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HomeMy WebLinkAboutSite Utility Study• Mist Biscayne Boulevard and NE 8th Street Site Utility Study • CTE Project No. 03-0707-40 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 JULY 2003 • • • • . INTRODUCTION The proposed site is located on the block of NE 8th Street and NE 9th Street between Biscayne Boulevard and NE 2nd Avenue. The site consists of 1.72 acres (net) and it is currently an asphalted parking lot. The proposed project will include a 57-story residential tower with a 10.5-level parking garage with retail areas at levels 1 and 2, and five office levels. The tower will have a total of 516 residential units, approximately 29,300 SF of retail space, and approximately 22,500 SF of office space. II. 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 east 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) 1.75 1.75 1.70 3.45 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 1 • • • 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 stoiiii, and keep the flooding below the site perimeter elevation during the SFWMD 25 year - 72 hour storm. Biscayne Boulevard is a Florida Department of Transportation Right -of -Way, State Road Number 5. 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. The Department will require the interconnection of the existing 12-inch water main on NE 2nd Avenue with the existing 24-inch water main on Biscayne Blvd. with approximately 375 LF of a new 12-inch ductile iron water main extension. Domestic water and fire line connections for this project will be provided from the 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 106,915 GPD, and is calculated as shown in Table 2. 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 sanitary sewer mains all around the property. Refer to the attached Sewer Atlas for additional information. The existing sewer lines have sufficient invert elevation and capacity to collect the sewage flow from this project. Service to the proposed 57 story residential tower will be provided by sanitary laterals connected to the existing sewer mains at either SE 8th or SE 9th Street. This project is anticipated to generate an average daily sewage flow of 106,915 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 3.60 hours per day. The additional 106,915 GPD will only increase the elapsed time by 0.07 hours to 3.67 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 Depat tment. The solid waste will then be transported to Metro-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 773.5 Cu. Yd/month, and is calculated as shown in Table 3. Generation rates were determined from data provided by the Metro -Dade County Department of Solid Waste. 3 • • • 1. Total Net Lot Area Total Drainage Area 1. Impervious 2. Pervious TABLE 1 MIST DRAINAGE CALCULATIONS = 1.75 Acres = 3.45 Acres 100% or 3.45 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 Purpose Peak Runoff 2. SFWMD 25 Year Rainfall Intensity Purpose Peak Runoff 3. FDOT 100 Year - Rainfall Intensity Purpose Peak Runoff = 6.20 inches per hour = Flood Protection = CIA=(0.98)(6.20)(3.45) = 20.96 efs - 72 Hour Storm (Miami -Dade County W.C. 1.1) = 7.40 inches per hour = Perimeter Beuu = CIA--(0.98)(7.40)(3.45) = 25.02 cfs 1 Hour Storm = 5.10 inches per hour = Discharge to Biscayne Blvd. = CIA=(0.98)(5.10)(3.45) = 17.24 cfs 4 • • • 4. FDOT Design Storm Information Storm Duration 1 Hour 2 Hour 4 Hour 8 Hour 24 Hour 72 Hour 168 Hour 240 Hour 5. 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 = 800 gpmlft. 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 = 3 6. Hydraulic Grade Line Elevations at Well Structure 1. 5 Year DERM Storm = (20.96 cfs)/[(800 gpm/ft head)(0.002228 cfs/gpm)(3 wells)] + (1.50 + 2.00) = 7.42' NGVD 2. SFWMD 25 Year - 72 Hour Storm (25.02)[(800 gpm)(0.002228 cfs/gpm)(3 wells)] + (1.50 + 2.00) = 8.18' NGVD 3. FDOT 100 Year - 1 Hour Storm = (17.24 cfs)[(800 gpm)(0.002228 cfs/gpm)(3 wells)] + (1.50 + 2.00) = 6.72' NGV❑ 5 • • • Consul -Tech Development Services, Inc. MIST Made by: H.D. Date: 7; I6/2003 Checked by: MAO Time: 5:00 PM The runoff produced by the project will be disposed of by three (3) proposed 24" drainage wells. Total Drainage Area = 3.45 acres. Impervious Area = 3.45 acres. Pervious Area = 0.00 acres. Lowest Structure Top Elevation = 8.00 ft. NGVD. (C= 0.95 ) (C = 0.25 ) Mean High Tide Elevation = 1.50 ft. NGVD. Specific Gravity Head Loss = 2.00 ft. Well Capacity = 800 gpm / ft. of available head (24" dia. Well) Number of Drainage Wells = 3 Design Storni Frequency = 5 Years Minimum Time of Concentration = 10.00 Minutes Inflow Rate Towards Well = CIA Hydraulic Head at Well = Inflow rate / (Well Capacity x Number of Wells) HGL Elevation at Well = Hydraulic Head + Mean High Tide Elev. + Specific Gravity Head Loss Minimum Time of Concentration = 10.00 Minutes CA = 3.2775 Rainfall Intensity = 6.10 in/hr Inflow Rate Towards Well = 19.99 cfs Hydraulic Head at Well = 3.74 The maximum stage of 7.24' does NOT exceed the lowest rim elevation of 8.00'. • • • TABLE 2 MIST ANTICIPATED AVERAGE DAILY FLOW OF WATER AND WASTEWATER Residential Towers 516 units Retail Space 29,300 SF of retail space Office Space 22,500 SF of retail space @ 200 gpd/unit @ 5 gpd!100 SF @10gpoll00SF ANTICIPATED AVERAGE DAILY FLOW WASTEWATER Average Flow = 0.107 mgd Peak Flow — 0.401 mgd NOTES: = 103,200 = 1,465 gpd = 2,250 gpd Total = 1.06,915 gpd 1. Peak flow uses a factor of 3.75 times average flow (Recommended Standards for Wastewater Facilities, 1990 Edition) 2. gpd Y gallons per day 3. No industrial wastewater is anticipated to be generated 4. mgd = million gallons per day 6 • • TABLE 3 MIST SOLID WASTE GENERATION Residential Towers 516 units @ 1.25 cu. yds /month per unit = 645 cu. yds./month Commercial and Retail Space 29,300 SF of retail space @ 0.25 cu. yds per 100 SF /month = 73.25 cu. yds/month Commercial and Office Space 22,500 SF of retail space @ 0.25 cu. yds per 100 SF /month = 55.25 cu. yds/month Total anticipated Solid Waste generation = 773.5 Cu. Yds. /month 7 • D-WASJJ WATE 3 N.T.S. AT AS 3 NE w NE 3 7'{ /2 0 I *40 • 8 cn /! N f -ofr Ty 78 N.E, 9219 52 3246 6 �4. 921 2 373 in T. i 3 7 8 FJ 400 92 tZ 9 2 19 6 V 9-WASD S N N.T.S. • - W_ATLAS • MIAMI-DADE COUNTY DERM Pump Station No.2 Usage and Projections • • 16. 1't,. , 1 ..A,' Pump Station 5Cation,,30 -0002 Atlas Pg..E13 MIA MI DADE -RATER a SEWER DEPARTMENT Addr..S25 BISCAYNE BLVD Sec -Township -Range 31-53-42 Gene._ ET clock , Y TeJ. Y #Pumps . 5 Pump T;:rpeA Stn iass.M Speea.R Erspwr.+ Res flow(gpd) Plans.. 1,212,119 Plats.. 0 Extens. 0 Proj Napet 3.60 hrs 2.76 hrs 2.76 hrs Cap 36.00 27.60 27.60 Date MQ.NAPOT 05/27/2003 04/25/2003 03/27/2003 02/26/2003 01/27/2001 1.2/23/2002 11/21/2002 GOLD/M GOLD/D GOLD/G • • Station <D›owns Codes & Monthly Information 93 Review› Mcratcri lei.. 0R Moratorium eective since / 1 Yearly NAPOT (h s) 2.76 Stn Gross Capacity (qpd) .. 57, 600, 000 Statton.Reduction Factor...—. 0.60 Stn Net Cap Certif(gpd)., 0 Stn Net Capacitv(gpd) „ .. 34,560,000 Indicated F1ows(grad)..... 3,974,400 Avg Daily Flows Rgd # 1.40 5.61. 0.72 2.87 2.77 11.04 2.78 11.13 Fig Prnp 0.00 Y 5 0.00 Y s 0.00 Y 5 0.00 Y 5 2.80 1 .21 0.00 Y 3.03 12.13 O.bo Y 5 2.99 11.9i 0.00 Y 5 Signature..LEALG I<m>pravernent GOLD/S tream Station Cata<g>ories GOLD/T Comments Sign Date <S>tation Inform. Sewer Cer<t>ifica ..03/17/2003 13:52:24.01 GOLD/U <U>pstrean Station GOLD/P <P>uttp Ir_forrr.atian tion �_. 16.23:3 1': 4A l�f L -n =2003071611531801*SILV�,.' * This is no.. �.. off'. a1 chop._. 'nt * CurreriC Delta='o; e^ted . Stat station Station ET (Hrs) FT (firs) (firs) R Type Owner Number ellors ( Pd) 104675 Proposed Number of 5 Downstream Stations ***********'�****,*xtx *��*�xx�Wx**��*�wa.�*�*x**x�**** .0.07 Ok ASRM+ 30 0002 1002.13366�1 0.02 IN 30 1001.99 0.01 AC IN 30 RS95APR 30 RS 1001.72 0,01 N IN 30 RS94M 1(7{?1.85 0.01 R • • ** tie**•*** 3.67 1002.15 10C2.00 1001.72 1001.56