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HomeMy WebLinkAboutTab 3 Site Utility Study• February 2006 Urbana -Mixed Used Tower MAJOR USE SPECIAL PERMIT SITE UTILITY STUDY • PREPARED FOR HAI-Group Developments, Inc. KHA Project No.: 042687000 Prepared by, KlMLEY-HORN AND ASSOCIATES, INC. 1691 MICHIGAN AVENUE. SUITE 400 MIAMI BEACH, FL 33139 • Kim ey-Horn and Associates, • • • Site Utility Study Introduction Urbanaa is a proposed mixed -use development to be located on the north-east corner of NE 2nd Avenue and NE 17th Terrace, in the City of Miami, Florida (see Site Location Map -Fig 1). The Urbana project shall consists of approximately 121,770 sf. of residential space, 9,846 sf. of retail space, and a parking garage. Table 1, below depicts the details of the proposed project. Table 1: Project Summary Retail 9,846 Residential 100 121,770 Total 100 131,616 Parking (Gross) 592 Spaces I. Drainage Existing Drainage There is a one existing drainage inlet visible within the property and this inlet most likely connects to an onsite drainage system. Construction of the proposed development will require that the existing storm water management system be demolished. Urbana Site Utility Study Page 2 • • • Figure 1: Site Location Map PROPOSED PROJECT T 7l I 6TH1ST ZE NE Proposed Drainage System 16i-,H 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 six (6) 24" drainage wells will provide sufficient capacity to dispose of the design 5-year 24-hour storm water runoff generated by the Urbana Site Utility Study Page 3 • • • 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 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 is shown in the Table 3. Table 3: Existing Water Mains ()cation BetM'een Water 'Main:(s): NE 17t Terrace NE 2nd Avenue and NE 2nd Court 2" NE 2nd Avenue NE 17th Terrace and NE 18th Street 6" and 20" NE 2nd Court NE 17th Terrace and NE 18th Street 4„ Per the MDWASD Water Atlas Sheet, 20" and 6" water mains are located along NE 2nd Avenue. 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 connecting the existing 20" water main along the frontage of the property on NE 17th Terrace. A final determination of the points of connection and requirements will not be provided by MDWASD until Water and Sewer Agreement is requested by the owner. Water service meters will be installed by MDWASD forces at owner's expense. Water service meters would need to be purchased at the owner' s expense and installed by MDWASD forces. See Attachment "B" for a copy of the MDWASD water atlas sheet for the project area. Urbana Site Utility Study Page 4 • 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. Table 4: Existing Sanitary Sewer Mains NE 17th Terrace 8" Gravity Line NE 2nd Avenue 16" FM Sludge Line and 8" Gravity Main On -site 6" and 8" Gravity Lines Per the MDWASD Water Atlas Sheet, 6" and 8" sanitary sewer lines are in conflict with the proposed improvements. Said lines will need to be removed prior to construction of the proposed development. There is a possibility the 10" gravity line along NE 2zad Ct. will need to be extended to NE 17th Terr. along the frontage of the property. However, this can not be verified until a downstream analysis of the existing sanitary sewer system 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 other 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 B). MDWASD Pump Station #2 receives the flows from these mains. AS of 01/06/06, this pump station is operating at an average yearly NAPOT hours of 3.02 which is 48% of its design capacity. Therefore, a new sanitary sewer pump station or upgrades to said pump station are not anticipated for the proposed development. 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. Please refer to Attachment `B" for the sewer atlas and Attachment "C" for Pump Station Monthly Information. Urbana Site Utility Study Page 5 • • • Table 5: Water & Sewer Flow Generation Type o Occupancy:. Apartment 100 units 200 gpd per unit Average Daily Flow; (gpd) 20,000 Retail 9,846 sf 5 gpd per 100sf 493 Total Anticipated Flow 20,493 gpd 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. Urbana Site Utility Study Table 6: Solid Waste Generation Type of Occupancy Apartment Phase l Quantity 100 units 5 lbs/unitlday Total. Solid Waste Generated (Tons/Day) 0.250 Retail 9,846 sf 6 lbs/1000 sf/day 0.030 Total Anticipated Solid Waste Generated 0.280 Page 6 • • Attachment A Pre nary Drainage Well Calculations URBANA City of Miami, Horida RAINAGE CALCULATIONS: DRAINAGE WELLS (MASS DIAGRAM — DERM CRITERIA) • • 1. Site Data: A. Average Control Water Elevation (NGVD) 13. County Flood Criteria Elevation (NGVD) C. F.1.R.M. Base Flood Elevation (NGVD) = D. Adjacent Existing Road Crown Elevations: Highest (NGVD) Lowest (NGVD) _ E. Adjacent Existing Back -of -sidewalk Elevations: Highest (NGVD) = Lowest (NGVD) _ F. Lowest proposed inlet elevation (NGVD) 2. Total Property Area 2,00 5.0( " (Per County }l r t Criteria g Jap, See a_ _. 9.00 (inane AE, Map No,. i2025CoLLilJ see Apx.;) 9.7 (NE2ad Avenue 6.4 (NEj2nd CO 1.330 Acres A. Impervious Areas: a) Asphalt and concrete pavement = 0.260Acres b) Roof areas = 1.000 Acres c) 1f3 of the NE building corner = 158 i', Acres (in excess of property area) Total Impervious Area (A) = 2.840 Acres B. Pervious areas; a) Green Areas = C. Total Contributing Area = 3. Weighted Runoff Coefficient (C): Runoff Coefficient Impervious (C1) = Runoff Coefficient Pervious (C2) = 0,30 C = ((Al x C1) + (A2 x C2)j 1 A; C = 0.886 C x A = Total Contributing Area; C x A = 2.58 Acres 0.070 Acres 2,910' 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""tt) + t (0.5895 + F2J3)1 Frequency (F) = years - Frequency Curve Q = CIA. V = Qt; V(i ;n) = Qt(t ), tEt )= Time to generate I inch of runoff Vt,,„.)=ClAto 1" x A = ClAto s) ; Solving for to ;„), t,, i„) = 1" / (IC) Time to Generate one inch of run-off t(in) Time to reach the inlet (le.) Total Time required to generate 1 in of runoff: = 11.24 Min. 10.00 Min.. = 21.24 Min. DWELLS }s BASIN • • • 5. Cumulative Runoff (Info Mass Diagram) Time CxA (acres) 1 (inches) Q (CFS) Accumulated Storm Runoff (CF) (Min.) (Sec.) 8 480 2.577 6.405 16.51 7.923 10 600 2.577 6.166 15.89 9.534 35 900 2.577 5.641 14.54 13,084 21.24 1274 2.577 5.099 13.14 16,747 30 1800 2.577 4.493 11.58 20,842 40 2400 2.577 3.956 10,20 24,470 50 3000 2.577 3.534 9.11 27,323 60 3600 2.577 3.193 8.23 29,626 90 5400 2.577 2.477 6.38 34,469 120 7200 2.577 2.023 5.21 37,536 180 10800 2.577 1..480 3.82 41,203 6. Drainage Weil Design Discharge Rate: Based on well discharge rate of: 700 GPM/ft. head No.: DW-1 oldest hale Rim Elev. (NGGVD) 7.00 Oct. Water Table elev. (NGVI)) 2.00 Fleadloss due to Higher SG of Salt Water (ft.) 2.20 ead Acting. on Well (ft.) 2.80 Well Discharge Rate (CFS) 4.37 Well Structuie Dirtiertsions Width: (ft:) 6 en 2si at.) DW-2 7.00 2.00 2.20 2.80 4.37 0 DW-3 7.00 2.00 2.20 2.80 4.37 6' 0 DW-4 7.00 2.00 2.20 2.80 4.37 6'. 0! DW-5- 7.00 2.00 2,20 2.80 4.37 2: DW-6 7.00 2.00 2.20 2.80 4.37 2. Well Structure Storage Volumi (CF) 201.6 201.6 201.6 201.6 201.6 201.6 Well Discharge Rate (CFS) 7. Detention Time: 21.84 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. = VdDetention Volume Per Well (CF) = W = Width of Well Structure (ft.) = L = Length of Well Structure (ft.) = 13.14 CFS 1182.63 CF 197.11 CF 6.0 ft. 12.0 ft. 1008.00 Hm;,, is the minimum depth required from the top of well casing to the floor of the well box to achieve 90 second detention time: (ft.)=Va l(WxL)= 2.80 ft.=Depth from top of casing to bottom of well box • • • 8. Excess storm water runoff excluding well structure storage. Time Well Discharge Rate (CFS) Accumulated Well Discharge Volume (CF) Accumulated Steno Runoff (CF) Total Overflow Volume (CF) . (Min.) (Sec) 8 480 21.84 10,481 7,923 -2,559 10 600 21.84 3,102 9,534 -3,567 15 900 21.84 19,652 13,084 -6.569 21.24 1,274.49 21.84 27.830 16,747 -11,083 30 1800 21.84 39,305 20,842 -18,463 40 2400 21.84 52.406 24,470 -27,937 50 3000 21.84 65,508 27,323 -38,185 60 3600 21.84 78,610 29,626 -48,983 90 5400 21.84 117,914 34,469 -83,446 120 7200 21.84 157,219 37,536 -119,683 180 10800 21.84 235,829 41,203 -194,626 9. Excess storm water runoff including well structure storage: Time Accumulated Storm Runoff (CF) . Storage in Well Structure (CF) Accumulated Well .. Discharge Volume (CF) :.. Total Overflow Volume (CF) (Mira.) (Sec) 8 480 7,923 1,008 10,481 -3,566.72 10 600 9,534 1,008 13,102 -4,575.17 15 900 13,084 1,008 19,652 -7,576.78 21.24 1,274.49 16,747 1,008 27,830 -12,090.52 30 1800 20,842 1,008 39,305 -19,470.68 40 2400 24,470 1,008 52,406 -28,944.69 50 3000 27,323 1,008 65,508 -39,192.93 60 3600 29,626 1,008 78,610 -49,991.43 90 5400 34,469 1,008 117,914 -84,453.91 120 7200 37,536 1,008 157,219 -120,691.13 180 10800 41,203 1.008 235,829 -195,633.80 Safety Factor 1.66% Safety Factor 1.72% Attachment B Existing Utility Records • • NE 18 ST f 6" l OVER NE 17 TER 2" =BISCAYNE 1 PLAZA DW2003-21 1 321 #TLAs (fE-13 ekti Lii ST` 174 iE18ST 179A NE 17 TER 202 5 1 1084 Jai 1 10 1 �J 1084 I 76 201 1D1 170 9 • Attachment C Pump Station Monthly Information • • • Pump Steam 144mOlp InfoImatiocc Pump Stigia*, 30-0007 An. Pep, MVQ4I IVWE WATEA,SONER DEPFATI4ENT TTW t a Nowa c4i.0 54Ktiao-Torimhip-P.rgr. Fl.; • - crutratoe Telcmeiry fr. ET dark ft:A Typc: F:1* P Ninth. of Napa, 5 YtArly NAPO NO. 3 0,2 2.5/4.2a3 Ploi kaput 4.11 tva t C - 4R ....C-.AP.lat71914 5.-6MM Sta6an Racludion Factx .6 Sto N SIntilelCagracily(pl 34.56011X1 IndcaiedrIvonfliA 4348.330 10/26/2005;'3.95 15.e0 Of :5 14106-6-4- EITX:2605 ,2 BO 1.13Y 1?fit,,11: 1AODS on, hs. • Cammat., 14.14APOT Avg Datly: 1 - - • Attachment D Maps • • 7 Kimley-Horn and Associates, Inc. 1691 Michigan Avenue Suite 400 Miami Beau, Florida 331.39 Phone- 305-673-2025 Fa 305-673-4882 URBANA FLOOD CRITERIA MAP Kimsey -Horn and Associates, Inc. 1691 Michigan Avenue Suite 400 Miami Beech, Florida 33139 Phone: .305--673-2025 Fox: 305-673-4882 4�6Y�`Fi '�1K �- 2- (E.ST1AdAtTED) I. CON OU 4NTEPVAL 1 ?FOOT (Excsopt opt tndid) a E. SEA LEVEL. U RBANA AVERAGE OCTOBER GROUND WATER LEVEL 1960-75 APPRONIMATE scx_E so° 0 500 FEE NATIONAL rLooD INSURANCE PROGRAmL\ FIRM FLOOD INSURANCE RATE MAP DADE COUNTY, FLORIDA AND INCORPORATED AREAS PANEL 183 OF 625 (sEEOEx re PANELS NUT PHNSEDi Evc 0:mti. ad: 1:11,1N1:1: %NO PANEL SU; .1. Foer41 Ent,rte,7 MAP NUMBER 12075C0193 MAP REVISED V.APCH 2, 1994 i• se ...lel copy af patter, el We atewe referenced.... rneo. wet extrected utAng F.MJT OreL-no. Thie rn, dcee nca robed chenges or ernenderterne N.hich n haw been mode suleeequont the dale on the RE* block. For the West proclkict Enbtrrrialorl atoutNretimet Flood Inelliance PPoyeern nktfl,rM Flood fAer, Store PI WOO, PT! • feme.oe • •