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HomeMy WebLinkAboutSite Utility Study• • • THE BLUE AT CORAL WAY SITE UTILITY STUDY PREPARED BY: MARLIN ENGINEERING, INC. 2191 N.W. 971.11. Avenue Miami, Florida 33172 Tel.: (305) 477-757 • THE BLUE AT CORAL WAY SITE UTILITY STUDY 1. STORM DRAINAGE A. Drainage Area The site is located at 3152 Coral Way some 250 feet east of S.W. 32nd Avenue abutting S.W 22nd Street (Coral Way) in the north and S.W. 22n` Terrace in the south. It runs along the south right of way line of Coral Way for approximately 250 feet and approximately 200 feet of frontage on the Southwest 22n`. Road. Its total area consists of 57,119 square feet or 1.311 acres, according to the Boundary Survey prepared and updated by Brownell and Associates, dated 5/19/03. The impervious post -development area is estimated to be 95% to approximately 5% of pervious area remaining. The stoini water discharge will consist primarily of building roofs, driveways and landscape areas runoff. The weighted coefficient of run-off will be calculated as: Impervious Area 0.95 x 0.90 = 0.855 Pervious Area 0.05 x 0.30 = 0.015 Weighted Coefficient Cw = 0.870 B. Existing Drainage System The municipal roadway drainage system in S.W. 22nd Terrace is maintained by the City of Miami which is implementing a drainage improvement program throughout the city limits, after the intense flooding conditions that occurred during Hurricane Irene and the No -Name Stoini. The stotni drainage system in S. W. 22nd Street (Coral Way) is maintained by the State of Florida D.O.T. Although the existing roadway system appears to be of sufficient capacity to handle the present conditions, it will be studied and evaluated as part of the civil engineering site development plans, and improvements recommended should they be required. C. Proposed Drainage System Due to the location of this building as well as on the its footprint and lack of green areas, its primary drainage system of this will consist of drainage wells which will allow the post -development storm water runoff to be fully contained on -site. No off -site runoff is anticipated from this building. Based upon the building layout and area information two drainage wells will be studied which we consider sufficient to handle the differential runoff (Post -development Q- Pre -development Q). Preliminary drainage calculations are included below. The well system will be designed to handle the calculated runoff and sized based upon the well testing capacity results provide by the well contractor specialist. • • Rainwater will be collected by rain water leaders and piped to catch basin inlets that will also collect groundwater runoff, and then piped and disposed into retention tanks that will capture the grease and oils, to achieve the local water quality standards set by the department of Environmental resources Management (DERM). These retention tanks will include within the same structure, the designed deep well for final disposal. The wells will allow the stoic i water to flow into the Biscayne Aquifer. The wells will be designed to handle the storm water runoff and tested for capacity as they are installed. PRELIMINARY DRAINAGE CALCULATIONS 1. Total area a. Impervious b. Pervious 2. Average Runoff Coefficient Cw 3. Design Storm Frequency 4. Time of Concentration 5. Rainfall Intensity 6. Runoff Q = CiA 1.311 Acres 95% or 1.245 Acres 5% or 0.066 Acres (0.95) + (0.9) + (0.05) (.3) = 0.87 5 years 10.00 min 6.10 in/hr (0.87) (6.10) (1.311) = 6.96 CFS Assume each 24" diameter drainage well / flows at 700 GPM/Ft. using 2 feet of head: 2 x 700 GPM = 1,400 GPM per well 1,400 GPM = 3.12 CFS Runoff Q 6.96 CFS = 2.23 Cap. Per Well 3.12 CFS Provide Two (2) — 24" diameter wells Detention Tank: Providing 1 V2 Minute detention time of storage in tank. Volume of tank required handling 1,400 gpm for 1.5 min. 1,400 gpm x 1.5 min = 2,100 Gal/tank or 281 Cu.Ft . each Provide 2 tanks each with the following interior dimensions: 5'-0" (width) x 5'-0" (height) x 12'-0" (length) = 300 Cu-Ft. • • • Provide Two (2) tanks with 300 Cu-Ft. capacities each. IL WATER DISTRIBUTION SYSTEM The Miami -Dade Water and Sewer Department WASD owns and operates a 24 inch water main running east -west in front of the property on S.W. 22nd Street (Coral Way), and two small 2 inch and 4 inch water mains on S.W. 22nd terrace. The water connections to serve the buildings will be done from the 24-inch main. Two (2) connections will be installed from said water main one (1) 6-inch fire protection line and one (1) 6-inch domestic water supply and landscape irrigation lines. Well water is not permitted at this property. The calculations for anticipated water volumes required for this project are shown below. WATER DEMAND CALCULATION Residential Apartments 190 units at 200 gpd/unit 38,000 Retail 4,135 Sq-Ft. at 5GPD/100 Sq-Ft. 208 TOTAL WATER DEMAND 38,208 GPD III. SANITARY SEWER DISPOSAL The Miami Dade Water and Sewer Department owns and operates a 10 inch gravity sewer line running east along S.W 22nd Street (Coral Way) and a second 10 inch gravity sanitary sewer line running west along S.W. 22nd Terrace, finally discharging the sewage into the Sanitary Sewer Pump Station # 152. An 8 inch sewer lateral will connect the building to the existing sanitary sewer line on S.W. 22'd terrace. No pump station is needed to provide the anticipated connection. The calculations for the anticipated wastewater generated by this project are shown below. SEWAGE DISCHARGE Average Flow (from water Calculations above) 38,208 GPD Daily Average Flow 26.53 GPD Daily Peak Flow (26.53x 3.5) 92.86 GPM