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HomeMy WebLinkAboutSite Utility Study• MIXED -USE PROJECT 3760 BIRD ROAD SITE UTILITY STUDY Prepared for: H & H Development, Inc. Prepared by: Consulting Engineering and Science, Inc. October 28, 2005 • • 1. General A. Project Location and Size: The project is located along the south side of Bird Road (S.W. 40th Street); bounded on the west by S.W. 38th Avenue; on the south by Peacock Avenue and on the east by S.W. 37th Court in the City of Miami. The site, with an area of 76,083 square feet, or 1.75 acres, has approximately 277 feet of frontage along Bird Road (S.W. 40th Street), approximately 268 feet of frontage along S.W. 38th Avenue, approximately 277 feet of frontage along S.W. 37th Court and approximately 278 feet of frontage along Peacock Avenue. The site is currently occupied by a single story car dealership with at -grade parking. B. The proposed project build -out will be as follows: Condominiums: Office: Retail: Site Area : 254 units 67,800 sf 19,600 sf 76,083 sf, or 1.75 acres Construction will be a mixed use multi -story building including residential, office and retail uses with interior parking. Access will be from, S.W. 38th Avenue, Peacock Avenue and S.W. 37th Court. 2. Drainage A. Drainage Area Upon development, 90 percent of the site will be impervious and 10 percent of the site will be pervious. Stormwater runoff will consist of rainfall from the building roof, 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 trenches/exfiltration trenches. 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 (SrWMD). It is anticipated that the stormwater disposal system will include two (2) 24- inch 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 a. Impervious Area Roof/Decks/Walks 1/3 Vert. Bldg. Surface 1.75 Acres 1.57 Acres 0.86 Acres 2.43 Acres b. Pervious Area 0.18 Acres c. Adjusted Contributing Area 2.61 Acres 2. Average Runoff Coefficient 2.43(0.9) 0.18(0.2) 2.61 = 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)(2.61) 12.20 cfs -2- • • Assume each 24-µinch diameter drainage well has a capacity of 750 gpm per foot of head; and, 4.00 feet of available head: Well. Capacity = 750 gpm x 4.00 feet = 3,000 gpm per well 6.68 cfs per well No. Wells = Peak Runoff w 12.20 cfs = 1.83 wells Well Capacity 6.68 cfs Provide two (2) - 24-inch 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)(1.75) = 8.18 cfs Volume of tank required to handle 8.18 cfs for 90 seconds: V = 8.18 cfs x 90 sec = 736 cubic feet (cf) Provide two (2) tanks with the following interior dimensions: V = (2)[6'-6" (width) x 12' (length) x 5' (depth)] = 780 cf 3. Water Distribution The Miami -Dade Water and Sewer Department (WASD) owns and operates a 48-inch, a 42-inch, a 12-inch and an 8-inch water main located in Bird Road (S.W. 40th Street); a 12-inch and a 4-inch water main located in S.W. 37th Court; a 12-inch water main located in Peacock Avenue; and, a 6-inch main located in S.W. 38th Avenue. WASD has indicated that no off -site water main extensions will be required to serve this project. They have further indicated that the water and fire connections for this project are to be made from the existing 12-inch water main located in S.W. 37th Court or the existing 12-inch water main located in Peacock Avenue. 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. -3- • • The calculations for anticipated water usage required for this project are shown below in Table 2. Table 2 Water Usage Residential Condominiums: 254 units @ 200 gpd/unit Office: 67,800 sf @ 10 gpd/100 sf Retail: 19,600 sf @ 5 gpd/100 sf Total 50,800 gpd 6,780 gpd 980 gpd 58,560 gpd 4. Sanitary Sewer The Miami -Dade Water and Sewer Department (WASD) owns and operates 10-inch gravity sewer mains located in S.W. 38th Avenue and in Peacock Avenue; and, a 36-inch gravity sewer main located in S.W. 37th Court. WASD has indicated that no off -site sewer main extensions will be required to serve this project. They have further indicated that gravity sewer connections to the 10-inch gravity sewer main located in S.W. 38th Avenue and/or the 10-inch gravity sewer main located in Peacock Avenue will be made to serve this project. An on -site pump station will not 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) Average Daily Flow Peak Flow (ADF x 2.0) -4- 58,560 gpd 41 gpm 82 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. The projected daily volumes of solid waste generation are shown below, in Table 4. Table 4 Solid Waste Generation Residential Condominiums: Solid Waste - 254 units x 1.42 tons/unit/year 361 tons/year 0.99 tons/day 1,980 lbs/day Office: Solid Waste Retail: Solid Waste 67,800 sf @ 3.08 lbs/sf/year 208,824 lbs/year 572 lbs/day 19,600 sf @ 3.08 lbs/sf/year 60,368 lbs/year 165 lbs/day Total - 2,717 lbs/day -5-