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HomeMy WebLinkAboutIII.3 - Site Utility StudyWOLFBEFLG ALVAR EZ MIAMI RIVERTOWN MIAMI, FLORIDA SITE UTILITY STUDY MARCH 22, 2005 1500 SAN REMO AVENUE SUITE 300 CORAL GABLES, FLORIDA 33173 TEL 305-666-5474 FAX 305-666-4994 AA 0002416 EB 0002354 WA PROJECT NO. 24015.00 • TABLE OF CONTENTS Section Page I. Introduction 2 II. Site Conditions 2 III. Drainage 3 IV. Water Distribution 5 V. Sanitary Sewer 6 VI. Natural Gas 6 Exhibits 'A' Location Map Aerial Photograph Survey `B' Existing Drainage Existing Water Existing Sewer Existing Gas `C' Drainage Calculations `D' Water Consumption Sanitary Sewer Flow 1 • • I. INTRODUCTION Miami Rivertown is a planned mixed -use development proposed to be located on the banks of the Miami River in Miami, Florida. The site is located within two City blocks bounded by N.W North River Drive to the North, N.W. 14th Avenue to the East, the Miami River to the south and a private property owned by FRB Corporation to the West. Miami -Dade County records show the property being owned by Mahi Shrine Holding Corp. The project consists of three separate high-rise structures that will be built in three phases. Each building will have a seven -story parking base with retail, office and townhomes around the periphery. Additionally, Phase I will have 28 floors, and Phases II and III, 27 floors of condominium units above the bases. The eighth floor will house condominium units as well as tenant amenities such as an exercise room, activity room, business center, rooftop garden and swimming pool. The total planned development will consist of approximately the following: • Residential 985 Units • Retail 47,862 g.s.f. • Restaurant 3,183 g.s.f. • Office 98,129 g.s.f. • Parking Garage 1,866 spaces The initial phase of construction will include the improvements to the riverfront boardwalk, N.W. 15th Avenue and construction of the new access road on the east side of the site. II. SITE CONDITIONS The site is traversed by N.W. 15th Avenue which will remain a public right-of-way. The site is subdivided into a number of lots and is currently improved with three one-story and one three-story concrete block and stucco (CBS) buildings, miscellaneous structures and paved areas. Refer to Location Map, aerial photograph and copy of the Survey in Exhibit 'A'. 2 III. DRAINAGE A. EXISTING DRAINAGE For the purpose of the drainage analysis, the total area to be developed is approximately 6.42 acres of private property. This excludes submerged lands that may be within the limits of the property. Additionally, 0.75 acres of the N.W. 15th Avenue right-of-way that will be improved as part of the project, is being considered as well. Therefore, the entire project will consist of three (3) drainage areas (basins) as a result of the property being bisected by N.W. 15th Avenue. For the purpose of this study, the three drainage basins will be referred to as the West, 15th Ave. (or center) and East basins, with drainage areas of approximately 1.66 acres, 0.75 acres, and 4.76 acres respectively. Site visits and reviews of the project's Survey (included in Exhibit 'A') and City of Miami drainage system records (included in Exhibit `B') indicate existing drainage structures within the East Basin, 15th Avenue Basin and along N. River Drive. None are apparent on the West Basin. It appears that runoff from the buildings and paved areas within the West Basin presently infiltrate the rather extensive sodded areas with some runoff going into the adjacent streets and into the street drainage systems owned and maintained by the City of Miami. The 15t'' Avenue Basin (a public right-of-way) includes three catch basins on the south end of the Avenue. The two southernmost inlets are connected to 24-inch diameter outfalls discharging into the Miami River. The East Basin is almost entirely paved and contains only one catch basin. Based on the grading data from the survey, it is apparent that runoff from the site sheet flows partially to the west into N.W. 15th Avenue and to the south into the Miami River. This condition is not in compliance with current regulations. The existing drainage system on North New River Drive adjacent to the site consists of two separate systems, one to the east and one to the west. Both systems appear to eventually discharge into the Miami River. For the most part, drainage is non-existent on North River Drive in front of the site, and it appears that the City of Miami's street 3 • • drainage systems adjacent to the limits of the project will have to be improved in compliance with current environmental regulations. B. ON -SITE DRAINAGE The planned development will be characterized by an overall imperviousness of approximately 85%, while providing approximately 15% pervious area in the form of at - grade landscape areas and planters. The entire site will be filled and compacted, and the landscape areas are likely to be in planters or bordered by curbs. Therefore, runoff from the impervious areas is not expected to reach the pervious areas. The proposed drainage systems for each drainage area will be designed to retain the runoff generated by the proposed buildings and site development with emergency overflows discharging into the Miami River as added safety features. Depending on the results from a forthcoming soils report, either exfiltration trenches or drainage wells will be installed within each drainage area to provide the required capacity necessary to retain, treat and dispose of the runoff generated by the design storm as required by the Dade County Department of Environmental Resources Management (DERM), Water Control Section. Runoff generated by the building and site improvements for the East and West drainage basins will be collected by series of interconnected site and roof drainage structures and conveyed to drainage disposal systems sized to meet DERM requirements. In addition, runoff generated inside the parking garages will be routed into isolated exfiltration trenches with sand filter in compliance with recent DERM requirements. The proposed drainage system shall be designed to be able to keep the project dry for the 5 Year — 24 Hour storm, and keep the finished floor protected for the 100 Year — 72 Hour storm. 4 Note that one-third of the area of two adjacent building walls have been added to the total drainage acreage to allow for runoff generated by driving rain. If the hydraulic conductivity of the soils is poor, it will warrant the installation of drainage wells and will likely require 3, 1, and 7 wells, or for the East, Center and West basins respectively as indicated on the Drainage Well Calculations in Exhibit `C'. If the hydraulic conductivity of the soils is favorable to the installation of exfiltration trenches, a total of approximately 800 linear feet of trench will be required. Refer to Exhibit `C' for preliminary drainage well and exfiltration trench calculations. IV. WATER DISTRIBUTION The Miami -Dade Water and Sewer Department (MDWASD) provides water service for the area in which the project is located. Refer to the Exhibit `B' for a copy of MDWASD's water atlas depicting their water distribution system in the vicinity of the property. According to the water atlas, MDWASD owns and operates the following water mains within N.W. North New River Drive adjacent to the proposed project: • 12" water main on the north side of the street. • 36" and 48" ductile iron pipe (D.I.P.) water main on the south side of the street. It is not anticipated that MDWASD will require the construction of any new water mains as part of this project. However, a new water main loop for fire protection will be required for the project. This water main will likely extend south on N.W. 15th Ave. to the proposed Connector road, looping back to N. River Drive. The domestic, fire and irrigation services for the new buildings will be provided from either the existing water mains on N. River Drive or the aforementioned new water main loop. 5 • The anticipated average daily water consumption for this project will be 219,141 GPD, as noted in the calculations shown on Exhibit `D'. V. SANITARY SEWER MDWASD also provides sewer service in this area. Refer to Exhibit `B' for a copy of MDWASD's sewer atlas depicting their existing sewer system in the vicinity of the property. According to the sewer atlas, MDWASD owns and operates the following sewer mains with on North New River Drive: • 8" gravity sewer main on the north side of the street. • 54" gravity sewer main on the north side of the street south of the 8" main. The sanitary sewer service for the planned buildings will be provided by way of connecting into the existing 54" sewer main. All sewage flows generated by the project will be collected in the existing MDWASD gravity sewer systems and conveyed downstream to MDWASD Pump Station #1. According to DERM, Wastewater Section, the pump station presently has adequate capacity remaining to handle the anticipated flows to be generated by this project. The anticipated average daily sewage flow for this project will be 219,141 GPD, as noted in the calculations shown in Exhibit `D'. VI. NATURAL GAS TECO Peoples Gas Systems, Inc. owns and operates a 2" natural gas main on North River Drive just west of N.W 15th Avenue and another 2" natural gas main at North River Drive and N.W. 14th Avenue. Both Gas mains currently operate at 30 psi. Natural gas services may be connected to these existing mains. However, depending on load requirements, the existing mains may need to be upgraded. • LOCATION MAP C SCALE: 1" = 300' • MIAMI RIVERWALK AERIAL PHOTOGRAPH z La > r FRB CORPORATION OWNER SIC Se' ( sz M/qM/ R/'tR -� (C Z LEGEND AND SYMBOLS jf Ca. Boaln u0ity Po1. - - O.an.m Willy Lim ca�s Catormt• aaa storm.. Fa Found O Po1N.9 Spar (0) Record (F) nod N.e 0. Nei end O. Fr• Ny.unt LP. Mat RP* O CIF. Obi. L. rm. Cect.. Lit. ALTA/ACSM LAND TITLE SURVEY (URBAN) e=1171°t;. - .. s.31440 J7.eG "WNW LF. im Irvin IJL Iran R.lor Cmw.b p .1.1 .,at Li411 Pot. • Conc. Pole rw Electric Ra .4 Exist. 0.w00n e Non. 6. OEHOSES 111101CAP PAR.NO SPACE - 11.17 ItlIlemumml tin. ENCIL Onmd1 SF. Sterne I..1 4/14/ R/1/4._R GRAPHIC SCALE 40 0 20 40 4 180 - (areef l THIS ll X 17- COPY 1 Inch m 100 IL Navitalgnialf Rosin, mg SPFCIAL NOTES: No.. rm... tM Ewm al ttileSNm.. 0al m. Cmmvonat al0 ( a n .P0 A0n1 Fl. NMont Pis DM MOOD pm.a0, , Fmk Maar. in...Mora ...any dol.d came 30202 and 1 did not W mI i1m Wt m .. 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S....1 .0y Mob,. ma cam. a AL1A/AC1a * .SP} e0 .2 Tonto A ammo P.em a t2. llo nv�imsl15Immt. mum 0a 0, .LTA NSPSm A.60m F.ect m0l. dot.alml.v40, e.,4000 ay =mmm m ram 1* 0 .t An1. Oar; m a� rmrw'.Ym00tb%a' Sur. maw., NM Gtw .. Iowa Ira ALTA/AC.1 Loyd Ma S e . FLORIDA INTERNATIONAL LAND SURVEYORS, INC ram w45. 11182r. awa. A DOD vt-.m S11RVFYOR'C NOTES. t. L.Ool aaerodm m Ion*, m. 0.1 0. L.Ool am01N1 .apn 1a a7 a.aka0m0 AM.O.m. 1a1Mb4 re... c .m111b al rm. 1 Ioo.P••m Ina* ae u0n0u. Y m} .et bm1.4 • Onrm24 m lalan- 0 .1} net dalann tr. 1 NI dmatim. Il my. rmm 1e K. lam. a m 0aa115N Amu. i 0 Hu�1 Sb_1 moL Fbbe IL NA10050. FLOW INSURANCE ROMAN 0.ALt Comma.. 1]0650 P. .m Ne0 J Floo.2 d 20 0r E era Flood O.Mbe bo' Fin. orals 0l-1T-05 D. m r .y Nm e..n plena In w .12 m el Um.Mus lmntra Mr. m 01. Fa0nm0m more rat u1a1 b MI mumW prat} L.6 Nal valid Mein .al.d mN m rm.. .Ammer mm- Vicente Tune rm 1 5iR .Ita nn5 • FLORIDA WTERNAI'IONCL LAND SURVEYORS, INC. ALTA/ACSM LAND TITLE SURVEY 1500 NORTH RIVER DRIVE IIIAI2-DADS COUNTY, FLORIDA DRAWN JAI p.14 0Y1v0. 50.0. ENV Iu11Y TEIPLE el • EXHIBIT `B' • EXISTING DRAINAGE SCALE: 1" = 300' • • \ EXISTING WATER J SCALE: 1" = 300' SCALE: 1" = 300' • • 11 EXISTING SEWER SCALE: 1" = 300' • • • ri-EXISTING GAS } SCALE: 1" = 300' • • EXHIBIT 'C' • Miami Rivertown STORM DRAINAGE CALCULATIONS January 19, 2005 WOLFBEKG ALVA R. E Z 1500 SAN REMO AV EN U E SUITE 300 CORAL GABLES. FLORIDA 331463 TEL (305) 666-5474 FAX (305) 666-4994 AA 0002416 EB 0002354 Project No. 24015.00 • MIAMI RIVERTOWN DRAINAGE WELL CALCULATIONS The site runoff is computed by the rational method: Q = cia, where: Q = Runoff in cfs c = Runoff coefficient i = rainfall intensity in in/hr a = Area in acres Drainage computation data: Design storm S = 5-year, 1-day Time of concentration t = 10-minute Intensity i = 6.2 in/hr Runoff coefficient c = 0.95 Surface area SaE = 72,267 sq. ft. (1.66 ac.) Sac = 32,478 sq. ft. (0.75 ac.) Saw = 207,197 sq. ft. (4.76 ac.) 1/3 building wall area WaE = 1/3 x 109,165 sq. ft. (0.84 ac.) Wac = 0 sq. ft. Waw = 1/3 x 220,851 sq. ft. (1.69 ac.) Total contributing area TaE = 2.50 ac. Tat = 0.75 ac. Taw = 6.45 ac. Miami -Dade County Flood Criteria = 5.00 N.G.V.D. F.E.M.A. Base Flood Elevation = 9.00 N.G.V.D. Ave. October ground water table = 2.00 N.G.V.D. Runoff Generated: Q = cia QE & Qw Q = (0.9)(6.2)(0.85Sa + Wa) + (0.3)(6.2)(0.15Sa) Qc Q = (0.9)(6.2)(0.85Ta) + (0.3)(6.2)(0.15Ta) QE = 13.02 cfs (5,844 GPM) Qc = 3.77 cfs (1,691 GPM) Qw = 34.80 cfs (15,170 GPM) Based on information received from Jaffer Associates, Ltd., a drilling company with much experience in South Florida, in this geographic area a 24-inch diameter well disposes 750 GPM per foot of head. Assuming a maximum of 3 feet of head, the estimated required wells are: East Basin = 3 wells Center Basin = 1 well West Basin = 7 wells • Miami Rivertown Exfiltration Trench Calculations EAST Basin k: Surface Area = 1.66 acres. Building Wall Contribution = 0.84 acres. Total Drainage Area = 2.50 acres. Impervious Area = 2.25 acres. Pervious Area = 0.25 acres. Lowest Grnd. Elev. for Prop. Exfil. Trench = 5.00 ft. NGVD. Lowest Existing Grate Elevation = 5.00 ft. NOVD. Top Elevation -�-� Inv. Elevation GWT Bottom Elevation Proposed Exfiltration Trench: Top Elevation = 4.00 ft. NGVD. GWT = 2.00 ft. NGVD. Pipe Diameter = 18 inches Inv. Elevation = 0.50 ft. NGVD. Bottom Elevation = -6.00 ft. NGVD. Width = 4.00 feet. Weir Elevation = n/a ft. NGVD. Existing Exfiltration Trench: Top Elevation = n/a ft. NGVD GWT = n/a ft. NGVD Pipe Diameter = n/a inches Inv. Elevation = n/a ft. NGVD Bottom Elevation = n/a ft. NGVD Width = n/a feet. Length = n/a feet. Assumed Usage = 0 percent (C = 0.9 ) (C = 0.3 ) Weighted k = 5.00E-04 cfs/sf-ft of head. Safety Factor = 1-.5 DESIGN STORM FREQUENCY (YEARS): 5 MINIMUM TIME OF CONCENTRATION (MINUTES): 1'0.00 Width Assumed k value pending percolation test results • TOTAL DRAINAGE AREA = 1.012 hectares or 2.500 acres. TOTAL IMPERVIOUS DRAINAGE AREA = 0:911 hectares or 2.251 acres. IMPERVIOUS RUNOFF COEFFICIENT = 0.90 TOTAL PERVIOUS DRAINAGE AREA = 0.101 hectares or 0.249 acres. PERVIOUS RUNOFF COEFFICIENT = 0.30 SUB -BASIN DRAINAGE AREA = 1.012 hectares or 2.500 acres. SUB -BASIN IMPERVIOUS DRAINAGE AREA = 0.911 hectares or 2.251 acres. IMPERVIOUS RUNOFF COEFFICIENT = 0.90 SUB -BASIN PERVIOUS DRAINAGE AREA = 0.101 hectares or 0.249 acres. PERVIOUS RUNOFF COEFFICIENT = 0.30 SUB -BASIN TIME OF CONCENTRATION = 11.00 minutes DESIGN STORM FREQUENCY = 5 years SUB -BASIN TIME OF CONCENTRATION = r0.00 minutes SUB -BASIN TIME FOR FIRST INCH OF RUNOFF = 12.14 minutes REQUIRED WATER QUALITY TREATMENT TIME = 22.14 minutes TREATMENT VOLUME REQUIRED: Vtrmt = 397.632 cu. meters or Vtrmt = 0.040 hectare -meters or 14042.14127 L = Volume / [k / SF x (2 x H2 x Du - Du^2 + 2 x H2 x Ds) + (1.39 x 10'.4) x ( W x Du + PS)] Volume = Treatment Vol. - Capacity of Exist. Trench (ac-in) k = Weighted Hyd. Conductivity (cfs/sf - ft) H2 H2 = Depth to the Water Table (ft) W = Trench width (ft) Du = Non -Saturated Trench Depth (ft) Ds = Saturated Trench Depth (ft) SF = Safety Factor PS = Pipe Storage(ft.^3) Capacity of Exist. Exfil. Trench = 0.000 ha-m or Treatment Volume = 0.040 ha-m or Volume = 3.868 ac-in. k = 0.000500 cfs/sf-ft H2 = 3.00 ft. W = 4.00 ft. Du = 2.00 ft. Ds = 8.00 ft. SF = 1.50 0.000 ac.-ft. 0.32 ac.-ft. w • kVL.J wkL.IIA • 120.00 100.00 80.00 60.00 40:00 20.00 0.00 MASS DIAGRAM 0 20 40 60 80 100 TIME (MINUTES) 120 140 160 -RUNOFF INFLOW INFLOW MINUS STORAGE MAX REQUIRED EXFIL. RATE OVERFLOW 180 MAXIMUM OVERFLOW RATE = 0.00 CFS • • • MAXIMUM EAST Basin ADJUSTED PROPOSED REQUIRED REQUIRED ACTUAL RAINFALL INFLOW INFLOW EXIST. F.D. INFLOW F.D. EXCESS EXFIL. EXFIL. EXFIL. OVERFLOW OVERFLOW TIME INTENSITY RATE VOLUME CAPACITY VOLUME STORAGE RUNOFF RATE VOLUME VOLUME VOLUME RATE (MIN.) CA (IN/HR) (CFS) (FT.A3) (FT.A3) (1013 C.F.) (FT.^3) (10^3 C.F.) (CFS) (1013 C.F.) (1013 C.F.) (10^3 C.F.) (CFS) 0 2.125 0.00 0.00 0.00 0.000 0.00 2080.00 0.00 0.00 0.00 0.00 0.00 0.00 5 2.125 6.80 14.45 4335.25 0.000 4.34 2080.00 2.26 0.00 2.90 2.91 0.00 0.00 10 2.125 6.17 13.11 7864.62 0.000 7.86 15 2.125 5.64 11.99 10793.70 0.000 10.79 2080.00 5.78 2080.00 8.71 9.64 9.68 5.81 8.71 5.82 8.74 0.00 0.00 0.00 0.00 20 2.125 5.20 11.05 13263.64 0.000 13.26 2080.00 11.18 9.32 ' 11.62 11.65 0.00 0.00 25 2.125 4.82 10.25 15374.55 0.000 15.37 2080.00 13.29 8.86 14.52 14.56 0.00 0.00 30 2.125 4.50 9.56 17199.41 0.000 17.20 2080.00 15.12 8.40 17.43 17.47 0.00 0.00 35 2.125 4.21 8.95 18792.67 0.000 18.79 2080.00 16.71 7.96 40 2.125 3.96 8.41 20195.80 0.000 20.20 2080.00 18.12 7.55 45 2.125 3.74 7.94 21440.90 0.000 21.44 2080.00 19.36 7.17 50 2.125 3.54 7.52 22553.26 0.000 22.55 2080.00 20.47 6.82 55 2.125 3.36 7.14 23553.03 0.000 23.55. 2080.00 21.47 6.51 60 2.125 3.20 6.79 24456.47 0.000 24.46 2080.00 22.38 6.22 65 2.125 3.05 6.48 25276.87 0.000 25.28 2080.00 23.20 5.95 70 2.125 2.92 6.20 26025.18 0.000 26.03 2080.00 23.95 5.70 75 2.125 2.79 5.94 26710.50 0.000 26.71 2080.00 24.63 5.47 80 2.125 2.68 5.70 27340.45 0.000 27.34 2080.00 25.26 5.26 85 2.125 2.58 5.47. 27921.50 0.000 27.92 2080.00 25.84 5.07 90 2.125 2.48 5.27 28459.12 0.000 28.46 2080.00 26.38 4.89 95 2.125 2.39 5.08 28958.00 0.000 28.96 2080.00 26.88 4.72 100 2.125 2.31 4.90 29422.19 0.000 29.42 2080.00 27.34 4.56 105 2.125 2.23 4.74 29855.18 0.000 29.86 2080.00 27.78 4.41 110 2.125 2.16 4.58 30260.02 0.000 30.26 2080.00 28.18 4.27 115 2.125 2.09 4.44 30639.36 0.000 30.64 2080.00 28.56 4.14 120 2.125 2.03 4.30 30995.55 0.000 31.00 2080.00 28.92 4.02 125 2.125 1.97 4.18 31330.63 0.000 31.33 . 2080.00 29.25 3.90 130 2.125 1.91 4.06 31646.43 0.000 31.65 2080.00 29.57 3.79 135 2.125 1.86 3.94 31944.57 0.000 31.94 2080.00 29.86 3.69 140 2.125 1.81 3.84 32226.49 0.000 32.23 2080.00 30.15 3.59 145 2.125 1.76 3.73 32493.47 0.000 32.49 2080.00 30.41 3.50 150 2.125 1.71 3.64 32746.68 0.000 32.75 2080.00 30.67 3.41 155 2.125 1.67 3.55 32987.15 0.000 32.99 2080.00 30.91 3.32 160 2.125 1.63 3.46 33215.83 0.000 33.22 2080.00 31.14 3.24 165 2.125 1.59 3.38 33433.55 0.000 33.43 2080.00 31.35 3.17 170 2.125 1.55 3.30 33641.08 0.000 33.64 2080.00 31.56 3.09 175 2.125 1.52 3.22 33839.13 0.000 33.84 2080.00 31.76 3.02 180 2.125 1.48 3.15 34028.34 0.000 34.03 2080.00 31.95 2.96 20.33 23.24 26.14 29.05 31.95 34.85 37.76 40.66 43.57 46.47 49.38 52.28 55.19 58.09 61.00 63.90 66.81 69.71 72.61 75.52 78.42 81.33 84.23 87.14 90.04 92.95 95.85 98.76 101.66 104.56 20.38 23.30 26.21 29.12 32.03 34.94 37.86 40.77 43.68 46.59 49.50 52.42 55.33 58.24 61.15 64.06 66.98 69.89 72.80 75.71 78.62 81.54 84.45 87.36 90.27 93.18 96.10 99.01 101.92 104.83 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Miami Rivertown Exfiltration Trench Calculations CENTER Basin Surface Area = 0.75 acres. Building Wall Contribution = 0 acres. Total Drainage Area = 0.75 acres. Impervious Area = 0.64 acres. Pervious Area = 0.11 acres. Lowest Gmd. Elev. for Prop. Exfil. Trench = 5.00 ft. NGVD. Lowest Existing Grate Elevation = 5.00 ft. NGVD. Proposed Exfiltration Trench: Top. Elevation Inv. Elevation GWT (C = 0.9 ) (C = 0.3 ) Bottom Elevation F Top Elevation = 4.00 ft. NGVD. GWT = 2.00 ft. NGVD. Pipe Diameter = 18 inches Inv. Elevation = 0.50 ft. NGVD. Bottom Elevation = -6.00 ft. NGVD. Width = 4.00 feet. Weir Elevation = n/a ft. NGVD. Existing Exfiltration Trench: Top Elevation = n/a ft. NGVD GWT = n/a ft. NGVD Pipe Diameter = n/a inches Inv. Elevation = n/a ft. NGVD Bottom Elevation = n/a ft. NGVD Width = n/a feet. Length = n/a feet. Assumed Usage = 0 percent Weighted k = 5.00E-04 cfs/sf-ft of head. Safety Factor = 1.5 DESIGN STORM FREQUENCY (YEARS): 5 MINIMUM TIME OF CONCENTRATION (MINUTES): 10.00 Width Assumed k value pending percolation test results TOTAL DRAINAGE AREA = 0.304 hectares or TOTAL IMPERVIOUS DRAINAGE AREA = 0.258 IMPERVIOUS RUNOFF COEFFICIENT = 0.90 TOTAL PERVIOUS DRAINAGE AREA = 0.046 PERVIOUS RUNOFF COEFFICIENT = 0.30 hectares or hectares or 0.750 acres. 0.638 acres. 0.113 acres. SUB -BASIN DRAINAGE AREA = 0.304 hectares or 0.750 acres. SUB -BASIN IMPERVIOUS DRAINAGE AREA = 0.258 hectares or 0.638 acres. IMPERVIOUS RUNOFF COEFFICIENT = 0.90 SUB -BASIN PERVIOUS DRAINAGE AREA = 0.046 hectares or 0.113 acres. PERVIOUS RUNOFF COEFFICIENT = 0.30 SUB -BASIN TIME OF CONCENTRATION = 10.00 minutes DESIGN STORM FREQUENCY = 5 years SUB -BASIN TIME OF CONCENTRATION = 10.00 minutes SUB -BASIN TIME FOR FIRST INCH OF RUNOFF = 12.72 minutes REQUIRED WATER QUALITY TREATMENT TIME = 22.72 minutes TREATMENT VOLUME REQUIRED: Vtrmt = 116.996 cu. meters or Vtrmt = 0.012 hectare -meters or 4131.654803 L = Volume / [k / SF x (2 x H2 x Du - Du''2 + 2 x H2 x Ds) + (1.39 x 10^-4) x (W x Du + PS)] Volume = Treatment Vol. - Capacity of Exist. Trench (ac-in) k = Weighted Hyd. Conductivity (cfs/sf - ft) H2 H2 = Depth to the Water Table (ft) W = Trench width (ft) Du = Non -Saturated Trench Depth (ft) Ds = Saturated Trench Depth (ft) SF = Safety Factor PS = Pipe Storage (f1.^3) Capacity of Exist. Ex51. Trench = 0.000 ha-m or Treatment Volume = 0.012 ha-m or Volume = 1.138 ac-in. k = 0.000500 cfs/sf-ft H2 = 3.00 ft. W = 4.00 ft. Du = 2.00 ft. Ds = 8.00 ft. SF = 1.50 0.000 ac: ft. 0:09 w • • 35.00 30.00 25.00 u. cii 20.00 0 w 0 15.00 10.00 5.00 0.00 0 20 40 60 MASS DIAGRAM 80 100 TIME (MINUTES) 120 140 160 180 180 ....RUNOFF INFLOW • INFLOW MINUS STORAGE MAX REQUIRED EXFIL RATE OVERFLOW MAXIMUM OVERFLOW RATE = 0.00 CFS • • MAXIMUM CENTER Basin ADJUSTED PROPOSED REQUIRED REQUIRED ACTUAL RAINFALL INFLOW INFLOW EXIST. F.D. INFLOW F.D. EXCESS EXFIL. EXFIL. EXFIL. OVERFLOW OVERFLOW TIME INTENSITY RATE VOLUME CAPACITY VOLUME STORAGE RUNOFF RATE VOLUME VOLUME VOLUME RATE (MIN.) CA (IN/HR) (CFS) (FT.^3) (FT."3) (10^3 C.F.) (FT.^3) (10^3 C.F.) (CFS) (10^3 C.F.) (10^3 C.F.) (10^3 C.F.) (CFS) 0 0.608 0.00 0.00 0.00 0.000 0.00 600.00 0.00 0.00 0.00 0.00 0.00 0.00 5 0.608 6.80 4.13 1239.43 0.000 1.24 600.00 0.64 0.00 0.83 0.84 0.00 0.00 10 0.608 6.17 3.75 2248.46 0.000 2.25 600.00 1.65 2.75 1.66 1.68 0.00 0.00 15 0.608 5.64 3.43 3085.87 0.000 3.09 600.00 2.49 2.76 2.49 2.52 0.00 0.00 20 0.608 5.20 3.16 3792.02 0.000 3.79 600.00 3.19 2.66 3.31 3.36 0.00 0.00 25 0.608 4.82 2.93 4395.52 0.000 4.40 600.00 3.80 2.53 4.14 4.20 0.00 0.00 30 0.608 4.50 2.73 4917.24 0.000 4.92 600.00 4.32 2.40 4.97 5.04 0.00 0.00 35 0.608 4.21 2.56 5372.75 0.000 5.37 600.00 4.77 2.27 5.80 5.88 0.00 0.00 40 0.608 3.96 2.41 5773.89 0.000 5.77 600.00 5.17 2.16 6.63 6.72 0.00 0.00 45 0.608 3.74 2.27 6129.86 0.000 6.13 600.00 5.53 2.05 7.46 7.56 0.00 0.00 50 0.608 3.54 2.15 6447.88 0.000 6.45 600.00 5.85 1.95 8.29 8.40 0.00 0.00 55 0.608 3.36 2.04 6733.71 0.000 6.73 600.00 6.13 1.86 9.11 9.24 0.00 0.00 60 0.608 3.20 1.94 6992.00 0.000 6.99 600.00 6.39 1.78 9.94 10.08 0.00 0.00 65 0.608 3.05 1.85 7226.55 0.000 7.23 600.00 6.63 1.70 10.77 10.92 0.00 0.00 70 0.608 2.92 1.77 7440.49 0.000 7.44 600.00 6.84 1.63 11.60 11.76 0.00 0.00 75 0.608 2.79 1.70 7636.42 0.000 7.64 600.00 7.04 1.56 12.43 12.60 0.00 0.00 80 0.608 2.68 1.63 7816.52 0.000 7.82 600.00 7.22 1.50 13.26 13.44 0.00 0.00 85 0.608 2.58 1.57 7982.64 0.000 7.98 600.00 7.38 1.45 14.09 14.28 0.00 0.00 90 0.608 2.48 1.51 8136.34 0.000 8.14 600.00 7.54 1.40 14.92 15.12 0.00 0.00 95 0.608 2.39 1.45 8278.97 0.000 8.28 600.00 7.68 1.35 15.74 15.96 0.00 0.00 100 0.608 2.31 1.40 8411.68 0.000 8.41 600.00 7.81 1.30 16.57 16.80 0.00 0.00 105 0.608 2.23 1.35 8535.47 0.000 8.54 600.00 7.94 1.26 17.40 17.64 0.00 0.00 110 0.608 2.16 1.31 8651.21 0.000 8.65 600.00 8.05 1.22 18.23 18.48 0.00 0.00 115 0.608 2.09 1.27 8759.67 0.000 8.76 600.00 8.16 1.18 19.06 19.32 0.00 0.00 120 0.608 2.03 1.23 8861.50 0.000 8.86 600.00 8.26 1.15 19.89 20.16 0.00 0.00 125 0.608 1.97 1.19 8957.30 0.000 8.96 600.00 8.36 1.11 20.72 21.00 0.00 0.00 130 0.608 1.91 1.16 9047.58 0.000 9.05 600.00 8.45 1.08 21.54 21.84 0.00 0.00 135 0.608 1.86 1.13 9132.82 0.000 9.13 600.00 8.53 1.05 22.37 22.68 0.00 0.00 140 0.608 1.81 1.10 9213.42 0.000 9.21 600.00 8.61 1.03 .20 23.52 0.00 0.00 23 145 0.608 1.76 1.07 9289.75 0.000 9.29 600.00 8.69 1.00 2.03 24.36 0.00 0.00 150 0.608 1.71 1.04 9362.14 0.000 9.36 600.00 8.76 0.97 24.86 2520 0.00 0.00 155 0.608 1.67 1.01 9430.89 0.000 9.43 600.00 8.83 0.95 25.69 26..04 0.00 0.00 160 0.608 1.63 0.99 9496.27 0.000 9.50 600.00 8.90 0.93 26.52 26.88 0.00 0.00 165 0.608 1.59 0.97 9558.51 0.000 9.56 600.00 8.96 0.90 27.34 27.72 0.00 0.00 170 0.608 1.55 0.94 9617.84 0.000 9.62 600.00 9.02 0.88 28.17 28.56 0.00 0.00 175 0.608 1.52 0.92 9674.47 0.000 9.67 600.00 9.07 0.86 29.00 29.40 0.00 0.00 180 0.608 1.48 0.90 9728.56 0.000 9.73 600.00 9.13 0.85 29.83 30.24 0.00 0.00 Miami Rivertown Exfiltration Trench Calculations WEST Basin Surface Area = 4.76 acres. Building Wall Contribution = 1.69 asses. Total Drainage Area = 6.45 atins. Impervious Area = 5.74 acres. Pervious Area = 0.71 acres. Lowest Grnd. Elev. for Prop. Exfil. Trench = 5.00 ft. NGVD. Lowest Existing Grate Elevation = 5.00 ft. NGVD. Top Elevation Inv. Elevation GWT Bottom Elevation Proposed Exfiltration Trench: Top Elevation = 4.00 ft. NGVD. GWT = 2.00 ft. NGVD. Pipe Diameter = 18 inches Inv. Elevation = 0.50 ft. NGVD. Bottom Elevation = -6.00 ft. NGVD. Width = 4.00 feet. Weir Elevation = n/a ft. NGVD. Existing Exfiltration Trench: Top Elevation = n/a ft. NGVD GWT = n/a ft. NGVD Pipe Diameter = n/a inches Inv. Elevation = n/a ft. NGVD Bottom Elevation = n/a ft. NGVD Width = n/a feet. Length = n/a feet. Assumed Usage = 0 percent (C = 0.9 ) (C = 0.3 ) Weighted k = 5.00E-04 cfs/sf-ft of head. Safety Factor = 1.5 DESIGN STORM FREQUENCY (YEARS): 5 MINIMUM TIME OF CONCENTRATION (MINUTES): 10&00 • Width Assumed k value pending percolation test results • TOTAL DRAINAGE AREA = 2.610 hectares or TOTAL IMPERVIOUS DRAINAGE AREA = 2.321 hectares or IMPERVIOUS RUNOFF COEFFICIENT = 0.90 TOTAL PERVIOUS DRAINAGE AREA = 0,289 hectares or PERVIOUS RUNOFF COEFFICIENT = 0.30 SUB -BASIN DRAINAGE AREA = 2i610 hectares or SUB -BASIN IMPERVIOUS DRAINAGE AREA = 2,321 hectares or IMPERVIOUS RUNOFF COEFFICIENT = 0,90 SUB -BASIN PERVIOUS DRAINAGE AREA = 0.289 hectares or PERVIOUS RUNOFF COEFFICIENT = 0.30 SUB -BASIN TIME OF CONCENTRATION = 10.00 minutes DESIGN STORM FREQUENCY = 5 years 6.450 acres. 5.736 acres. 0.714 acres. 6.450 acres. 5.736 acres. 0.714 acres. SUB -BASIN TIME OF CONCENTRATION = 115.00 minutes SUB -BASIN TIME FOR FIRST INCH OF RUNOFF = 12.26 minutes REQUIRED WATER QUALITY TREATMENT TIME = 22.26 minutes TREATMENT VOLUME REQUIRED: Vtrmt = 1 021.542 cu. meters or Vtrmt = 0,102 hectare -meters or 36075.19729 L = Volume / [k / SF x (2 x H2 x Du - Du^2 + 2 x H2 x Ds) Volume = Treatment Vol. - Capacity of Exist. Trench (ac-in) k = Weighted Hyd. Conductivity (cfs/sf- ft) H2 H2 = Depth to the Water Table (ft) W = Trench width (ft) Du = Non -Saturated Trench Depth (ft) Ds = Saturated Trench Depth (ft) SF = Safety Factor PS = Pipe Storage (ft.^3) Capacity of Exist. Exfil. Trench = 0.000 ha-m or Treatment Volume = 0.102 ha-m or Volume = 9.938 ac-in. k = 0.000500 cfs/sf-ft H2 = 3.00 ft. W = 4.00 ft. Du = 2.00 ft. Ds = 8.00 ft. SF = 1.50 + (1.39 x 10A-4) x (W x Du + PS)] 0.000 ac.-ft. 0.83 ac.-ft. lagkr tMw 3E w • 300.00 250.00 200.00 LL 0 150.00 w 0 100.00 50.00 0.00 MASS DIAGRAM 0 20 40 60 80 100 TIME (MINUTES) 110 140 160 --- "".RUNOFF INFLOW INFLOW MINUS STORAGE MAX REQUIRED EXFIL. RATE OVERFLOW 180 MAXIMUM OVERFLOW RATE = 0.00 CFS • • • MAXIMUM WEST Basin ADJUSTED PROPOSED REQUIRED REQUIRED ACTUAL RAINFALL INFLOW INFLOW EXIST. F.D. INFLOW F.D. EXCESS EXFIL. EXFIL. EXFIL. OVERFLOW OVERFLOW TIME INTENSITY RATE VOLUME CAPACITY VOLUME STORAGE RUNOFF RATE VOLUME VOLUME VOLUME RATE (MIN.) CA (IN/HR) (CFS) (FT ^3) (FT ^3) (10^3 C.F.) (FT ^3) (109 C.F.) (CFS) (10^3 C.F.) (10^3 C.F.) (10^3 C.F.) (CFS) 0 5.628 0.00 0.00 0.00 0.000 0.00 5500.00 0.00 0.00 0.00 0.00 0.00 0.00 5 5.628 6.80 38.27 11481.72 0.000 11.48 5500.00 .5.98 0.00 7.70 7.70 0.00 0.00 10 5.628 6.17 34.72 20829.08 0.000 20.83 5500.00 15.33 25.55 15.39 15.40 0.00 0.00 15 5.628 5.64 31.76 28586.62 0.000 28.59 5500.00 23.09 25.65 23.09 23.10 0.00 0.00 20 5.628 5.20 29.27 35128.14 0.000 35.13 5500.00 29.63 24.69 30.78 30.80 0.00 0.00 25 5.628 4.82 27.15 40718.79 0.000 40.72 5500.00 35.22 23.48 38.48 38.50 0.00 0.00 30 5.628 4.50 25.31 45551.85 0.000 45.55 5500.00 40.05 22.25 46.17 46.20 0.00 0.00 35 5.628 4.21 23.70 49771.53 0.000 49.77 5500.00 44.27 21.08 53.87 53.90 0.00 0.00 40 5.628 3.96 22.29 53487.64 0.000 53.49 5500.00 47.99 19.99 61.56 61.60 0.00 0.00 45 5.628 3.74 21.03 56785.24 0.000 56.79 5500.00 51.29 18.99 69.26 69.30 0.00 0.00 50 5.628 3.54 19.91 59731.27 0.000 59.73 5500.00 54.23 18.08 76.96 77.00 0.00 0.00 55 5.628 3.36 18.90 62379.11 0.000 62.38 5500.00 56.88 17.24 84.65 84.70 0.00 0.00 60 5.628 3.20 17.99 64771.84 0.000 64.77 5500.00 59.27 16.46 92.35 92.40 0.00 0.00 65 5.628 3.05 17.17 66944.63 0.000 66.94 5500.00 61.44 15.76 100.04 100.10 0.00 0.00 70 5.628 2.92 16.41 68926.49 0.000 68.93 5500.00 63.43 15.10 107.74 107.80 0.00. 0.00 75 5.628 2.79 15.72 70741.52 0.000 70.74 5500.00 65.24 14.50 115.43 115.50 0.00 0.00 80 5.628 2.68 15.09 72409.94 0.000 72.41 5500.00 66.91 13.94 123.13 123.20 0.00 0.00 85 5.628 2.58 14.50 73948.81 0.000 73.95 5500.00 68.45 13.42 130.82 130.90 0.00 0.00 90 5.628 2.48 13.96 75372.66 0.000 75.37 5500.00 69.87 12.94 138.52 138.60 0.00 0.00 95 5.628 2.39 13.46 76693.93 0.000 76.69 5500.00 71.19 12.49 146.22 146.30 0.00 0.00 100 5.628 2.31 12.99 77923.31 0.000 77.92 5500.00 72.42 12.07 153.91 154.00 0.00 0.00 105 5.628 2.23 12.55 79070.07 0.000 79.07 5500.00 73.57 11.68 161.61 161.70 0.00 0.00 110 5.628 2.16 12.14 80142.27 0.000 80.14 5500.00 74.64 11.31 • 169.30 169.40 0.00 0.00 115 5.628 2.09 11.76 81146.94 0.000 81.15 5500.00 75.65 10.96 177.00 177.10 0.00 0.00 120 5.628 2.03 11.40 82090.28 0.000 82.09 5500.00 76.59 10.64 184.69 184.80 0.00 0.00 125 5.628 1.97 11.06 82977.73 0.000 82.98 5500.00 77.48 10.33 192.39 192.50 0.00 0.00 130 5.628 1.91 10.75 83814.12 0.000 83.81 5500.00 78.31 10.04 200.08 200.20 0.00 0.00 135 5.628 1.86 10.44 84603.73 0.000 84.60 5500.00 79.10 9.77 207.78 207.90 0.00 0.00 140 5.628 1.81 10.16 85350.37 0.000 85.35 5500.00 79.85 9.51 215.48 215.60 0.00 0.00 145 5.628 1.76 9.89 86057.47 0.000 86.06 5500.00 80.56 9.26 223.17 223.30 0.00 0.00 150 5.628 1.71 9.64 86728.09 0.000 86.73 5500.00 81.23 9.03 230.87 231.00 0.00 0.00 155 5.628 1.67 9.39 87364.96 0.000 87.36 5500.00 81.86 8.80 238.56 238.70 0.00 0.00 160 5.628 1.63 9.16 87970.59 0.000 87.97 5500.00 82.47 8.59 246.26 246.40 0.00 0.00 165 5.628 1.59 8.94 88547.21 0.000 .88.55 5500.00 83.05 8.39 253.95 254.10 0.00 0.00 170 5.628 1.55 8.73 89096.86 0.000 89.10 5500.00 83.60 8.20 261.65 261.80 0.00 0.00 175 5.628 1.52 8.54 89621.39 0.000 89.62 5500.00 84.12 8.01 269.34 269.50 0.00 0.00 180 5.628 1.48 8.34 90122.48, 0.000 90.12 5500.00 84.62 7.84 277.04 277.20 0.00 0.00 EXHIBIT `D' • MIAMI RIVERTOWN ANTICIPATED AVERAGE DAILY WATER CONSUMPTION IN GALLONS PER DAY (GPD) Residential 923 apartments @ 200 GPD/ unit Residential 62 townhouses @ 250 GPD/ unit Retail Stores 47,862 sq.ft(1) @ 5 GPD/ 100 sq. ft. Office 98,129 sq.ft. cr 10 GPD/ 100 sq. ft. Restaurant 149 seats(2) @ 50 GPD/ seat TOTAL 184,600 GPD = 15,500 GPD 2,393 GPD 9,813 GPD 7,450 GPD 219,756 GPD (1) dry uses (2) Assuming 70% of total restaurant area as dining room and 15sq. ft. per seat. • MIAMI RIVERTOWN ANTICIPATED AVERAGE DAILY SEWAGE FLOW IN GPD Average Daily Flow Sewage Flow = 219,756 GPD Average Flow = 152.61 GPM Peak Flow (1) = 534.13 GPM (1) Peak Flow uses a peaking factor of 3.5