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HomeMy WebLinkAboutSite Utility Study• • • OPUS Biscayne Boulevard and NE 13th Street Site Utility Study CTE Project No. 04-0424-40 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 APRIL, 2004 • • INTRODUCTION The proposed project site is located on the south side of NE 13th Street, between Biscayne Boulevard and N. Bayshore Drive. The site consists of three adjacent properties for net total of 0.82 acres. The east most property is currently occupied by an existing building that will be demolished. The other two properties are vacant land. The proposed project will include a 57-story residential tower with a parking garage and some retail and office areas. The tower will have a total of 408 residential units, approximately 11,450 SF of office space, and 5,710 SF of retail space. H. 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 113 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) 0.82 0.82 1.43 2.25 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, and keep the flooding below the site perimeter elevation during the SFWMD 25 year - 72 hour storm. Both Biscayne Boulevard and McArthur Causeway are Florida Department of Transportation Right -of -Ways. According to Depai anent 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 stoi fii 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 and a 36-inch water main on NE 13`h Street and on North Bayshore Drive. Refer to the attached Water Atlas for additional infoiination. Domestic water and fire line connections for this project should be provided from the existing 24-inch water main on Biscayne Blvd. However, there is the possibility that MD-WASD will require a 12" water main extension along 13`h Street from Biscayne Blvd. to N. Bayshore Drive. If that is the case, then services to the new building should be constructed from the new water main. The anticipated average daily water consumption for the entire project is 83,030.50 GPD, and is calculated as shown in Table 2. IV. SANITARY SEWER MASTER PLAN • The Miami -Dade Water and Sewer Depaitinent (MD-WASD) also provides the sanitary sewer service in this area. There is an existing 72-inch sanitary interceptor and a 6-inch sewer main along Biscayne Blvd. There is also an existing 6-inch sewer main running along the north side of NE 13th Street and connects to an existing 10" main running north on N. Bayshore Drive. Refer to the attached Sewer Atlas for additional infori ration. The sanitary sewer line from this project may be connected to one of the existing manholes on the 72-inch interceptor line running along the front of the property. This project is anticipated to generate an average daily sewage flow of 83,030.50 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 4.22 hours per day. The additional 83,030.50 GPD will only increase the elapsed time by 0.06 hours to 4.28 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 i • 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/m©nth, and is calculated as shown in Table 3. Generation rates were determined from data provided by the Miami - Dade County Department of Solid Waste. • • • Rainfall Intensity Purpose Peak Runoff 2. SFWMD 25 Year Rainfall Intensity Purpose Peak Runoff 3. FDOT 100 Year - Rainfall Intensity Purpose Peak Runoff 1. Total Net Lot Area Total Drainage Area 1. Impervious 2. Pervious TABLE 1 OPUS DRAINAGE CALCULATIONS = 0.82 Acres 2.25 Acres = 100% or 2.25 Acres 0% or 0.00 Acres 2. Average Runoff Coefficient = 0.98 3. SFWMD Design Storm Infoisnation 5-Year 24-Hour Storm (Miami -Dade County W.C. 1.1) = 6.20 inches per hour Flood Protection = CIA = (0.98)(6.20)(2.25) = 13.67 cfs - 72 Hour Storm (Miami -Dade County W.C. 1.1) = 7.40 inches per hour = Perimeter Berm = CIA = (0.98)(7.40)(2.25) = 16.32 cfs 1 Hour Storm = 5.10 inches per hour = Discharge to Biscayne Blvd. = CIA = (0.98)(5.10)(2.25) = 11.25 cfs • • • FDOT Design Stofin Information Stoiiii Duration 1 Hour 2 Hour 4 Hour 8 Hour 24 Hour 72 Hour 168 Hour 240 Hour 4. Well Data Rainfall Amount (Inches) 5.1 (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 = 24 Inches 2. Assumed Well Capacity = 700 gpm/ft. of Available Head 3. Mean High Tide Elevation 1.50 ft. (taken from W.C. 20,034-A) 4. Specific Gravity Head Loss = 2.00' 5. Proposed Number of Wells = 2 5. Hydraulic Grade Line Elevations at Well Structure 5 Year DERM Stalin = (13.67 cfs) / [(700 = 7.88' NGVD m/ft head)(0.002228 cfs/gpm)(2 wells)] + (1.50 + 2.00) 2. SFWMD 25 Year - 72 Hour Storm = (16.32) / [(700 gpm)(0.002228 cfs/gpm)(2 wells)] + (1.50 + 2.00) = 8.73' NGVD 3. FDOT 100 Year - 1 Hour Storm = (11.25 cfs)/ [(700 gpm)(0.002228 cfs/gpm)(2 wells)] + (1.50 + 2.00) = 7.11' NGVD • TABLE 2 OPUS ANTICIPATED AVERAGE DAILY FLOW OF WATER AND WASTEWATER Residential Towers 408 units Retail Space 5,710 SF of retail space Office Space 11,450 SF of office space @ 200 gpd/unit @ 5 gpd/100 SF @ 10 gpd/100 SF ANTICIPATED AVERAGE DAILY FLOW WASTEWATER Average Flow _ 0.083 mgd Peak Flow 0.311 mgd NOTES: 81,600 gpd 285.5 gpd = 1,145 gpd Total = 83,030.50 gpd 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 408 units @ 1.25 cu. yds /month per unit — 510 cu. yds./month Commercial and Retail Space 5,710 SF of retail space @ 0.25 cu. yds per 100 SF /month = 14.275 cu. yds/month Commercial and Office Space 11,450 SF of office space @ 0.25 cu. yds per 100 SF /month = 28.625 cu. yds/month Total anticipated Solid Waste generation = 552.9 Cu. Yds. /month D-WASI WATER ATLAS D N A N.T.S. WASD SEWED A 6597 2 12 S 7 35 LAS 102 2" 41 0 3740 ff -- '�' �--- 5 E 3 97 § �3 85 2 F* r 8 77 CO 5f3- 86 5= r- aa J.E. 6# 13 , TERR. • N. IAMI-DADE COUNTY DEEM Pump Station No.2 Usage and Projections 4' This iL�'_.�tt an �� c_a1 dace N Stat Station Station Current Delta Project4 R Type Owner Number E (Hrs) ET (Hrs) E' (HrE Proposed Number of gallons (qpa) ; 83030 Downstream Stations OK A►SRM+ 30 0002 4.22 0.06 4.28 AC 30 CD 1002,01 0.01 1002.0 AC 30 RS 1002.03 0.01 1002.0 IN 30 RS95AP 1001..75 0.01 1001.7 IN 30 RS941/A, 1001.89 0.01 1001.8 *71'*********- **Ye**********w** ** • • ********* ***+*******1r******0