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HomeMy WebLinkAboutSite Utility Study• • • Infinity II Site Utility Study Infinity II MAJOR USE, SPECIAL PERMIT SITE UTILITY STUDY PREPARED FOR Colonial Development Group, L.L.C. by: KIMLEY-HORN AND ASSOCIATES, INC. 8603 S. DIXIE HIGHWAY - SUITE 411 MIAMI, FL 33143 DECEMBER 2004 Page 1 • • Infinity II Site Utility Study Introduction The Infinity II is a proposed 66 story mixed -use high rise building to be located on a 1.30 +/- acre property on the west side of South Miami Avenue between Southwest 13th Street and Southwest 14th Street, in the City of Miami, Miami -Dade County, Florida (see site location map -Fig 1). Currently, a two story office building of 15,500 sf exists on the southwest corner of the subject property and a single family home of 4,500 sf adjacent to the office building. For the purposes of this development, all existing structures will be demolished. The Infinity II development consists of a total of 527 residential apartments units, 52,300 sf of office space, 18,806 sf of storage space, and approximately 704 parking spaces. Table 1, below depicts the phase details of the proposed project. Table 1: Project Summary Residential . Office Storsage paring, fs� 527 52,300 18,806 704 Infinity 11 Site Utility Study Page 2 • • Infinity II Site Utility Study Figured.: Site Location Map Page 3 • I. Drainage Relative to the above -referenced project, the following information should be used during the storm water management design and site grading. Flood Criteria: The proposed project site grade elevations will be designed to meet flood criteria according to Federal State, Miami -Dade County and City of Miami standards as follows: 1 The subject project is located in PANEL 191 of COMMUNITY -PANEL NUMBER 12025C0191 J of the Flood Insurance Rate Map (FIRM), provided in Attachment "A". According to the National Flood Insurance Program, the project is in Zone XJD, for which a base flood elevation has not been determined. The closest base flood elevation of 11.0 ft NGVD will be used for the proposed Finish Floor Elevations. 2. Miami -Dade County Flood Criteria elevation as per Amended Plat of Flood Criteria Map, plat book 120, page 13 is estimated to be 5.0 ft. NGVD. This will be used to determine proposed site grading minimum grade elevations. A copy of this map is provided in Attachment "A". 3. The average October ground water level elevation is estimated to be 2.0 ft. NGVD. This elevation will be used to compute drainage well capacity and roadway base clearance. (Source: Dade County Department of Environmental Resource Management & Miami - Dade County Public Works Manual, Volume 11 - Design Standard Detail WC 2-2). Attachment "A" provides a copy of the "Average October Ground Water Level Map". Existing Drainage Presently, the site is partially developed. There are four existing drainage inlets visible within the property boundaries to serve the existing office building. These inlets most likely connect to an onsite drainage system consisting of either drainage wells and/or French drain. Construction of the proposed development will require that the existing storm water management system be demolished. 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 three (3) 24" drainage wells will provide sufficient capacity to dispose of the design 5-year, 24-hour storm runoff contributed 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 confot mance 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 public water distribution system that would serve the project is owned and operated by the Miami -Dade Water and Sewer Department (MDWASD). Existing water mains in the vicinity of the project are shown below in the Table 3. S.W. 13th ST. S.W. 13t'' ST. Table 3: Existing Water Mains S. Miami Ave. and S.W. 151 Ave. Approx. 200 I.F from S. Miami Ave. Water Mairi(s). Diameter (in) 4"D.I. 12" D.I. S.W. 14`r ST. S. Miami Ave. and S.W. ls` Ave. 6" D.I. S. Miami Ave. S.W. 14th St. and S.W. 13th St. 6" D.I. S. Miami Ave. S.W. 14t'' St. and S.W. 13th St. 16" D.I. Per the MDWASD Water Atlas, an existing 12-inch water main, which has not yet been conveyed to MDWASD, fronts the property along S.W. 13t'' Street. There is also a 16- Infinity II Site Utility Study Page 5 • • inch water main along S. Miami 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 along the frontage of the property on SW 14t St. 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 from the existing water distribution system. A copy of the MDWASD water atlas sheet for the project area has been attached. 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 ......................................... Lacatt#n S.W. 13t ST. S. Miami Ave. and S.W. r Ave. 20" D.I. Force Main 8" Gravity S.W. 14`h ST S. Miami Ave. and S.W. r Ave. 8" Gravity S. Miami Ave. SW 13th St. and SW 14th St. 8" Gravity A copy of the MDWASD Sewer Atlas sheet has been attached. The proposed on -site sanitary sewer system for the property may be connected to either of the existing public gravity mains abutting the property provided there is sufficient depth and flow capacity in the system. A letter of availability and further coordination with MDWASD is recommended to verify proposed sanitary sewer service connection points and requirements for this project. Infinity 11 Site Utility Study Page 6 • The flows from the existing MDWASD sanitary sewage mains on South Miami Avenue, SW 13th and 14th Streets are received by MDWASD Regional Pump Station #1, which is located at 390 NW North River Drive. Pump Station No. 1 is currently operating at an average yearly NAPOT of 4.88 hours/day, approximately 50% of the maximum allowed by EPA, and is presently not under any type of moratorium (see attached pump station report). 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. The additional sewage flows anticipated for this project have been determined and are shown in Table 5. Table 5: Water & Sewer Flow Generation Apartment 527 units 200 gpd per unit Total Average Daily Fl©w (gp), 105,400 Office 52.300 sf 10 gpd per 100sf 5,230 Total Anticipated Flow 110,630 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. Infinity 11 Site Utility Study Page 7 • • Infinity II Site Utility Study Table 6: Solid Waste Generation Type of Occupancy: Apartment 527 units 5lbs/unit/day Total Solid. Waste Generated (Tonsil)ay) 1.32 Office 52,300 sf 6lbs/1000 sf/day .16 Total Anticipated Solid Waste Generated 1.48 Page 8 • Attachment A Maps • • • • •1 c#164 1dei • es: PROJECT LOCATION (AVERAGE OC''. W.T. ELEVATION = 2.0') LEGEND' 2 {ESTIMATED} CONTOUR INTERVAL 1.0 FOOT (Except as indicated) 2. DATUM IS MEAN SEA LEVEL. pri am in IGmley-Horn and Associates, Inc. 8603 South Dixie Hwy Suite 411 Miami, Florida 33143 Phone: 305-662.6445 Fax: 305-662.6492 INFINITY II KHA Proj. No. 042339001 AVERAGE OCTOBER GROUND WATER LEVEL 1960-75 544 4Q PROJECT LOCATION (MDC FLOOD CRITERIA ELEVATION = 5.0) 6 LEGEND EX,s TINE EANAL ==:r ROROSED CANAL f C O. WATER CONTROL STRUCTURE OAP[ CO. WATER CONr.OI STRUC TORE FLOOD CRITERIA CONTOURS EVEN-FDOT INTERVAL NAtf -fool IN?ERVIL -�SNTERNEDIATE INTERVAL 0 sx0ER$ xzy E O SL 54-42 NOTE YINSNUM ELEVATION OF SO ET AP0LIES TO ALL AREAS Er CERT •NE RE INDICATED OTNE RwISE. FOR AREAS WEST OF EDE*OLADES NATOOH*L R*RR AND WEST Of CONSERVATION ARE* FLOOD CR0TER1A IS TENTATIvETT ESTAALISNED AT 10.0 fT. �2 11,11N [LEV OF SEA•*L1S FOR W*VE RROTECTION NOT SNO*N. 3. ELEVATIONS w.S.L NATIONAL 1125 DATE.. K imley-Horn and Associates, Inc. 8603 South Dixie Hwy Suite 411 Miami, Florida 33143 Phone: 305--662.6445 Fax: 305--662.6492 INFINITY II KHA Proj. No. 042339001 MIAMI-DADE COUNTY FLOOD CRITERIA MAP • • SW 13iri Si Zo I�]X Nearest Zo F.I,R.M. Base FIo• c , evation E:1111111111111/9 Kimley-Horn and Associates, Inc. 8fiO3 South Dixie Hwy Suite 411 Miami, Florida 33143 Phone: 305-662.6445 Fax: 305-562.6492 INFINITY II KHA Proj. No. 042339001 FIRM BASE FLOOD ELEVATION MAP • Attachment B Preliminary Drainage Well Calculations • .................................................................. DRAINAGE BASIN DATA 1. Site Data: A. Average Control Water Elevation (NGVD) = 2.00 Ivt DCPW ivlanWl Part 2 ,Sewn D-4,,Des q 4andaid.WC 2 Z B. County Flood Criteria Elevation (NGVD) = 5.00 (Go€i ity Flood Criteria Map see Apperi ix Aj C. F.I.R.M. Base Flood Elevation (NGVD) - X 11.00 (Map Ne 12Q25Cg791J, see Apx A) nearest to zone 2. Total Property Area : A. Impervious Areas: a) Asphalt and concrete pavement = b) Roof areas = c) 1/3 of the NE building corner = Total Impervious Area (A) _ B. Pervious areas: 1.300 Acres Acres Acres Acres (in excess of property area) 2.670 Acres (100.00%) a) Green Areas = 0 000 Acres (0.00%) C. Total Contributing Area = 3. Weighted Runoff Coefficient (C): Runoff Coefficient Impervious (C1) = Runoff Coefficient Pervious (C2) = C=[(Al xCI) +(A2 xC2)}/A; C= C x A= Total Contributing Area; C x A Acres 0.900 2.40 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° i 1) + t (0.5895 + F- )] Frequency (F) 5 years Frequency Curve Q = CIA, V = Qt; V (j , = Qt0 ;To, to in.) = Time to generate 1 inch of runoff V(t in.) = CIAt(I irk.) 1" x A = C1Attz i) ; Solving for to in ), to in.) = 1" / (IC) Time to Generate one inch of run-off t(in) = 11.02 Min. Time to reach the inlet (tc.) 10 00 Min. Total Time required to generate 1 in of runoff = 21.02 Min. Drainage Basin Data 1/5/2005 Infinity II at Brickell City of Miami, Florida DRAINAGE WELL CALCULATIONS: I. Cumulative Runoff (inflow Mass Diagram) (Min.) (Sec.) Accumulated Storm Runoff (CF) 8 10 15 21.02 30 40 50 60 90 120 180 480 600 900 1261 1800 2400 3000 3600 5400 7200 10800 2.403 2.403 2.403 2.403 2.403 2.403 2.403 2.403 2.403 2.403 2.403 6.405 6.166 5.641 5.117 4.493 3.956 3.534 3.193 2.477 2.023 1.480 15.39 14.82 13.56 12.30 10.80 9.51 8.49 7.67 5.95 4.86 3.56 7,388 8,891 12,200 15,504 19,435 22,818 25,478 27,626 32,141 35,002 38,421 2. Drainage Well Design Discharge Rate: Based on well discharge rate of: Well Structure Top Slab Thickness = Ground Cover Over Top Slab = Lowest Tnlct Rtro .lev DW-1 DW-2 DW-3 can High Tide Elev. 2.00 2.00 2.00 Headless due to 1Itgher SG of Salt Water (ft) 1.50 1.50 7.40 7.40 7.40 9 GPM/ft. Head (see note 1 below) inches inches Discharge to (CFS), 8.24 8.24 8.24 Well Structure idth (f, 6.00 6.00 Length (ft.) 12.00 12.00 ell Structure: Storage Volume (CF). 424.8 424.8 424.8 Well Discharge Rate (CFS) 24.73 Total Storage (CF) 1274.40 NOTES: 1) The design well discharge rate of 500 GPM/it. head used in this calculation is based on an average of three well completion reports provided by Jailer Associates,. Inc. for a project located at the NE corner of SW 13th Street and South Miami Avenue called Brickell View. Drainage Well Calculations 1/5/2005 Infinity II at Brickell City of Miami, Florida 3. Detention Time: Qd = Design Runoff Rate = 12.30 CFS Vd = Detention Volume (CF) = Qd x 90 sec. = 1106.63 CF Vdi = Detention Volume Per Well = 368.88 CF W = Width of Well Structure = 6.0 ft. L = Length of Well Structure = 12.0 ft. = Minimum Distance Required from Top of Casing to Floor of Well Box to Achieve 90 Second Detention Time: Hen.(ft.)=Vdl/(WxL) Clearance between Top Slab and Top of Well Casing = Interior Height of Well Box (Z) 4. Excess storm water runoff excluding well structure storage: 5.20 2 7.20 8 10 15 21.02 30 40 50 60 90 120 180 (Sec,) 480 600 900 1,260.95 1800 2400 3000 3600 5400 7200 10800 Well Discharge Rate CFS) 24.73 24.73 24.73 24.73 24.73 24.73 24.73 24.73 24.73 24.73 24.73 Accumulated' Well Discharge Volume (CF) 11,872 14,840 22,259 31,187 44,519 59,358 74,198 89,037 133,556 178,075 267,112 Accurriulated Storm Runoff (C). 7,388 8,891 12,200 15,504 19,435 22,818 25,478 27,626 32,141 35,002 38,421 Total Overflow Volume (C) -4,484 -5,949 -10,059 -15,682 -25,084 -36,541 -48,720 -61,412 - 101,415 -143,073 -228,691 ft. ft. ft. 5. Excess storm water runoff including well structure storage: Accuinulated Statin Runoff (( Storage Well Structure (CF) Discharge Volume Total O erklow Valurne (CF) 8 10 15 21.02 30 40 50 60 90 120 180 480 600 900 1,260.95 1800 2400 3000 3600 5400 7200 10800 7,388 8,891 12,200 15,504 19,435 22,818 25,478 27,626 32,141 35,002 38,421 1,274 1,274 1,274 1,274 1,274 1,274 1,274 1,274 1,274 1,274 1,274 11,872 14,840 22,259 31,187 44,519 59,358 74,198 89,037 133,556 178,075 267,112 -5,758.43 - 7,223.31 - 11,333.54 -16,956.53 -26,358.26 -37,815.I7 -49,994.04 - 62,686.01 -102,689.35 -144,347.60 -22,9,965.67 Safety Factor 2.01% Safety Factor 2.19% Drainage Well Calculations 1/5/2005 • Attachment C Hxisting Utility Records • • 8603 South Dixie Hwy Suite 411 Miami, Florida 33143 Kimley-Hom and Associates, Inc. Fhon : 305--662.6445 Fax: 305-662.6492 INFINITY II KHA Proj. No. 042339001 MDWASD WATER ATLAS SHEET • • PROJECT LOCATION ❑1111111� Kimley-Horn and Associates, Inc. 8603 South Dixie Hwy Suite 411 Miami, Florida 33143 Phone: 305-662.6445 Fax: 305-662.6492 INFINITY II KHA Proj. No. 042339001 MDWASD SEWER ATLAS SHEET Attachment D Pump Station Monthly Information M Staff, Station Station Current Delta R Type Owner Number Projec Proposed Number ofET (Hrs) ET (Hrs) ET {H P gallons (ypd): 117338 OK` A52M4- 30 0001 OAC 30 CD AC 30 RS IN 30 RS95APR IN 30 RS94MAR • • Downstream Stations *****#***,k**************** 6.11 0.02 6 1001.81 0.02 1001 1001.88 0.01 1001 1001.62 0.01 1001 1001.75 0.01 1001