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HomeMy WebLinkAboutTab 3 - Site Utility Study• • • March 2006 AJA ON THE BAY MAJOR USE SPECIAL PERMIT SITE UTILITY STUDY PREPARED FOR Electra on the Bay, LLC. KHA Project No.: 043030000 Prepared by: KIMLEY-HORN AND ASSOCIATES, INC. 1691 MICHIGAN AVENUE, SUITE 400 MIAMI BEACH, FL 33139 Kim eyal Corr and Associates; Inca • • Site Utility Study Introduction Aja on the Bay is a proposed 35-story multi -family, high density residential tower to be located on approximately 0.45 acres at 700 NE 26th Terrace, in the City of Miami, Florida (see Site Location Map -Fig 1). The Aja on the Bay project shall consist of residential units, a pool deck, common space and associated parking. Table 1 below, depicts the details of the proposed project. Table 1 Project Summary Occupancy Floor Units Floor Area (SF) Lobby & Corridors 1 1 18,616 Apartment 2 to 35 129 155,894 Pool Deck 8 1 20,903 Parking (Gross) 1 to 7 154 121,326 I. Drainage Existing Drainage System The on -site drainage system could not be determined, due to accessibility issues. It appears that rain water sheet flows into the adjacent rights -of -way (NE 26th Terrace and NE 26th Street), Biscayne Bay, and/or percolates into the ground water table. • • • NE26THST NE 25TH ST _ NE 24TH ST NE 23R0 ST NE 22NST Figure 1: Site Location Map NE26TH ST PEE NE 25TH ST LOCA 1. RD T r . NE 22ND TE NE 22ND ST Proposed Drainage System The drainage system for the proposed development will consist of drainage wells, for pretreatment, while the remaining water will discharge offsite into Biscayne Bay, if permitable. 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. Aja on the Bay Site Utility Study Page 3 • • • Based on preliminary calculations, it is anticipated that two (2) 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 "A" Preliminary Drainage Well Calculations, which includes the basis for design. The final drainage design for the project shall be in conformance with the requirements of the Miami - Dade County Department of Environmental Resources Management (DERM) Water Control Section, Florida Department of Environmental Protection (FDEP), and other local, state and federal regulatory agencies having jurisdiction over the project. Flood Criteria: The proposed project site grade elevations will be designed to meet floodplain management criteria according to Federal, State, Miami -Dade County and City of Miami standards as follows: 1. The subject property is located in PANEL 183 of COMMUNITY -PANEL NUMBER 12025C0183 .1 of the Flood Insurance Rate Map (FIRM). According to the National Flood Insurance Program, the property is located within Flood Zone VE 11, which has an established flood plain elevation of 11.00 NGVD. 2. Miami -Dade County Flood Criteria elevation is estimated to be 5.0 ft. NGVD. This will be used to determine proposed minimum site grade elevations. 3. The average October ground water table elevation is estimated to be 2.0 ft. NGVD. This will be used as the control water elevation for stormwater management calculations (Source: Miami -Dade County Public Works Manual, Volume II - Design Standard Detail WC 2-2). 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 below. Aja on. the Bay Site Utility Study Page 4 • • • Table 3 Existing Water Mains Location Between Water Main(s) NE 26th Terrace NE 5th Avenue and Biscayne Bay 4" NE 5'h Avenue NE 26th Terrace and NE 26th Street S„ NE 26th Street NE 5th Avenue and Biscayne Bay 6" Per the MDWASD water atlas sheet provided by MDWASD, a 4-inch water main fronts the property along NE 26th Terrace, an 8-inch water main is located along NE 5th Avenue between NE 26th Terrace and NE 26th Street, and a 6-inch water main is located on NE 26th Street between NE 5th Avenue and Biscayne Bay. In accordance with Miami -Dade Water and Sewer Department (MDWASD) criteria, the installation of a new 12-inch ductile iron pipe (DIP) water main may be required along NE 26th Terrace, connecting to the existing 16-inch water main along Biscayne Boulevard, and looped through the site to connect to the existing 6-inch water main on NE 26th Street in order to upgrade the existing water main system. In addition, MDWASD may request additional fire hydrants be placed in the vicinities of the subject project. 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 would need to be purchased by the owner and installed by MDWASD officials. See Attachment "B" 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 the Miami -Dade Water and Sewer Department within the vicinity of the project. Aja on the Bay Site Utility Study Page 5 • Table 4 Existing Sanitary Sewer Mains Location Between Sanitary Sewer Main(s) NE 26th Terrace NE 5th Avenue and Biscayne Bay g„ NE 26th Street ----NE Avenue and Biscayne Bay 8" The existing 8-inch gravity sanitary sewer main along NE 26th Terrace may have sufficient capacity to accommodate the proposed development. However, this can not be verified until a downstream analysis of the existing 8-inch gravity line is completed. 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 existing 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 for reference (See Attachment B). MDWASD Pump Station #30-0002 receives the flows from these mains. As of 01/06/06, this pump station is operating at an average yearly NAPOT of 3.02 hours which is 48% of its design capacity. Therefore, a new sanitary sewer pump station or upgrades to said pump station may not be required for the proposed development. A final deteiuiination 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. Please refer to Attachment "B" for the sewer atlas and Attachment "C" for Pump Station Monthly Information. AjaontheBay Site Utility Study Page 6 • • • Table 5 Water & Sewer Flow Generation Type of Occupancy Quantity Usage rate Total Average Daily Flow (GPD) Apartment 129 units 200 GPD per unit 25,800 Total Anticipated How 25,800 IV. 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. Table 6 Solid Waste Generation Type of Occupancy Quantity Usage rate Total Solid Waste Generated (Tons/Day) Apartment 129 units 5 lbs/unit/day 0.322 Total Anticipated Solid Waste Generated 0.322 Aja on the Bay Site Utility Study Page 7 • • • Attachment A Preliminary Drainage Well Calculations AJA ON THE BAY City of Miami, Florida DRAINAGE CALCULATIONS: "FRENCH DRAIN SYSTEMS" (MASS DIAGRAM — DERM CRITERIA) • • 1. Site Data: A. Control Water Table Elevation = 2.00 NGVD (Mean High Tide elev. per MLW Bay Datum) B. County Flood Criteria Elevation = 00 NGVD (County Flood Criteria Map. see Appendix A) C. F.1.R.M. Base Flood Elevation = 11 0(i: NGVD Zone VE (Map No,12025C01833 - Appendix A) D. Average Road Crown Elevation = NIA NGVD E. Average Existing Onsite Grade Elevation = 5 00 NGVD F. Prop. Lowest Drainage Inlet Elevation = NGVD 2. Total Site Area (A) A. Impervious Areas: a) Asphalt and concrete pavement = b) Roof areas c) Paver areas (50% impervious) = Total Impervious Area (Al) = B. Pervious areas: a) Green Areas = b) Paver areas (50% pervious) = Total Pervious Area (A2) = 3. Weighted Runoff Coefficient (C): Runoff Coefficient Impervious (CI) Runoff Coefficient Pervious (C2) = C = [(Al x CI) + (A2 x C2)] / A; C x A = Total Contributing Area; 0.860 Acres (see Drainage Areas Map -Appendix B) 46 Acres Acres 88'' Acres 0.578 Acres (67%) 94 Acres 088Acres 0.282 Acres (33%) C = 0.673 C x A = 0.58 Acres 4. Time required to generate one inch of runoff (per DERM Water Control Section D-4) Rainfall Intensity (I) = 308.5 / [(48.6 x F" + t (0.5895 + F213)] Frequency (F) = years - Frequency Curve Q = CIA, V = Qt; V(1 sn.) = Qt(t in.)' to in.) = Time to generate 1 inch of runoff V(3 in.) = CIAt(i in.) 1" x A = CTAto in) ; Solving for to i,,), to iit) = 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: = 16.11 Min. 10.00 Min. = 26.11 Min. HA\043030000,„Aja on tee Bay5Site Utility Stuly+ORAVNAGE CALGSMELLS - Ala on the Bay BARN • • • 5. Cumulative Runoff (Inflow Mass Diagram) Time . CxA (acres) I (inches). Q (CFS) Accumulated Storm Runoff (CF) (Min.) (Sexy:) .. 8 480 0.578 6.405 3.70 1,778 10 600 0.578 6.166 3.57 2,140 15 900 0.578 5.641 3.26 2,937 26.11 1567 0.578 4.743 2.74 4,299 30 1800 0.578 4.493 2.60 4,678 40 2400 0.578 3.956 2.29 5,492 50 3000 0.578 3.534 2.04 6,133 60 3600 0.578 3.193 1.85 6,650 90 5400 0.578 2.477 1.43 7,736 120 7200 0.578 2.023 1.17 8,425 180 10800 0.578 1.480 0.86 9,248 6. Drainage Well Design Discharge Rate: Based on well discharge rate of 400 GPM/ft. Head No. DW-1 DW-2 LowestInle Rim Elev. (NGVD) 7.00 7.00 Oct. Watei Table.elev. (NGVD) 2.00 2.00 Headloss due to Higher SG' of Salt Water (t,) 2.2 2.2 Head Acting` on Well (ft.) 2.80 2.80 Zell Discharge. Rate (CFS) 2.50 2.50 Well Structure Storage Volume (C. 124.8 124.8 Well Discharge Rate (CFS) 7. Detention Time: 4.99 Total Storage (CF) The drainage well structure must be designed to detain runoff for a minimum of 90 seconds prior to discharge. Qd = Design Runoff Rate (CFS) = Vd = Detention Volume (CF) = Qd x 90 sec. Vd1 = Detention Volume Per Well (CF) = W = Width of Well Structure (ft.) = L = Length of Well Structure (ft.) = 2.74 CFS 246.91 CF 123.46 CF 4.0 ft. 8.0 ft. 249.60 Hm,n is the minimum depth required from the top of well casing to the floor of the well box to achieve 90 second detention time: Hm=n. (ft.) = Vd1 I ( W x L) = 3.90 ft. Top of Well Casing Elev. = 2.50 ft. Elevation at Floor of Well Box (NGVD) = Top of Well Casing Elev. - H,,, = -1.40 ;✓:\043033O09_Aja on the E3aytSAe Utility Si,xiy1e'hAINAGE CALCStW ELLS . Aja on the Ray WELLS • • 8. Excess storm water runoff excluding well structure storage: Time Well Discharge Rate (CFS) Accumulated Well Discharge Volume (CF) . Accumulated Storm Runoff (CF) Total Overflow Volume (OF) (Min.) (Sec) 8 480 4.99 2,396 1,778 -618 10 600 4.99 2,995 2,140 -855 15 900 4.99 4,492 2,937 -1,555 26.11 1,566.87 4.99 7,820 4,299 -3,522 30 1800 4,99 8,984 4,678 -4,306 40 2400 4.99 11,979 5,492 -6,486 50 3000 4.99 14,973 6,133 -8,841 60 3600 4.99 17,968 6,650 -11,318 90 5400 4.99 26,952 7,736 -19,216 120 7200 4.99 35,936 8,425 -27,511 180 10800 4.99 53,904 9,248 -44,656 9. Excess storm water runoff including well structure storage: (Min.). Accu Storm Runoff (CF) Storage in. Well Structure (CF) Accumulated: ell Discharge Volume (CF) Total Overflow Volume (CF) 8 10 15 26.11 30 40 50 60 90 120 180 480 600 900 1,566.87 1800 2400 3000 3600 5400 7200 10800 1,778 2,140 2,937 4,299 4,678 5,492 6,133 6,650 7,736 8,425 9,248 250 250 250 250 250 250 250 250 250 250 250 2,396 2,995 4,492 7,820 8,984 11,979 14,973 17,968 26,952 35,936 53,904 -867.13 -1,104.28 -1,805.00 -3,771.31 -4,555.60 -6,736.05 -9,090.28 -11,568.00 -19,465.11 -27,760.56 -44,905,44 Safety Factor .82% Safety Factor 1.93% ,A43030000 Aja on the BaY,Site Urir y 51.PDRAENAGE CALCS\W ELLS fya on the Bay WEtLS • Attachment B MDWASD Water and Sewer Atlas • • \i\f b+.0,- /Ma5 • • E-12 • ewer liflos • • /17 a, 192 11581 1 1 12534 1 i 2538 ' 1 547 1 1 1 24' - 1.10P own._ 176;177 137 77, 7 i13 ,144 12012v 1 • [ 17311'.__. r NE l 76 172 171 i iF (5371 'v" �R 75 ,' 13 /I 1 t 5371 f \ 15 f! 1 14 7441 152 9 ,'167 NE 2i ST 166 10" < • 150 11568 j i 59 1 1. 48 154.8 fy HCIP IWEA 146 1147 -\,—•- _Z4 1 -i33 135 134 106 107 r0, 2 280 1 11241 1 Pa 97 • .32 129 \ . ._ 1......__-._ 1 154.1 15 ; ., t "1 • Li Q9 111 ..: _ ,- - 1 5 15__rt 3 1 _ 12 6 1__ L 1 _- 11361 18a 15 133 , - > 131 J Y' 130 12 Z :HOP: Eve. 7 4.2_ 111545 .j I 113 ,....(_____._ 7441 I 196 9 5371 ? — 11 F 25 ST 92 1 1S1 • 1549 1 tiF 9 TFRI2_ /128 12.fi.� ` ._ 123'1• 1 �v 1 1:44 1_549. I 1 7 ; 1 ) .1 9 y 1,20 121 122 o Attachment C Pump Station Monthly Information • • • • Pump Station Monthly intotmation: Pomp Station: ao-Gatz AttasPono, Mmototiaa DP,A 'MATZ R SEER DE FMTNIEW Ur Arkh'": Soction-Totonshin &man: if_ - F53 - Geour7,73:TII fr...T Et .-locit T91.: FA1T Spoott FT-73 P FT3 Numbeto Pumps: 5 Yearly Mani Ihrs): 3.02 2.51U,48 Fhoi Monet 4.6 hot Cap, 48 st.r. 5rnUc...packAtx4 57,5U5U5" Station liedantionFoclot StnNotCettCtaMignd) Stn Mot CapatitM614 34,560030 Intkatod Flow4a4 4,348.030 • pRjrjA • 1, 15 • ••• . • .• : • • •• • • • •T5A00611 141:01,APOT AvgDadr. ftdg Pump: Comments: U"e° mai2ithf, 'czzIJFA,'"jtii3K3VFrir-2z, • Attachment D Maps • • J • NE 29TH ST NE 28TH ST NE 27TH ST NE 26TH ST NE 25TH ST NE. 2ND S NE 30TH TE NE 30TH ST NE 29TH ST NE 28TH ST NE 27TH TE PROJECT NE 25TH ST LOCATION NE 2 TH ST NE 24TH ST NE 23RD ST z c•s w NE 22ND ST z NE 21 ST ST 11111 NE 23RD ST NE 22ND TE NE 22ND ST 1691 Michigan Avenue, Suite 400 Miami Beach, Florida 33139 Kim[ey-Horn and Associates, Inc. Phone: 305-673-2025 o,..��.....m.�� Fax: 305-673-4862 AJA ON THE BAY 700 NE 26TH TERRACE LOCATION MAP m IIII 0 rn •in p 1691 Michigan Avenue, Suite 400 Miami Beach, Florida 33139 Kimley-Hom and Associates, Inc. Phone: 305-673-2025 Fax: 305-673-4882 0IMP -_-IM AJA ON THE BAY F-I.R.M. FLOOD INSURANCE RATE MAP Kimsey-Hom and Associates, Inc. 1691 Michigan Avenue Suite 400 Miami Beach, Florida 33139 Phone: 305-673-2025 Fax: 305-673-4882 LEND: 2 (EsT1% NOTES: 1. ONT'OUR TERVAL i3O -RYJT (Excatsi as , d'cctiad) Z. DATUM S ME.AN SEA LEVEL, AJA ON THE BAY AVERAGE OCTOBER GROUND WATER LEVEL 1960-75 Kim le -Horn and Associates, Inc. 1691 Michigan Avenue Suite 400 Miami Beach, Florida 33139 Phone: 305-673-2025 Fax: 305-673-4882 AJA ON THE BAY FLOOD CRITERIA MAP