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HomeMy WebLinkAboutIII-Tab 4 Site Utility Study• • BRICKELL VIEW TERRACE MAJOR USE SPECIAL PERMIT SITE UTILITY STUDY Prepared for: Brickell Holdings Group, LLC Prepared by: Consulting Engineering and Science, Inc. January 30, 2006 • • 1. General A. Project Location and Size: The project is located along the north side of S.W. 10th Street in the City of Miami; bounded on the east by S.W. 1st Court; bounded on the north by S.W. 9th Street; .and, bounded on the west by privately held property. The site has a total area of 50,382 square feet, or 1.16 acres. The site has approximately 200 feet of frontage along S.W. 10th Street Road; approximately 300 feet of frontage along S.W. 1st Court; and, approximately 200 feet of frontage along S.W. 9th Street. The land on which the project is proposed consists of three (3) parcels, identified with Miami -Dade County tax folio numbers 01- 0207-000-1020/1150/1160. A legal description of the property is as follows: Lot 1, 2, 3, 4, 17, 18, 19 & 20, Block 70S of MIAMI KNOWLTON'S SUBDIVISION, according to the plat thereof, as recorded in Plat Book B, at Page 41, of the Public Records of Miami -Dade County, Florida. LESS A portion of Lots 1, 2, 3 & 20, Block 70S of MIAMI KNOWLTON'S SUBDIVISION, according to the plat thereof, as recorded in Plat Book B, at Page 41, of the Public Records of Miami -Dade County, Florida, more particularly described as follows: Commence at the Northeast corner of said Lot 3; thence South along the East line of said Lot 3 for a distance of 22.25 feet; thence S89-58-01W for a distance of 16.02 feet to the POINT OF BEGINNING; thence S00-01-59E for a distance of 31.64 feet; thence N89-59-04E for a distance of 1.00 feet; thence SOO-01- 59E for a• distance of 128.83 feet; thence S89-58-01W for a distance of 21.13 feet; thence NOO-01-59W for a distance of 3.60 feet; thence 589-58-OIW for a distance of 39.50 feet; thence N00-01-59W for a distance of 159.40 feet; thence N89-58- OlE for a distance of 25.90 feet; thence S00-01-59E for a distance of 2.60 feet; thence N89-58-01E for a distance of 33.70 feet to the POINT OF BEGINNING. -1- • A portion of the site is currently occupied by an at -grade paved parking lot; and, a portion of the site is currently vacant. B. The proposed pro-iect build -out will be as follows: Residential: Retail: 119 units 900 sf Net Lot Area 50,382 sf, or 1.16 acres Gross Lot Area 93,632 sf, or 2.15 acres Construction will consist of one (1) residential tower of 23 floors, including a ground level, 5 levels of parking, 2 levels of amenities and 18 levels containing 119 condominium units; and, one (1) parking garage of 7 levels. -2 • • 2. Drainage A. Drainage Area Upon development, approximately 85 per cent of the site will be impervious and approximately 15 per cent of the site will be pervious. Stormwater runoff will consist of rainfall from the building roofs, driveways, walkways, landscape areas and one-third of the vertical building surfaces. The coefficient of runoff is calculated as follows: 85.0% (impervious) X 0.90 + 15.0% (pervious) x 0.20 Overall coefficient D. Existing Storm Drainage System 0.77 0.03 0.80 In the improved portion of the site, runoff 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. In the unimproved portion of the site, rainfall percolates directly into the surface of the vacant land. C. Proposed Storm Drainage System The storm drainage system to serve this project will be designed to direct the 5-year 1-day storm event to on -site retention/exfiltration systems and to contain the 25-year 3- day storm event on -site, as required to comply with the applicable requirements of the Miami -Dade County Department of Environmental Resources Management (DERM). While exfiltration trenches will be reviewed for feasibility at this location, it is anticipated that the stormwater disposal system will include two (2) 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 walkways will be diverted through baffled pollution control structures which will capture the oils and greases prior to flowing into the wells. -3- • • Table 1 Preliminary Drainage Calculations 1. Total Net Area 1.16 Acres a. Impervious Roof/Driveways/Walks 0.99 Acres 1/3 Vert. Bldg. Surface 1.19 Acres Total 2.18 Acres b. Pervious 0.17 Acres c. Adjusted Contributing Area 2.35 Acres 2. Adjusted Runoff Coefficient 2.18(0.9)+ 0.17(0.2) 2.35 = 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)(2.35) = 10.99 cfs Assume each 24-inch diameter drainage well has a capacity of 1,000 gpm per foot of head; and, using 2.5 feet of available head: Well Capacity = 1,000 gpm x 2.5 feet = 2,500 gpm per well - 5.57 cfs per well No. Wells = Peak Runoff = 10.99 cfs - 1.97 wells Well Capacity 5.57 cfs Provide two (2) - 24" diameter Drainage Wells Detention Tanks: Provide 1.5 minutes of detention time of storage in detention tanks: Volume of tanks required to handle 10.99 cfs for 1.5 min. 10.99 cfs x 1.5 min x 60 sec/min = 990 cubic feet (cf) Provide two (2) tanks (one with each well) with the following approximate interior dimensions: 2 times 6'-8" (width) x 15' (length) x 5' (depth) = 1,000 cf -4- • 3 Water Distribution The project is located in the water service area of the Miami - Dade Water and Sewer Department (WASD). Existing water mains in adjacent streets are 2-inch and 8-inch, neither of which is typically capable of providing the required domestic and fire flow required for this project. As such, it is anticipated that WASD and the Fire Department will require off -site water system improvements to provide water service and fire protection to this project. The water and fire service connections to this project will be made from those new water main improvements. The connections will consist of domestic water services, fire line services and cooling tower/irrigation water service, as applicable. 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. Table 2 Water Usage Residential Condominiums: 119 units @ 200 gpd/unit Retail: 900 sf @ 5 gpd/100 sf 23,800 gpd 45 gpd Total = 23,845 gpd -5- 4 Sanitary Sewer The project is located in the sewer service area of the Miami - Dade Water and Sewer Department (WASD). WASD currently has 8- inch, 10-inch and 12-inch gravity sewer mains located in the adjacent streets which appear to have adequate capacity to serve this project. It is anticipated that new sewer laterals will need to be installed from those existing sewer mains to serve this project. Flow from this project will be directed to WASD pump station PS-01 which currently has sufficient available capacity to serve this project. Therefore, it is anticipated that no new pump station will be required to serve this 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 (16.6 x 2.0) 23,845 gpd 16.6 gpm 33.2 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 Solid Waste Department. 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 Units: Solid Waste Retail: Solid Waste - 119 units x 1.42 tons/unit/year - 169 tons/year • 0.46 tons/day 920 lbs/day - 900 sf x 3.08 lbs/sf/year - 2,772 lbs/year 8 lbs/day Total - 928 lbs/day The project is located in the water and sewer service area of the Miami Dade Water and Sewer Department (WASD). -7-