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HomeMy WebLinkAboutArticle III. Tab 4 Site Utility Study• September 2006 Columbus Centre MAJOR USE SPECIAL PERMIT SITE UTILITY STUDY PREPARED FOR 1450 South Miami, LLC KHA Project No.: 043061000 Prepared by: KIMLEY-HORN AND ASSOCIATES, INC. 1691 MICHIGAN AVENUE, SUITE 400 MIAMI BEACH, FL 33139 cowl Kimley-Horn ® ... and Associates; Inc, • • September 2006 Colu us Centre MAJOR USE SPECIAL PFRMIT SITE UTILITY STUDY PREPARED FOR 1450 South Miami, LLC KHA Project No.: 043061000 Prepared by: KIMLEY-HORN AND ASSOCIATES, INC. 1691 MICHIGAN AVENUE, SUITE 400 MIAMI BEACH. FL 33139 • • Site: Unity Study 1ntroduct u '.l'he Columbus Centre is a proposed 56-story multi -family, high density residential tower to be located on approximately _902 acre at the NW corner of South Miami Avenue and S.W. 15t Road, in the City of Miami, Florida (see Site Location Map -Fig 1). The Columbus Centre is to include one (1) tower with a common upper -level amenity -deck and ground -floor streetscape and a 596 space parking garage. Table 1 below, depicts the details of the proposed project. Table 1 Project Summary Condo 30-56 219 312,540 Hotel 19-27 234 180,689 Offices 1-18 209,376 Retail 8,584 Parking (Gross LL 1, LL2, 2 to 11 596 spaces I. Drainage Existing Drainage System The survey of existing conditions provided by Biscayne Engineering Company, L.L.C. shows an existing drainage system located on the north east portion of the site, within parcel "A." This system may not be adequately designed to treat and retain the additional flows from the other portions of the site. Therefore, a new stormwater management system will be constructed to retain the runoff generated by the proposed development. • Figure 1: Site Location Map Proposed Drainage System The drainage system for the proposed development will consist of drainage wells and exfiltration trenches to facilitate on -site disposal of storm water runoff. The 5-year, 24- hour design storm event will be used to design the stoat': water management system, in accordance with Section D-4, "Water Control", of Part 2 of the Miami -Dade County Public Works Manual. No direct or indirect drainage connections or discharge of storm runoff frorn the property to adjacent properties or rights -of -way will be permitted. 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 Columbus Centre Site Utility Study Page 3 • • • generated by the proposed development. Preliminary drainage computations for the project areas are provided in Attachment ''B„ Preliminary Drainage Well Calculations, which includes We 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. 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 191 of COMMUNITY -PANEL NUMBER 12025C0191 J of the Flood Insurance Rate Map (FIRM). According to the National Flood Insurance Program, the property is located within Flood Zone X, areas determined to be outside of the 500 year flood plain. 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). IL 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. Columbus Centre Site Utility Study Page 4 • • • Table 3 Existing Water Mains . oeation . Between --� ��'ater° Main(s) S W. 14th Terrace S.W. Ise Ave. and S Miami Ave. 8" S. Miami Avenue S.W. 14t Terrace and S.W. 15th Road " 16" S.W. I5th Road S.W. 1s` Ave. and S Miami Ave. 12" S.W. 15S Court S.W. 15th Rd. and S.W. 14t Terrace 12" Per the MDWASD water atlas sheet (F-15) provided by MDWASD, a 6-inch and 16-inch water main fronts the property along S. Miami Avenue, an 8-inch water main is located along S.W. 14th Terrace between S.W. IS` Avenue and S. Miami Ave, a 12-inch water main is located on S.W. 15`s Road between S.W. 15` Avenue and S. Miami Avenue, and a 12 inch water main located on S.W. 1st Court between S.W. 15th Rd. and S.W. 1e Terrace. 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. Columbus Centre Site Utility Study Page 5 • • • Table 4 Existing Sanitary Sewer Mains Location 13ety♦°een.. Sanitary Sewer lYlaxn(s) 5. . 15''' Road S.W. I' Ave. and S .Nliarni Ave. I 102" Force Main S.W. 14th Terrace S.W. 1'i Ct. and S. Miami Ave. 8" Gravity S.W. i5F Court S.W. .15 Rd. and S.W. 1.4` Terrace 8" Gravity S. Miami Ave. S.W. 15`i' Rd. and S.W. 14`h Terrace 8" Gravity Any of the existing 8-inch gravity sanitary sewer mains adjacent to the proposed development 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 lines are 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 could not be attained because of the size of the force main on S.W. 15'r road is larger than 12". A official letter request to the MDWASD must be made and approval from the Department of Homeland Security must be obtained prior to obtaining this information. MDWASD Pump Station #30-0008 receives the flows from these mains. As of 07/25/06, this pump station is operating at an average yearly NAPOT of 5.58 hours which is 55.8% 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 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 "C" for Pump Station Monthly Information. Columbus Centre Site Utility Study Page b • • Table 5 Water & Sewer Flow Generation Multiple Family Residential 219 units 200 GPD per unit 43,800 Hotel 234 rooms 100 GPD per room 23,400 Oflice/Retail 173,581 sf 10 GPD/100 sf 17358 Total Anticipated Flow 84,558 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 Total Solid Waste Generated (Tuns/13ay) Multiple Family Residential 219 units 5.31 lbs/unit/day 0.581 Hotel 234 rooms 2 lb/roonn/day 0.234 Office/Retail 173,581 sf 101bs/1000 sf/day 0.868 Total Anticipated Flow 1.683 Columbus Centre Site Utility Study Page 7 110 Attachment A Preliminary Drainage Well Calculations • 110 r� CALCULATIONS: i�RALNAG�, CA�.G DRAINAGE WELLS (MASS DIAGRAM_._ .D.LR!vI CRITERIA) • Columbus Centre City of . Iis mi, Florida 1. Site Data: A. Average Control Water Elevation (NGVD) 13. County Hood Criteria Elevation (NGVD) C. F.I.R.M. Base Flood Elevation (NGVD) D. Lowest proposed inlet elevation (NGVD) 2. Total Property Area : A. Impervious Areas: a) Asphalt and concrete pavetne b) Roof areas ..- Total Impervious Area (A.) 13. Pervious areas: a) Green Areas C. Total Contributing Area ._ 3. Weighted Runoff Coefficient (C): (M-DCPW :Manual Part 2 - Section t)-sr, Design 2.00 Standard WC 2.2) 5.00 (Per County Hood ;riteria Map, see Ap.. D) N/A (Zone X, Map No. I2025C0191 2, sec Apx. D) 14.00 0.903 Acres 0.850 Acres 0.000 Acres 0.850 Acres 0.051 Acres 0.901 Acres Runoff Coefficient Impervious (C1) - 0.90 Runoff Coefficient Pervious (C2) 0.30 C - [(Al x C 1) + (A2 x C2)] / A; C - 0.866 C x A Total Contributing Area; C x A 0.78 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 t) + t (0.5895 + F-2'3)] Frequency (F) - 5 years - Frequency Curve Q = CIA, V = Qt; Vo in: - Qttt ;"), tf- 3 1- Time to generate 1 inch of runoff V(t laj - C1Attt i L) I" x A = ClAttt in.) ; Solving for to in.), to i„.) - 1" / (IC) Time to Generate one inch of run-off t(in) Time to reach the inlet (Ie.) Total Time required to Generate 1 in of runoff: - 11.56 Min. - 8.00 Min. - 19.56 Min. O-WELLS-Coumbus Centre.xts _ B?.SN . (:),trtt€mia0ve Rum )1' fin l(i , `.lass Diagram,) Min.) 10 15 19.56 () 50 60 90 120 180 (See 480 600 900 1174 1800 2400 3000 3600 5400 7200 0800 CxA (acres) 80 0.780 0.780 0.780 0.780 0.780 0.780 0.780 0.780 0. 780 0.780 (inches) )5 6.166 5641 5.235 4.493 3.9'16 3.534 3.193 2.477 2.023 1.480 lccumulated Storm Q Runoff CFS 5.00 4.81 2.887 4.40 3,961 4.08 4,793 3.51 6,310 .09 7,408 2.76 8,272 2.49 8,970 1.93 10,436 1.58 11,364 1.16 12,475 6. Drainag Well Design Discharge Rate: Based on well discharge rate of 425 GPM/ft. Hard Well No. Lowest Inlet Rim Elev. (NGV➢) Oct. Water Table elev. (NGVD) Free Board (ft) Headloss due to Higher SG. of Salt Water (ft.) Head Acting on Well (t.) Well Discharge Rate (CFS) Well Structure Dimensions Well Structure Storage Volume (CF) Width (ft.) Length (ft.) DW-1 14.00 2.00 3.50 2,20 6.30 5.97 6.0 8.0 302.4 302.4 DW-2 14.00 2.00 3.50 2.20 6.30 5.97 6.0 8.0 Well Discharge Rate (CFS) 11.93 Total Storage (CF) 604.80 7. Detention Time: 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. Vdz = Detention Volume Per Well (CE)77 W - Width of Well Structure (1'0-= 1, = Length of Well Structure (fl.) = 4.08 CFS 367.58 CF 122.53 CI' 6.0 ft, 8.0 ft. 1-1,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: Ilm,,, (ft.) = Vdl (( W x L) = 2.60 ft.=Depth from top of casing to bottom of well box • • • • 38. _,> t• sF :store f xelucl no Nell structure liar. 8 11) 15 9.56 30 40 50 60 90 120 180 (Sec.) 480 600 900 1.173.53 1801) 2400 3006 3600 5400 7200 10800 Well Discharge Rate ((TS.) 11.93 11.93 1 1_ 93 11.93 1 1.93 11.93 11.93 11.93 11.93 11.93 11.93 umtaiaDe( Well 1Jiseltarge Volume (CF) 5,.727 7,159 10.739 14,1102 21,477 28.636 35,795 42,955 64,432 85,909 128,864 Accumulated Storm Runof (CF) 2,399 2.887 3.961 4,793 6,310 7,408 8,272 8,970 10.436 1 1,364 12.475 Total Overflow Volume (CF) -3.329 -4.272 -13,777 -9,209 -I5,167 -21.228 -27.52 3 -33.985 -53,996 -74,545 -116,389 9. Excess storm water runoff including well structure storage: Time Accumulated Storm Runoff (CF) Storage in Well Structure (CF) Accumulated Well Disehaxge Volume (CF) Total Overflow Volume (CF) (Mina.) (Sec.) 8 480 2,399 605 5,727 -3.933.45 10 600 2,887 605 7,159 -4,877.26 15 900 3,961 605 10,739 -7,382.25 19.56 1,173.53 4,793 605 14,002 -9,814.29 30 1800 6,310 605 21,477 -15,771.93 40 2400 7,408 605 28,636 -21,832.73 50 3000 8.272 605 35,795 -28,127.94 60 3600 8,970 605 42,955 -34,589.75 90 5400 10,436 605 64,432 -54,600.96 120 7200 11,364 605 85,909 -75,149.49 180 10800 12,475 605 128,864 -116,993.83 Saf'et'.I)at°tur 2.92 Safety Factor 3.05 Attachment B MDWASD Water Atlas • • Attachment C Pump Station Monthly Information • • Addt€x Secni ation. 36-0008 Atlas Pane: ee wAtea >ewre e nar.;am errr tii',9961666L149E }Aaeataasum in elleci airy. 15; 277+, 932 3svnxhipflan '.. . lyu . IF 5enerhtfsx dlv Teleme9y ET dock F., 3Funitaer of 6amps_ 2 Yeady5APOT (tusl: 2.93 Res flaw[gpol 927,453 Pral0apot: 5.5(1 hrs X Cap: 55.0 Sin Gvoss Capac1fylgF l.4aa: 54 Station F9edueainn Facing 1 1 Sin Net Cap Ceetil(slx6J Sin KM Capacikyl. 7.483A50 lIndicatedFtaws 914.199 7725?25 6 2.36 -2.3S 6i23e2305 237 2.37 •' 2 4i24RS 2.93 2.93 Y 2 4/ 5/2DOS .2.444 2.49 r _.. 2 427/2 0S 1.63 1.63 Y 2 f26 2JOS 0.07 0D1 '.Y 2 Date: 81u_fAPOT Avg Daily: Mg Flg: 11 Pump: Comments: s,rlr00s j aoa ITT Save 11 eturn to Re.stdta 1. 6R011SR ............... BRODSR BRUSH 9ROCSR 6RODSR 9ROPSR • Attachment aps 1691 Michigan Avenue, Suite 400 Miami Beach, Florida 33139 Kim ley -Han and Anocklesr IncPhone: 305-673-2025 •�� Fax: 305-673-4882 COLUMBUS CENTRE 1492 SOUTH MIAMI AVE. LOCATION MAP City of Miami '-,120 ' 50 4O 1111. Kimley-Horn and Associates, Inc. PO 111141RAPOI se mown gm 1691 Michigan Avenue, Suite 400 Miami Beach, FCorida 33139 Phone: 305-673-2025 Fax: 305-673--4882 COLUMBUS CENTRE 1492 SOUTH MIAMI AVE. ARM MAP 1691 Michigan Avenue, Suite 400 Miami Beach, Florida 33139 Kimley-Hom aid Assocides,IntPhone: 305--673-2025 ipema• Fax: 305-673-4882 COLUMBUS CENTRE FLOOD CRITERIA MAP • 4. 1 3 4 Pa 24,5 2-2 v! G ;502 ; 781 0 CA G 855 ;342 COCC;r 1691 Michigan Avenue, Suite 400 Miami Beach, Florida 33139 Kimley-HOM Aniggkink Ing Phone: 305-673-2025 • mom" Fax: 305-673-4882 atb 4 <75 0 • t.FGE ND .555.1.11 -2--- iiINEO (ESTIMATED) NOTES. CONTOUR iNTER/AL 1.0 FOOT (Elvin"? as indicated) M MEAN SEA LEVEL. COLUMBUS CENTRE AVERAGE OCTOBER GROUND WATER LEVEL 1960-75