Loading...
HomeMy WebLinkAboutSite Utility Study• • • ■ October 2004 Biscayne Condos MAJOR USE SPECIAL PERMIT SITE UTILITY STUDY PREPARED FOR Borges and Associates, P.A. KHA Project No.: 042410000 Prepared by: KIMLEY HORN AND ASSOCIATES, INC. 1691 Michigan Ave. Suite 400 MIAMI BEACH, FL 33139 MI Kimley-Horn and Associates, Inc. • October 2004 Biscayne Condos MAJOR USE SPECIAL PERMIT SITE UTILITY STUDY • PREPARED FOR Borges and Associates, P.A. KHA Project No.: 042410000 Prepared by: KIMLEY-HORNAND ASSOCIATES, INC. 1691 Michigan Ave. Suite 400 MIAMI BEACH, FL 33139 • • • • Site Utility Study Introduction Biscayne Condos is a proposed mixed -use development to be located at 2751 Biscayne Blvd., in the City of Miami, Miami -Dade County, Florida (see Attachment "A" Site Location Map). Currently, two (2) residential buildings exist on the east portion of the site and a vacant lot on the west side. For the purposes of this development, all existing structures will be demolished. The Biscayne Condo project includes a residential tower with ground floor retail, constructed on a parking garage structure. It will consist of approximately 75 residential condominium apartments units, 2,500 S.F of retail and approximately 155 parking spaces. Table 1, below depicts the details of the proposed project. Table 1: Project Summary Residential 75 89,359 Office 2 5,310 Total 97,169 • • • I. Drainage Existing Drainage Based on site observations and available information, there was no visible on -site drainage system within the project limits. Proposed Drainage System The drainage system for the proposed development will consist of drainage wells and exfiltration trench, if possible, to facilitate on -site disposal of storm water runoff. The 5- year design storm event will be used to design the storm water management system, in accordance with Section D-4, "Water Control", of Part 2 of the Miami -Dade County Public Works Manual. Based on preliminary calculations, it is anticipated that two (2) 24" drainage wells will provide sufficient capacity to dispose of the design 5-year 24-hour storm water runoff generated by the proposed development. Preliminary drainage computations for the project areas are provided in Attachment "B" Preliminary Drainage Well Calculations, which includes the basis for design. The final drainage design for the project should be in conformance with the requirements of the Miami -Dade County DERM Water Control Section, Florida Department of Environmental Protection, and other local, state and federal regulatory agencies having jurisdiction over the project. II. Water Distribution System The water mains owned and operated by the Miami -Dade Water and Sewer Department (MDWASD) in the vicinity of the project are shown in the Table 3. Biscayne Condos Site Utility Study Page 3 • • • Table 3: Existing Water Mains fie.. s .�_ .�� max eG_;. E A�_..' -,?�s �.3 NE 28th Street Biscayne Blvd. and East side of property 2" Biscayne Blvd. NE 28th St. and 15 ft. Alley 16" D.I. Per the MDWASD Water Atlas Sheet, a 16-inch water main, fronts the property along Biscayne Blvd and a 2-inch water main fronts the property along NE 28th St. In accordance with Miami -Dade Water and Sewer Department (MDWASD) criteria, the developer may be required to construct a new 12-inch ductile iron (DI) water main along the frontage of the property on NE 28th St. (approx. 275'). A final determination of the points of connection and requirements will not be provided by MDWASD until a Water and Sewer Agreement is requested by the owner. Water service meters will be installed by MDWASD forces at owner's expense. Service lines for domestic water, fire sprinkler systems and irrigation could be connected to the on -site water distribution system. Water service meters would need to be purchased and installed by MDWASD forces. See Attachment "C" for a copy of the MDWASD water atlas sheet for the project area. III. Sanitary Sewer Collection System Table 4 depicts the sanitary sewer mains owned and operated by Miami -Dade Water and Sewer Department (MDWASD), within the vicinity of the project. Biscayne Condos Site Utility Study Page 4 • • • Table 4: Existing Sanitary Sewer Mains . �ocannn � been Biscayne Blvd. NE 28th St. and 15 ft. Alley 8" Gravity Main (north'/z of site) and 72 Interceptor NE 281 St. Biscayne Blvd. and East side of property 10" Gravity Main The proposed on -site sanitary sewer system for the property can be connected to the either of the existing mains abutting the property. However, connecting to the existing 10-inch mains is preferable, provided that the line has capacity to handle the existing flows plus the additional flows contributed by the proposed project. A letter of availability and further coordination with MDWASD is recommended to verify the proposed sanitary sewer service connection points and requirements for this project. MDWASD may require upgrades to the sanitary sewer system, but this can not be determined without a request for a water and sewer agreement. A copy of the MDWASD Sewer Atlas sheet has been attached (See Attachment C). The flows from the existing MDWASD sanitary sewage mains on Biscayne Blvd. and NE 28th Street are received by MDWASD Regional Pump Station #2. As of October 2004, this pump station is operating under capacity as established by the USEPA, and is not under any type of moratorium (see Attachment "D" Pump Station Monthly Information). At this time, it is not anticipated that any improvements to the regional pumping and/or transmission systems will be required to connect the proposed project. However, a final determination regarding the status of the existing transmission system and the need for possible improvements will not be made until construction plans are submitted to the Miami -Dade County DERM Wastewater Section and a Sanitary Sewage System Capacity Certification Letter is issued. Biscayne Condos Site Utility Study Page 5 • • • The flows created by this project have been determined and are shown in Table 5. Apartment Reta Office Table 5: Water & Sewer Flow Generation 75 units 200 gpd per unit 2,500 sf 5 gpd per 100sf 5,310 sf 10 gpd Total Anticipated Flow per 00sf 5,000 125 531 15,656 gpd N. Solid Waste Generation Solid waste generated by this project will be collected in standard on -site containers for refuse and recyclables. Regular pick-up service will be provided either by private hauling companies and/or by the City of Miami Solid Waste Department, who will transport the waste to Miami -Dade County's or private disposal and recycling facilities. The volumes of solid waste projected to be generated by the project are shown in Table 6. Apartment Retail Office Table 6: Solid Waste Generation 75 units 2,500 sf 5,310 sf 5lbs/unit/day 0.187 6lbs/1000 sf/day 0.007 6lbs/1000 sf/day 0.160 Total Anticipated Solid Waste Generated 0.354 Biscayne Condos Site Utility Study Page 6 4110 a • Biscayne Condos Site Utility Study Attachment A Site Location Map Page 7 • • • PROPO \E 28TH ST PROJE N 1 E o' r n �T Fl 1Cmley-Hom and Associates, Inc 420 Lincoln Rood Suite 353 Miami Beach, Florida 33139 Phone: 305-673-2025 Fax: 305-673-4a82 BISCAYNE CONDOS 2751 BISCAYNE BLVD. SITE LOCATION MAP • • • Biscayne Condo Site Utility Study Attachment B Preliminary Drainage Well Calculations Page 8 • • BISCAYNE CONDOS City of Miami, Florida 1. Site Data: A. Average October Water Table Elevation = B. County Flood Criteria Elevation = C. F.I.R.M. or FEMA Base Flood Elevation = D. Average Crown Road Elevation = E. Average Existing Onsite Grade Elevation = F. Proposed drainage inlet grate elevation = 2. Total Contributing Drainage Area (A): A. Impervious Areas: a) Asphalt and concrete pavement = b) Roof areas + 113 NE building corner = Total Impervious Area (A l) NGVD NGVD (County Flood Criteria Map, see Appendix A) NGVD NGVD NGVD 0.99 Acres Acres Acres 0.89 Acres (90%) B. Pervious areas: a) Green Areas = 1 Acres (10%) 3. Weighted Runoff Coefficient (C): Runoff Coefficient Impervious (CI) Runoff Coefficient Pervious (C2) _ C= [(Al x C1) + (A2 x C2)) / A; C= C x A= Total Contributing Area; C x A = 0.84 0.83 Acres 4. Time required to generate one inch of runoff (per DERM Water Control Section D-4) Rainfall Intensity (1) _ Frequency (F) = Q=CIA, V=Qt; V(l=(AO in.),t{1inj=Time to endix A) 308.5 / [(48.6 x F O 11) + t (0.5895 + F-313)] years - Frequency Curve generate 1 inch of runoff V(1 in.) " CIAt(I in.) 1" x A = CIAt(1 in j ; Solving for t0 in.), t(1 in.j = 1" / (IC) Time to Generate one inch of run-off t(in) Time to reach the inlet (tc.) Total Time required to generate 1 in of runoff: = 12.03 Min. = Min. = 22.03 Min. DRAINAGE WELLS BASIN • • 5. Cumulative Runoff (Inflow Mass Diagram) ' 3Ylw,� ` -8.,,. 'ems, 11 ,'i' .�` ss` ✓r }+- 3 4 ':$ ' 8 480 0.831 6.405 5.32 2,555 10 600 0.831 6.166 5.12 3,075 15 900 0.831 5.641 4.69 4,219 22.03 1322 0.831 5.038 4.19 5,534 30 1800 0.831 4.493 3.73 6,721 40 2400 0.831 3.956 3.29 7,891 50 3000 0.831 3.534 2.94 8,811 60 3600 0.831 3.193 2.65 9,553 90 5400 0.831 2.477 2.06 11,115 120 7200 0.831 2.023 1.68 12,104 180 10800 0.831 1.480 1.23 13,287 6. Drainage Well Design Discharge Rate: Based on well discharge rate of: DW-1 DW-2 9.00 9,00 2.00 2.00 1.60 1.60 GPM/ft. Head 5.40 5.40 7.22 7.22 Well Discharge Rate (CFS) 14.44 7. Detention Time: ff.g 129.6 129.6 Total Storage (CF)I 259.20 The drainage well structure must be designed to detain runoff for a minimum of 90 seconds prior to discharge. Qd = Design Runoff Rate (CFS) = 4.19 CFS Vd = Detention Volume (CF) = Qd x 90 sec. = 376.79 CF Vdl = Detention Volume Per Well (CF) = 188.39 CF W = Width of Well Structure (ft.) = 4.0 ft. L = Length of Well Structure (ft.) = 6.0 ft. H„,;„ , is the minimum depth required from the top of well casing to the floor of the well box to achieve 90 second detention time: H,,,ia. (ft) = Vdl / (W x L) = 7.90 ft. Top of Well Casing Elev. = 7.00 Elevation at Floor of Well Box (NGVD) = Top of Well Casing Elev. - H,;,, _ -0.90 • 8. Excess storm water runoff excluding well structure storage: �� �1,`A �tue � �ccuu71� ,�% 13x c aar z �.'`ell� Dcscharge Vo�luu�n "„. " umul� tarp �af ab ern? "lot ft v�9. nic �> p 8 480 14.44 6,930 2,555 -4,376 10 600 14.44 8,663 3,075 -5,589 15 900 14.44 12,995 4,219 -8,776 22.03 1,321.81 14.44 19,085 5,534 -13,551 30 1800 14.44 25,989 6,721 -19,268 40 2400 14.44 34,652 7,891 -26,762 50 3000 14.44 43,316 8,811 -34,505 60 3600 14.44 51,979 9,553 -42,425 90 5400 14.44 77,968 11,115 -66,853 120 7200 14.44 103,957 12,104 -91,853 180 10800 14.44 155,936 13,287 -142,649 9. Excess storm water runoff including well structure storage: 8 10 15 22.03 30 40 50 60 90 120 180 480 600 900 1,321.81 1800 2400 3000 3600 5400 7200 10800 2,555 3,075 4,219 5,534 6,721 7,891 8,811 9,553 11,115 12,104 13,287 259 259 259 259 259 259 259 259 259 259 259 6,930 8,663 12,995 19,085 25,989 34,652 43,316 51,979 77,968 103,957 155,936 -4,634.91 -5,847.75 -9,034.80 -13,810.34 -19,527.59 -27,020.90 -34,763.89 -42,684.31 -67,112.12 -92,112.22 -142,908.36 Safety Factor 3.45% Safety Factor 3.62% aritl�?y•�'om d Associat= ,,nc 420 Lincoln Road Suite 353 Miami Beach, Florida 33139 Phone: 305-673-2025 Fox: 305-673-4882 BISCAYNE CONDOS 2751 BISCAYNE BLVD. AVERAGE OCTOBER GROUND WATER LEVEL 1960-75 1,1 ElEn Kira ' "om and dates, Inc 420 Lincoln Road Suite 353 Miami beach, Florida 33139 Phone: 305-673-2025 Fax: 305-673-4662 BISCAYNE CONDOS 2751 BISCAYNE BLVD. F.LR.M. FLOOD INSURANCE RATE MAP r Kimley-Hom and SSE! a6iS, �l icy 420 Lincoln Road Suite 353 Miami Beach, Florida 33139 Phone: 305-673-2025 Fax: 305-673-4882 BISCAYNE CONDOS 2751 BISCAYNE BLVD. o5 a 1 FLOOD CRITERIA MAP • Attachment C Existing Utility Records • • f—, /171,. 24' 182 {1 581) 180 l 1 ■ 6" + �`_ / 6 0 \ 181A 2634 1 1 I2636 (15471 �� 1 1 151 5 612 fyO 1•t \ , AR_9 • .ill KJ • I179,177 1 17 1`1 —'1. N 29 ST • • a ----„7 58 \ 161 1 \r1 1549.' 1 125 Ni 28 TER 12+4 129 43\ M 28 ) 542 ,1.11,545,.. 1 1 , t; 15Q3 1 1 119 i ► 8,,.._ -gam')' 110., ,FIE26ST 117 15 ' r—^. 111 '—= 15377 _ (7441 �1 11 ", 86 9 , , --`�. NE 25 ST 92 ,15 fKSP &Eii / "r 09 / 113 198 f r (53712. 1 12 ,,16 T5371 11548 1 f 120 121 122 • • \f\Jtthr Hna5 6 12' .42 1B8 i 0 • • Attachment D Pump Station Monthly Information • • • • • MIAMI DADE WATER & SEWERDEPARTMENTlJ Addr.,925 BISCAYNE BLVD Sec -Township -Range 31-53--42 Genr. ET cl©ck.Y Telm.Y #Pumps. 5 Pump Type.A Stn C1ess.M Speed.R Hrspwr.+ Res flow(gpd) Plans.. 2,561,944 Plats.. 0 Extens. 0 Proj Napot 5.05 hrs 3.21 hrs 3.21 hrs Date 08/25/2004 07/27/2004 06/25/2004 05/26/2004 04/27/2004 03/29/2004 02/27/2004 Ready. Cap 50.60 32.10 32.10 Mo : NAPOT Avg Daily Flows 3.38 13.50 0.00 2.82 11.28 0.00 2.79 11.16 0.00 2.85 11.40 0.00 3.17 12.67 0.00 3.28 13.10 0.00 3.25 12.98 0.00 Signature..LEALG Moratorium.. Moratorium effective since / / Yearly NAPOT (hrs) 3. E Stn Gross Capacity(gpd).. 57,600,0C Station Reduction Factor 0.E Stn Net Cap Certif(gpd).. Stn Net Capacity(gpd).... Indicated Flows(gpd)..... 34.560,0C 4,622,4C Rgd # Comments Fig Pmp Y 5 Y 5 Y 5 Y 5 Y 5 Y 5 Y 5 Sign Date..03/17/2003 13:52:24.01 8e - 673 - r-