTILITY STUDY
I. DRAINAGE
A. Drainage Area
The site is located east of Biscayne Blvd., adjacent to Biscayne Bay, between NE 25th
Street and NE 26th Street. It has approximately 250 ft of frontage on NE 25th Street and
135 ft of frontage on NE 26th street with some 210 ft of frontage on Biscayne Bay. It
consists of a total of ±1 acre.
After development, approximately 95% of the site will be impervious areas and
approximately 5% of the site will remain as pervious areas. The storm water discharge
will consist primarily of building roofs, driveways and landscape areas run-off. The
coefficient of run-off is arrived at as follows:
0.95 (impervious) x 0.90
+0.05 (pervious) x 0.30
overall coefficient
B. Existing Drainage System
0.855
0.015
0.87
The City of Miami presently maintains a roadway drainage system in both side streets.
The site is presently fully developed. The existing roadway system appears to be of
sufficient capacity to handle the present conditions.
C. Proposed Drainage System
The primary drainage system of this building will consist of drainage wells that will allow
the stormwater runoff to be fully contained on -site. No off -site runoff is expected from
this building. It is anticipated that two drainage wells will be sufficient to handle the
runoff (See Table 1 for drainage calculations).
The stormwater will be collected thru a system of catch basin inlets and transported by
pipes to the well locations. The wells will allow the stormwater to flow into the Biscayne
Aquifer. The wells will be designed to handle the stormwater runoff and tested for
capacity as they are installed, In addition, the subject parcel may have an emergency
discharge pipe to Biscayne Bay.
Runoff from driving surfaces such as driveways and parking areas will be diverted thru
detention structures which will capture the oils and greases prior to flowing into the wells.
Page 2
Table 1
Sample Drainage Calculations
(Phase 1 only)
Runoff Generations
1. Total Area
a. Impervious
b. Pervious
2. Average Runoff Coefficient
3. Design Storm
4. Time of Concentration
5. Rainfall Intensity
6. Peak Runoff (Q) - CA
1.00 Acres
95% or 0.95 Acres
5% or 0.05 Acres
(.95) (.9) + (.05) (.3) = 0.87
5 years
10.00 min
6.10 in/hr
(.87) (6.10) (1.00) = 5.31 CFS
Assume each 24" diameter drainage well flows at 750 gpm per foot of head - using 2
feet of head:
2 x 750 gpm = 1,500 gpm per well
1,500 gpm = 3.34 CFS
(Peak runoff)
(Flow per well)
5.31 CFS
3.34 CPS
Provide 2 - 24" diameter wells
Detention Tank:
Providing 11/2 minute detention time of storage in tank.
Volume of tank required to handle 1,500 gpm for 1.5 min.
1,500 gpm x 1.5 min = 2,250 gal/tank or 300 ft3 each
1.59 Wells
Provide 2 tanks, each one with the following interior dimensions:
5' (width) x 5' (height) x 12' (length) = 300 ft3
Provide 2 tanks with 300 ft3 volume each
II. WATER DISTRIBUTION
The Miami Dade Water and Sewer Department owns and operates one 12" water main located
on NE 25t' Street, and a 6" water main on NE 26th Street.
The water connections to serve the buildings will be done from the 12" water main. The
connections will consist of fire line supply, domestic water and irrigation water. No on -site wells
are planned for this project.
Page 3
•
•
•
The calculations for anticipated water volumes required for this project are shown below, in
Table 2.
Table 2
Water Volumes
ResidentialApartments
113 units @ 200gpd/unit 22,600 gpd
lll. SANITARY SEWER
The Miami Dade Water and Sewer Department owns and operates a
along both side streets with frontage on this property. It is anticipated
connection to one of the gravity lines will be sufficient to serve this project.
be built on -site to serve the project. Table 3, below, shows the ant
calculations.
Table 3
Sewage Flows
gravity sewer system
that a single gravity
No pump station will
icipated sewage flow
Average Flow (from Table 2) 22,600 gpd
Average Flow 16 gpm
Peak Flow (16 x 3.5) 56 gpm
IV. SOLID WASTE GENERATION
Solid waste generated by this project will be collected in standardized on -site containers for
refuse and recyclables. Regular pick-up service will be provided by either private hauling
companies and/or The City of Miami Solid Waste Department, which will transport the waste to
Metro -Dade County's Disposal or Recycling facilities.
The projected daily volumes of solid waste generation are shown in Table 4, below.
Table 4
Solid Waste Generation
Residential Apartments
(113 units @ 1.42 tons/units x 2,000 ibs/ton)/365 days 880 Ibs
Page 4