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Home My WebLink AboutSite Utility Study• • • MARQUIS Biscayne Boulevard and NE llth Street Site Utility Study CTE Project No. 04-042440.A Prepared by: CONSUL -TECH DEVELOPMENT SERVICES, INC. Florida Certificate of Authorization No. 9008 10570 N.W. 27th Street, Suite 101 Miami, Florida 33172 Tel. 305-599-3141 Fax. 305-599-3143 OCTOBER, 2004 • • • I. INTRODUCTION The proposed project site is located between NE 1 1th Street and 11t Terrace, and between Biscayne Boulevard and NE 2nd Avenue. The site area is 0.99 acres. The proposed project will include a 61-story residential tower with a parking garage and some retail areas. The tower will have a total of 296 condominium units, 14 townhouses and 48 room boutique hotel, and 5,765 SF area for a 200 seats restaurant. IL DRAINAGE SYSTEM For drainage design purposes, the site will be considered 100% impervious. Landscape and green areas are provided, but these areas will not be considered in the calculations in an effort to be conservative in the storm water management design. Storm water discharge will consist of runoff from rooftops, roadways, vertical building faces and pedestrian areas. Miami -Dade DERM requires that the proposed drainage system take into account 1/3 of the largest vertical building face. The building faces exposed to the south will produce the largest amounts of runoff and will be accounted for in the calculations. The site land use can be summarized as follows: Total Net Impervious Vertical Total Lot Area Area Building Faces Drainage Area (Acres) ,(Acres) (33%) (Acres) (Acres) 0.99 0.99 0.92 1.91 The proposed drainage plan calls for all pavement runoff to be collected in catch basins capable of detaining the peak inflow from the Miami -Dade County DERM 5-year, 24-hour design storm for 90 seconds. These basins also contain baffles to prevent all oil, grease and foreign matter from flowing into the proposed system. The runoff will then flow into three proposed drainage wells based on calculations found in Table 1. Runoff from building rooftops and vertical faces are uncontaminated by oil and grease and may be piped directly into to the drainage wells. The use of drainage wells is permitted by Dade County DERM in this area due to the high level of salinity found in the groundwater. Since the proposed system is using drainage wells to • • • dispose of excess runoff, an exfiltration trench system will be designed to treat the larger of the first inch of runoff generated before disposing of any runoff, or 2.5 inches over the impervious area. The proposed well and exfiltration trench systems will keep the site dry during the DERM 5 year - 24 hour storm. Biscayne Boulevard is a Florida Department of Transportation Right -of -Way. According to Department rules, additional calculations must be performed to prove to the Department that there will be no discharge into the State Right -of -Way. The drainage well system will be designed to retain the maximum storm stage of the 100-year, 1, 2, 4, 8, 24, 72, 168, and 240-hour storm events. III. WATER DISTRIBUTION MASTER PLAN The Miami -Dade Water and Sewer Department (MD-WASD) provides the water service in this area. Currently, there are two existing 24-inch water mains on Biscayne Blvd, a 12-inch water main on NE 2n Avenue, and a 6-inch water main on NE 11t' Street. No water mains exist along NE 11h Terrace. Refer to the attached Water Atlas for additional information. The MD-WASD will probably require the construction ofa newl2-inch water main along 1 1th Street and also along NE 11h Terrace. Nevertheless, because of the existing water mains along the Biscayne and NE 2nd Avenue, it is possible that MD-WASD, instead of requiring the construction of the water mains, will be content with a contribution for the construction of future water mains in the area. Depending on the requirements of MD-WASD, the water and fire line connections for this project will be provided from the existing or new 12-inch water main. At least one fire hydrant should be installed on the proposed water main. The anticipated average daily water consumption for the entire project is 77,500 GPD, and is calculated as shown in Table 2. • • • IV. SANITARY SEWER MASTER PLAN The Miami -Dade Water and Sewer Department (MD-WASD) also provides the sanitary sewer service in this area. There are existing 8-inch gravity sanitary sewer mains running along all the surrounding. Service to this project will be provided by sanitary laterals connected to the existing sewer mains. This project is anticipated to generate an average daily sewage flow of 77,500 GPD, and is calculated as shown in Table 2. The wastewater produced by the site will travel via the existing sanitary sewer system to the MD- WASD Regional Pump Station No. 2. Pump station No. 2 is currently operating for 5.06 hours per day. The additional 77,500 GPD will only increase the elapsed time by 0.05 hours to 5.11 hours per day. Thus, the pump station is deemed capable of handling the proposed flow from the project. Pump Station No. 2 transmits all flow directly to the MD-WASD treatment plant on Virginia Key for final treatment before discharge into the Atlantic Ocean. Refer to the attached Miami -Dade DERM projections for more information. V. SOLID WASTE GENERATION Solid waste generated will be placed in standardized on -site containers for refuse and recyclables per the City of Miami Code, for regular pickup by private hauling companies and/or the City of Miami Solid Waste Department. The solid waste will then be transported to Miami-Dade's Disposal Facilities. Actual waste pick-up locations will be shown in the architectural plans. This project is anticipated to generate an average daily solid waste volume of 552.9 Cu. Yd/month, and is calculated as shown in Table 3. Generation rates were determined from data provided by the Miami - Dade County Department of Solid Waste. • • • Total Net Lot Area Total Drainage Area 1. Impervious 2. Pervious TABLE 1 MARQUIS DRAINAGE CALCULATIONS = 0.99 Acres = 1.91 Acres = 100% or 1.91 Acres = 0% or 0.00 Acres 2. Average Runoff Coefficient = 0.98 3. SFWMD Design Storm Information 1. 5-Year 24-Hour Storm (Miami -Dade County W.C. 1.1) Rainfall Intensity = 6.20 inches per hour Purpose = Flood Protection Peak Runoff = CIA = (0.98)(6.20)(1.91) = 11.61 cfs 2. SFWMD 25 Year 72 Hour Storm (Miami -Dade County W.C. 1.1) Rainfall Intensity = 7.40 inches per hour Purpose = Perimeter Berm Peak Runoff = CIA = (0.98)(7.40)(1.91) = 13.85 cfs 3. FDOT 100 Year - 1 Hour Storm Rainfall Intensity = 5.10 inches per hour Purpose = Discharge to Biscayne Blvd. Peak Runoff = CIA = (0.98)(5.0)(1.91) = 9.36 cfs • • FDOT Design Storm Information Storm Duration 1 Hour 2 Hour 4 Hour 8 Hour 24 Hour 72 Hour 168 Hour 240 Hour 4. Well Data Rainfall Amount (Inches) 5.0 (Figures 5-1 & 5-11) 6.3 (Figures 5-1 & 5-11) 7.8 (Figures 5-1 & 5-11) 9.6 (Figures 5-1 & 5-11) 14.0 (Figure 5-13) 19.0 (Figures 5-14 & 5-15) 20.0 (Figure 5-16) 23.0 (Figure 5-17) 1. Well Diameter 2. Assumed Well Capacity 3. Mean High Tide Elevation 4. Specific Gravity Head Loss 5. Proposed Number of Wells 5. Hydraulic Grade Line Elevations at Well Structure = 24 Inches = 700 gpm/ft. of Available Head =1.50 ft. (taken from W.C. 20,034-A) = 2.00' =3 1. 5 Year DERM Storm = (11.61 cfs)/[(700 gpm/ft head)(0.002228 cfs/gpm)(3 wells)] + (1.50 + 2.00) = 5.98' NGVD 2. SFWMD 25 Year - 72 Hour Storm = (13.85)[(700 gpm)(0.002228 cfs/gpm)(3 wells)] + (1.50 + 2.00) = 6.46' NGVD 3. FDOT 100 Year - 1 Hour Storm = (9.36 cfs)[(700 gpm)(0.002228 cfs/gpm)(3 wells)] + (1.50 + 2.00) = 5.50' NGVD • • • TABLE 2 OPUS ANTICIPATED AVERAGE DAILY FLOW OF WATER AND WASTEWATER Residential Towers 296 condo units 14 townhouse units Boutique Hotel 48 rooms Retail / Restaurant 200 seats @ 200 gpd/unit = 59,200 gpd @ 250 gpd/unit — 3,500 gpd @ 100 gpd/unit — 4,800 gpd @ 50 gpd/seat = 10,000 gpd Total = 77,500 gpd ANTICIPATED AVERAGE DAILY FLOW WASTEWATER Average Flow _ 0.0775 mgd Peak Flow — 0.2713 mgd NOTES: 1. Peak flow uses a factor of 3.75 times average flow (Recommended Standards for Wastewater Facilities, 1990 Edition) 2. gpd = gallons per day 3. No industrial wastewater is anticipated to be generated 4. mgd = million gallons per day • • • TABLE 3 OPUS SOLID WASTE GENERATION Residential Towers 310 units @ 1.25 cu. yds /month per unit = 387.5 cu. yds./rnonth Boutique Hotel 48 rooms @ 1.25 cu. yds /month per unit = 60 cu. yds./month Retail / restaurant 5,765 SF of retail / rest space @ 0.25 cu. yds per 100 SF /month — 14.41 cu. yds/month Total anticipated Solid Waste generation = 462 Cu. Yds. /month • • • Pump Station Monthl Station..30 -0002 Atlas Py..E13 MIAMI DADE WATER & SEWER DEPARTMENT Addr..925 BISCAYNE BLVD Sec--Township-Range........ . ...31-53-42 Genr._ ET clock.Y Te1m.Y #Pumps. 5 Pump Type.A Stn Clae .M Speed.R Hr. pwr. Res flow(gpd) Plans.. 2,662,990 Plats.. 0 Extens. 0 Prof Napot 5.06 hrs 3.21 h r 3.21 hrs Cap 50.60 32.10 32.10 Date MO . NAPDT Avg Daily Flow Rgd 08/25/2004 3.38 07/27/2004 2.82 06/25/2004 2.79 11.16 0.00 05/26/2004 2.85 11.40 0.00 04/27/2004 3.17 12.67 0.00 03/29/2004 3.28 13.10 0.00 02/27/2004 3.25 12.98 _ 0.00 Information torium effective ea.nce / / <Plan Review Moratorium..0 Yearly 'APOT hr.........®® 3.21 :n Gr~oee Capaci.ty(gpd) .. 57,600,000 ation Reduction Factor....... 0.60 Stn Net Cap Certif(gpd).. 0 Stn Net Capacity(gpd).... 34,560,000 Indicated Flouis(gpd)..... 4,622,400 Fig Pr p 13.50 0.00 Y 5 11.28 0.00 Y 5 Signature..LEALG Ready. Comments 5 Sign Date..03/17/2003 13:52:24.01 • • • WATER ATLAS (MD-WASD) NN N.T5. • • SEWER ATLAS (MD-WASD) RICE