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HomeMy WebLinkAboutMeridian Town Center - Big Al's Development - Storm Water Management - Engineering Drainage Report'w% ore TII1. LAND GROUP, INC. Meridian Town Center Big AI's Development Meridian, Idaho STORM WATER MANAGEMENT— ENGINEERING DRAINAGE REPORT OWNER CenterCal Meridian, LLC 7455 SW Bridgeport Rd, Ste. 205 Tigard, OR 97224 Ph: 503.968.8940 ENGINEER The Land Group, Inc. Jason Densmer, PE 462 East Shore Drive Eagle, Idaho 83616 Ph: 208.939.4041 Fax: 208.939.4445 Project No. 111049 Ar to r'im*piny a'Dsmp� Arch I',Cture Civil Erogif) ceritig •Golf curse ImfgaPion � Engineering *.Graj�nlc Comniueti�tYan msurveying 462 E. Snom Drive, Ste. 100, Eagle; Idaho 83616 • P 208.939.4041 P206 939.444-5- www thelandgrqupinc.com July 18, 2011 SITEDE The Meridian Town Center project is located at the northeast corner of the Fairview and Eagle road intersection in Meridian, Idaho. The entire project mately 9 -ac of rapproximately 90 -acres. The es. gig AI's phase of the development encompasses app proposed Power Center phase The property is currently undeveloped and bordered on the east by the under -construction north and west by the prop Kleiner Park (City of Meridian) and to the ill result in the construction of a parking lot and of Meridian Town Center. The project w building. SITE ASSESSMENT OF SOILS & SEASONAL GROUNDWATER GeoDesign, Inc. has prepared a geotechnical engineering report for the property, dated September 6, 2007 (copy attached as Appendix C). According to the study, groundwater was encountered at a depth of between 18.5 and 20 -ft below the ground surface. GeneraaleYststemslare des gnedsto penetrate theloverlying sfltla1nd ntrodu egstormwater m Dram g Y ates m discharge to the sand and gravel alluvium. The geotechnical testing of the percolation r percolationles per The drainage eerates between 6 an this strata indica which will to 8 -inches perhouro stemsafltersand medium, um, expected percolation rate for facility sizing. design, we have used an 8 -in per hour PEAK RUN-OFF RATE & SYSTEM SIZING 100 -YEAR EVENT AREAS (SEE DRAINAGE AREA EXHIBIT) The proposed storm drainage will sheet flow across asphalt and landscape areas to storm drain ed inlets. Storm water will pass through sand and grease traps prior to discharging to seepage facilities to allow the storm water to percolate into the existing sub soils. Provisions have been made to collect roof drains and pipe them into the seepage beds. The drainage systems have been designed to store the 100-year,1-hour endix Bevent (1.0 in/hr, time of concentration = 60 min.). The drainage calculations are shown in App Site Planning e Lrlut5capu Architecture Cvi! Engine ring - • I20 939'406n1tF 2Q 90y�ggq5. v,.u�w.thetandgr nupinc,carn° Surveying 452 E Share Drive, St, 100, Eagle, July 18, 2011 Appendix A Site Drainage Areas Site Ftanning atrzndscrrpa Arrhrtedxtru Gv ytrreuieg•Gnf ouuNrrlgat/nn&Englneeriug �6rophfLCar��nuni tion �Smveylrrg 462 E Shore Drive, Ste. 1001, Eagle, {deha S ii • P 208 930 1041 f 208 433.4445 + www_ thelanclgmupine.mm I II I_ i �' ' ran IVA � III L J 5 X1".!7 July 18, 2011 Appendix 6 Drainage Calculations 4,noinq Lot3d5ca}re Ai do ectw'e'o V �.3q reerinq -Golf use trrigution & Engi;7eering GrnpfnCf�i>tolPUCitG�rtioY� «Sur ueyinG} 462 E. Shore Drive, Ste. 100, Eagle, fdaho 23616 s P 208.939.4041 F 208.939.4441 - ww+n Ahelandgruapmc.crri Big Al's (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Overall Total Volume Volume of Volume ofID Size Provided Drain Rock SandArea1 152,062s.f. 1 10,812 c.f. 22,806 c.f. 2,534 c.f.Area 2 47,472 s.f. tRunoff 3,379 c.f. 7,128 c.f. 792 c.f.Area3 207,776s.f. 1 15,676 c.f. 33,066 cA. 3,674 c.f.Area 4 3,590 s.f. 267 c.f. 500 c.f. 63,500 c.f. 56 c.f. 7,056 0. Totals: 29,971 C.T. 30,133 c.f. 7/18/2011 Site Planning ShorenDr Drive, Suite h100t Eagle,'Idaho 83616 - P 08f 39 4041. Irrigation 208.939 4445 efwww the anGraphic dgroup no coSurveying Big Al's (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 1 Total A= 152,062 s.f. Pervious= s.f, `- - 0 10 Impervious= 152,062s.f. rj_R.S Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 6 68 cis 1100 = 3.10 in/hr Q100 = 9.20 cfs V25 = 5,348 c.f. V100 = 7,368 CA. 7/18/2011 Thompsons Rule (1" per hour) = 1.0 in/hr 000 Y1 Return Period, tura on 50 nein j Q= 2.97 cis (Q nt 64 min.) V = 10,771 c.f. L = 181 ft Vr = 22,806 c.f. Vv = 9,122 c.f. Vk= 1,689 c.f. - ( 9 10,812 c.f. Vtotal >_ V100? • k = 8.0 in/hr 4.4 hrs System Size W= 14 ft vrtumn "i, drain rock provided void volume provided percolation volume provi'Ied rotal siorcge volurbe provided byseepc;ye tied Time to Empty nercrllae ut, rnte an',e in drm;; rt`qutrerd si«rngrr".`otur,^ S&G Trap Check Vault Size= 1000 gal. Baffle Spacing= 3.0 ft Drainage Area 1A = 152,062 s.f. Max Flow = 2.97 cfs 0.25 fps D = 9.0 ft Site Planning - Landscape Architecture - Civil Engineering • Golf Course Irrigation & Engineering • Graphic Design , Surveying 462 E. Shore Drive, Suite 100 • Eagle, Idaho 83616 - P 208.939.4041 • F 208.939.4445 • www.thelandgroupinc.com Big Al's (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 2 Total A= 47,472 s.f. Pervious= s.t 0. Impervious = 47,472 s.f.- =-P` Weighted C= 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 2.08 cfs 1100 = 3.10 in/hr Q100 = 2,87 cfs V25 = 1,669 c.f. V100= 2,300c.f. 7/18/2011 Thompsons Rule (1" per hour) = 1.0 in/hr min.} Q = 0.93 cis i(i at 60 min.) V = 3,363 c.f. L= 99 ft Vr = 7,128 c.f. Vv = 2,851 c.f. Vk = 528 c.f. 3,379 CA, Vtotal > V100? • k = 8.0 in/hr 4.4 hrs Vault Size= 1000 gal. Baffle Spacing= 1.5 It Drainage Area 1A = 121,530 s.f. Max Flaw = 2.37 cfs 0.40 fps System Size W=8ft D=Mft volurne of drain toLk provided void volume provided percoiorioz, voturne provided roto) srorug- volume pr";vlded by seepage bed Time to Empty pe,rololion ra#e t Me to drolr; require sir<r ge vr,(urr,=. S&G Trap Check OKAY site Planning - Landscape Architecture - Civil Engineering • Golf Course Irrigation & Engineering • Graphic Design - Surveying 462 E. Shore Drive, Suite 100 • Eagle, Idaho 83616 - P 208.939.4041 • F 208.939.4445 • www.thelandgroupinc.com Big Al's (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 3 Total A= 207,776 s.f. Pervious= s.f. Impervious = 207,776 s.f. C = 0,90 Weighted C = 0.90 Tc= 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 9.66 ds 1100 = 3.10 in/hr Q100 = 13.31 cfs V25 = 7,737 c.f. V100 = 10,660 CA. 7/18/2011 Thompsons Rule (1" per hour) = 1.0 in/hr 1200-y Rc'trrtr r'eriod, Duration - 60 min-�• Q = 4.29 cfs (a ai 50 mitt.) V = 15,583 c.f. L= 167 ft Vr= 33,0660. VV = 13,226 c.f. Vk.= 2,449 c.f. 15,676 c.f. Vtotal >_ V100? • k = 8.0 in/hr 4.4 hrs Vault Size= 1000 gal. Baffle Spacing= 1.5 ft Drainage Area 1A= 53,273 s.f. Max Flow = 1.10 cfs 0.18 fps System Size W=22ft D=9.0ft volume of drain rock provided void volume provided percolation volurne provided totot storage vra'ome provided by seepage bed Time to Empty percoiation rate tiroe io dra=in required srorcge vaium S&G Trap Check OKAY IV Site Planning - Landscape Architecture • Civil Engineering • Golf Course Irrigation & Engineering • Graphic Design - Surveying 462 E. Shore Drive, Suite 100 , Eagle, Idaho 83616 - P 208.939.4041 • F 208.939.4445 • www.thelandgroupinc.com Big Al's (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 4 Total A= 3,590 s.f. Pervious= s.f. C= 0.20 Impervious = 3,590 s.f. 0. P5 Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 0 1 cts 1100 = 3.10 in/hr Q100 = 0.22 cfs V25 = 126 c.f. V100 = 174 c.f. 7/18/2011 Thompsons Rule (1" per hour) = 1.0 in/hr (100 yrReturrr Period, Durollon = 60 min.) Q=0.07cfs (03nr60rnin.j V= 254 c.f. L= 20 ft Vr = 500 c.f. Vv = 200 c.f. Vk = 67 c.f. �M 267 c.f. Vtotal >_ V100? • System Size W=5ft D=5.0It volume andomruck.orow cd void vrfume provided petro(ation volunie provided total storoge uolu,me provided ,'ry se-=;pcj0" br—d Time to Empty k=8.0in/hr percolr ori=r;te 2.6 hers orae to dnair, r('gL+ir€o -'tong e> volume S&G Trap Check Vault Size = 1000 gal. Baffle Spacing = 1.5 ft Drainage Area 1A = 109,965 s.f. Max Flow = 2.1.5 cfs 0.36 fps Ok.1l" Site Planning -Landscape Architecture • Civil. Engineering -Golf Course Irrigation & Engineering � Graphic Design •Surveying 462 E. Shore Drive, Suite 100 • Eagle, Idaho 83626 • P 208.939.4041 - F 208.939.4445 • www.thelandgroupinc.com 'I'M F 1.ANI) e A -P, IN4— Meridian Town Center Village Center Development Meridian, Idaho STORM WATER MANAGEMENT— ENGINEERING DRAINAGE REPORT OWNER CenterCal Meridian, LLC 7455 SW Bridgeport Rd, Ste. 205 Tigard, OR 97224 Ph: 503.968.8940 ENGINEER The Land Group, Inc. Jason Densmer, PE 462 East Shore Drive Eagle, Idaho 83616 Ph: 208.939.4041 Fax: 208.939.4445 Project No. 111049 0 May 22, 2012 SITE DESCRIPTION The Meridian Town Center project is located at the northeast corner of the Fairview and Eagle road intersection in Meridian, Idaho. The entire project consists of approximately 90 -acres. The Village Center phase of the development encompasses approximately 65 -acres. The property is currently undeveloped and bordered on the east by Kleiner Park (City of Meridian), to the north by the Power Center Phase of Meridian Town Center, to the south by Fairview Avenue and to the west by Eagle Road. The project will result in the construction of a lifestyle shopping center with a broad selection of apparel, home goods, entertainment and restaurant opportunities. This report analyzes and provides recommended drainage facilities to serve the needs of the project. Construction documents of the improvements have been prepared and show final details necessary for construction. SITE ASSESSMENT OF SOILS & SEASONAL GROUNDWATER GeoDesign, Inc. has prepared a geotechnical engineering report for the property, dated September 6, 2007 (copy attached as Appendix Q. According to the study, groundwater was encountered at a depth of between 18.5 and 20 -ft below the ground surface. Generally, the soil profile consists of a thin mantle of silt overlying sand and gravel alluvium. Drainage systems are designed to penetrate the overlying silt and introduce storm water discharge to the sand and gravel alluvium. The geotechnical testing of the percolation rates in this strata indicate expected infiltration rates between 16 and 63 -inches per hour. The drainage systems include a filter sand medium, which will limit percolation to 8 -inches per hour. For design, we have used an 8 -in per hour expected percolation rate forfacility sizing. PEAK RUN-OFF RATE & SYSTEM SIZING 100 -YEAR EVENTAREAS (SEE DRAINAGE AREA EXHIBIT) The proposed storm drainage will sheet flow across asphalt and landscape areas to storm drain inlets. Storm water will pass through sand and grease traps prior to discharging to seepage bed facilities to allow the storm water to percolate into the existing sub soils. Provisions have been made to collect roof drains and pipe them into the seepage beds. The drainage systems have been designed to store the 100 -year, 1 -hour event (1.0 in/hr, time of concentration = 60 min.). The drainage calculations are shown in Appendix B. Appendix A Site Drainage Areas If May 22, 2012 May 22, 2012 Appendix B Drainage Calculations Ir Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 1(Bldg AG -100) Total A= 9,450 s.f. Pervious = s.f. _ Impervious = 9,450 s.f. Weighted C = 1.00 Tc= 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 0.49 cfs 1100 = 3.10 in/hr Q100 = 0.67 cfs V25 = 391 c.f. V100 = 539 c.f. Thompsons Rule (1" per hour) I= 1.0 in/hr Q = 0.22 cfs V = 788 c.f. System Size L= 21ft W= 9ft Vr = 1,701 c.f. Vv = 680 c.f. Vk = 126 c.f. ZZ806c.f, OKAY Time to Empty k = 8.0 in/hr M 4.3 hr> S&G Trap Check Vault Size = 01dcastle New 1000 gal. Number of units= 11 Baffle Area/unit = 17.08 s.f. Drainage Area 1A = 19,450 s.f. Max Flow = 0.67 cfs ��rovflumiiii 0.09 fps OKAY 5/22/2012 D = 9.0 ft Site Planning - Landscape Architecture - Civil Engineering - Golf Course Irrigation & Engineering - Graphic Design - Surveying 462 E. Shore Drive, Suite 100 - Eagle, Idaho 83616 - P 208.939.4041 - F 208.939.4445 - www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 2 Total A= 80,981 s.f. Pervious = s.f. Impervious = 80,981 s.f. Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 3.56 cfs 1100 = 3.10 in/hr Q100 = 4.90 cfs V25 = 2,848 c.f. V100 = 3,924 c.f. Thompsons Rule (1" per hour) = 1.0 in/hr Q = 1.58 cfs V = 5,736 c.f. L= 90ft Vr = 12,150 c.f. Vv = 4,860 c.f. Vk = 900 0. 5,760 c.f. Vtotal >_ V100? • k = 8.0 in/hr 4.4 hrs System Size W=15ft Time to Empty 5/22/2012 D = 9.0 ft Site Planning - Landscape Architecture - Civil Engineering - Golf Course Irrigation & Engineering - Graphic Design • Surveying 462 E. Shore Drive, Suite 100 - Eagle, Idaho 93616 - P 208.939.4041 - F 208.939.4445 • www.thelandgroupinc.com S&G Trap Check Vault Size = Old_c_astle New 1000 gal. Number of units= 2 Baffle Area/unit = _ I,7.08 s.f. r Drainage Area lA = 80,981 s.f. Max Flow= 4.90 cfs 0.35 fps OK yY 5/22/2012 D = 9.0 ft Site Planning - Landscape Architecture - Civil Engineering - Golf Course Irrigation & Engineering - Graphic Design • Surveying 462 E. Shore Drive, Suite 100 - Eagle, Idaho 93616 - P 208.939.4041 - F 208.939.4445 • www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 3 Total A= 179,312 s.f. Pervious = s.f. Impervious = 179,312 s.f. Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 7.87 cfs 1100 = 3.10 in/hr Q100 = 10.85 cfs V25 = 6,306 0. V100 = 8,688 c.f. 5/22/2012 Thompsons Rule (1" per hour) I = 1.0 in/hr Q=3.50cfs 4Orr30min.) V = 12,701 c.f. L = 200 ft Vr = 27,000 c.f. Vv = 10,800 c.f. Vk = 2,000 c.f. 12,800 c.f. Vtotal ? V100? • k= 8.0in/hr 4.3 hrs System Size W=15ft void vchime pros;d�J �ercogSicn s'c,''u':m� crc✓.J�,.; total stflr:�ge �'ai�ime provit,'=1 by sz= �� y - _ Time to Empty S&G Trap Check Vault Size = Oldcastle New 1000 gal. Number of units = 14 _ Baffle Area/unit = 7.08 s.f. Drainage Area 1A = 1179,312 s.f. Max Flow = 10.85 cfs 0.38 fps Cl[i.\l' D = 9.0 ft Site Planning - Landscape Architecture - Civil Engineering - Golf Course Irrigation & Engineering • Graphic Design - Surveying 462 E. Shore Drive, Suite 100 • Eagle, Idaho 83616 - P 208.939.4041 • F 208.939.4445 - www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 4 Total A = 83,445 s.f. Pervious = s.f. Impervious = 83,445 s.f. Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr 1100 = 3.10 in/hr V25 = 2,935 c.f. V100 = 4,043 c.f. I= 1.0 in/hr Q = 1.63 cfs V = 5,911 c.f. L=93ft Vr = 12,555 c.f. Vv = 5,022 c.f. Vk = 930 c.f. 5,952 c.f. OKAY k = 8.0 in/hr 4.3 hrs Q25 = 3.66 cfs Q100 = 5.05 cfs Thompsons Rule (1" per hour) LJOyt t�irn Q of 60 min.) System Size W=15ft 5/22/2012 void volurr= u _ oercolotio,a v_;u;-_ o; wid��l ,,`sii,torr vo :; ,a iavirle f b s2epi;ge he Time to Empty S&G Trap Check Vault Size = j0ldcastle New 1000 gal. Number of units= '2 Baffle Area/unit = 7.08 s.f. Drainage Area 1A = 83,445 s.f. J Max F�loww= 5.05 cfs �CGfL"ilrl'LLlii 0.36 fps 0[LjI D= 9.0 ft Site Planning - Landscape Architecture Civil Engineering - Golf Course Irrigation & Engineering - Graphic Design - Surveying 462 E. Shore Drive, Suite 100 - Eagle, Idaho 83616 - P 208.939.4041 - F 208.939.4445 • www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 5 Total A= 148,997 s.f. Pervious = s.f. Impervious = 148,997 s.f. Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 6.54 cfs 1100 = 3.10 in/hr Q100 = 9.01 cfs V25 = 5,240 c.f. V100= 7,219 c.f. Thompsons Rule (1" per hour) 1 = 1.0 in/hr Q = 2.91 cfs V = 10,554 c.f. System Size 5/22/2012 L= 191ft W= 13ft Vr= 22,347 c.f. voiu, , - Vv = 8,939 c.f. void vo;ume Orwida Vk = 1,655 c.f. perccla:'oa ";fume j' 10,594 c.f. total ul,ime oro,, Time to Empty k = 8.0 in/hr- f 4.4 hrs S&G Trap Check Vault Size = Oldcastle New 1000 gal. Number of units= 3 - Baffle Area/unit = I7.08 s.f. Drainage Area 1A = 1148,997 s.f. Max Flow= 9.01 cfs 0.42 fps OKAY Site Planning - Landscape Architecture - Civil Engineering - Golf Course Irrigation & Engineering • Graphic Design - Surveying 462 E. Shore Drive, Suite 100 • Eagle, Idaho 83616 - P 208.939.4041 - F 208.939.4445 • www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 6 Total A= 267,835 s.f. Pervious = s.f. Impervious = 267,835 s.f. Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 11.76 cfs 1100 = 3.10 in/hr Q100 = 16.20 cfs V25 = 9,419 c.f. V100 = 12,978 c.f. Thompsons Rule (1" per hour) I= 1.0 in/hr Q = 5.23 cfs V = 18,972 c.f. L= 343 ft Vr= 40,131 c.f. Vv = 16,052 c.f. Vk = 2,973 c.f. 19,025 U. OKAY k = 8.0 in/hr 4.4 hrs 5/22/2012 Time to Empty D = 9.0 ft Site Planning -Landscape Architecture -Civil Engineering -Golf Course Irrigation & Engineering Graphic Design • Surveying 462 E. Shore Drive, Suite 100 • Eagle, Idaho 83616 - P 208.939.4041 - F 208.939.4445 • www.thelandgroupinc.com S&G Trap Check Vault Size = Oldcastle New 1000 gal. Number of units= 5 Baffle Area/unit = ',7.08 s.f. Drainage Area 1A = ,267,835 s.f. Max Flow = 16.20 cfs 0.46 fps OKAY D = 9.0 ft Site Planning -Landscape Architecture -Civil Engineering -Golf Course Irrigation & Engineering Graphic Design • Surveying 462 E. Shore Drive, Suite 100 • Eagle, Idaho 83616 - P 208.939.4041 - F 208.939.4445 • www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 7 Total A= 64,511 s.f. Pervious = s.f. Impervious = 64,511 s.f. Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 2.83 cfs 1100 = 3.10 in/hr Q100 = 3.90 cfs V25 = 2,269 c.f. V100= 3,126 c.f. I = 1.0 in/hr Q = 1.26 cfs V = 4,570 c.f. L= 135ft Vr = 9,720 c.f. Vv = 3,888 c.f. Vk = 720 c.f. 4,608 c.f. Vtota 12 V 100? k = 8.0 in/hr 4.3 hrs Thompsons Rule (1" per hour) System Size W=8ft ,_id volume provided volume provi.':' 5/22/2012 , age vociume pry,, _ - Time to Empty S&G Trap Check Vault Size = IOldcastle New 1000 gal. Number of units= 12 Baffle Area/unit = 17.08 s.f. Drainage Area 1A = 164,511 s.f. Max Flow = 3.90 cfs 0.28 fps OKAY D = 9.0 ft Site Planning - Landscape Architecture • Civil Engineering - Golf Course Irrigation & Engineering - Graphic Design • Surveying 462 E. Shore Drive, Suite 100 • Eagle, Idaho 83616 - P 208.939.4041 - F 208.939.4445 • www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 8 Total A = 44,450 s.f. Pervious = s.f. Impervious = 44,450 s.f. Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 1.95 cfs 1100 = 3.10 in/hr Q100 = 2.69 cfs V25 = 1,563 c.f. V100 = 2,154 c.f. Thompsons Rule (1" per hour) 1 = 1.0 in/hr Q = 0.87 cfs V = 3,149 c.f. System Size L= 74ft W = loft Vr = 6,660 c.f. Vv = 2,664 0. Vk = 493 0. 3,157 c.f. OKAY Time to Empty k = 8.0 in/hr 4.4 hrs S&G Trap Check Vault Size = 'Oldcastle New 1000 gal. Number of units= 2 Baffle Area/unit = 7.08 s.f. Drainage Area lA ='44,450 s.f. Max Flow = 2.69 cf; �- i 0.19 fps OKAY 5/22/2012 D = 9.0 ft Site Planning - Landscape Architecture - Civil Engineering • Golf Course Irrigation & Engineering • Graphic Design • Surveying 462 E. Shore Drive, Suite 100 - Eagle, Idaho 83616 • P 208.939.4041 - F 208.939.4445 - www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 9 Total A= 299,250 s.f. Pervious = s.f. Impervious= 299,250 s.f. Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 13.14 cfs 1100 = 3.10 in/hr Q100 = 18.10 cfs V25 = 10,524 c.f. V100 = 14,500 c.f. 5/22/2012 Thompsons Rule (1" per hour) = 1.0 in/hr 10p -,r C" Duro _., _ :. nin Q=5.84 cfs (Q 7t 50 M. in.) V = 21,197 c.f. System Size L= 178ft W= 28ft D= 9.0 ft Vr = 44,856 c.f.'! -I .: ; " , - '-1, _ , Vv = 17,942 c.f. void volume ,orwrded Vk = 3,323 c.f. perCjkJ""On volume provided 21,265 c.f. otcil storage volume pro'•,ided by ��=,o�u�e bed OKAY Time to Empty k = 8.0 in/hr 4.4 hrs S&G Trap Check Vault Size = Oldcastle New 1000 gal_ (2-1500 gal.) Number of units= 15 Baffle Area/unit = 7.08_s.f. Drainage Area 1A= ',299,250 s.f. Max Flow= 18.10 cfs 0.46 fps OKAT Site Planning - Landscape Architecture • Civil Engineering • Golf Course Irrigation & Engineering • Graphic Design • Surveying 462 E. Shore Drive, Suite 100 • Eagle, Idaho 83616 • P 208.939.4041 • F 208.939.4445 • www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 10 Total A= 326,703 s.f. Pervious = s.f. Impervious = 326,703 s.f. Weighted C = 0.85 Tc= 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 14.34 cfs 1100 = 3.10 in/hr Q100 = 19.76 cfs V25 = 11,489 c.f. V100 = 15,830 c.f. Thompsons Rule (1" per hour) I= 1.0 in/hr j100 -Yr run Q = 6.38 cfs rQ or 60 min.) V = 23,141 c.f. System Size 5/22/2012 L= 320ft W= 17ft D= 9.0 ft Vr = 48,960 c.f. il� _ : J, oc;< provij-d Vv = 19,584 c.f. void volume provided Vk = 3,627 c.f. percolation volume provided 23,211 c.f. totoi,torage volume orovAded by s22voga fled 0 MT9 Time to Empty k = 8.0 in/hr IM4.4 hrs S&G Trap Check Vault Size = IOldcastle New 10_00 gal._ Number of units = 6 _ Baffle Area/unit = 7.080. Drainage Area 1A = 326,703 s.f. Max Flow = 19.76 cfs 0.47 fps OK a1" Site Planning - Landscape Architecture - Civil Engineering - Golf Course Irrigation & Engineering - Graphic Design - Surveying 462 E. Shore Drive, Suite 100 - Eagle, Idaho 83616 • P 208.939.4041 - F 208.939.4445 - www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 11 (Bldg AD -100) Total A= 7,991 s.f. Pervious = s.f. Impervious = 7,991 s.f. Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 0.35 cfs 1100 = 3.10 in/hr Q100 = 0.48 cfs V25 = 281 c.f. V100 = 387 c.f. Thompsons Rule (1" per hour) 1 = 1.O in/hr Q = 0.16 cfs V = 566 c.f. System Size L=19ft W=7ft Vr = 1,197 c.f. Vv = 479 c.f. � Vk = 89 c.f. 'ZZ 567 c.f. Vtotal >_ V100? • Time to Empty k = 8.O in/hr 4.4 In rS S&G Trap Check Vault Size = Oldcastle New 1000 gal. Number of units= 1 Baffle Area/unit = 1117.08 s.f. Drainage Area 1A = 17,991 s.f. Max Flow= 0.48 cfs LVA 0.07 fps OKAY 5/22/2012 D = 9.0 ft Site Planning - Landscape Architecture - Civil Engineering - Golf Course Irrigation & Engineering • Graphic Design - Surveying 462 E. Shore Drive, Suite 100 - Eagle, Idaho 83616 • P 208.939.4041 • F 208.939.4445 • www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 12 (Bldg AB -100) Total A= 10,225 s.f. Pervious = s.f. Impervious = 10,225 s.f. Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 0.45 cfs 1100 = 3.10 in/hr Q100 = 0.62 cfs V25 = 360 0. V100 = 495 0. I= 1.0 in/hr Q = 0.20 cfs V = 724 0. L= 25ft Vr= 1,575 0. Vv = 630 c.f. Vk = 117 0. M 747 U. Vtotal >_ V100? • Thompsons Rule (1" per hour) System Size W=7ft Time to Empty k = 8.0 in/hr 4.2 hrs S&G Trap Check Vault Size = 'Oldcastle New 1_000_ gal. Number of units= 1 Baffle Area/unit = '7.08s f. Drainage Area 1A = 10,225 s.f. Max Flow= 0.62 cfs ®' 0.09 fps Oh 1 5/22/2012 ON •11 Site Planning - Landscape Architecture - Civil Engineering • Golf Course Irrigation & Engineering - Graphic Design - Surveying 462 E. Shore Drive, Suite 100 - Eagle, Idaho 83616 • P 208.939.4041 • F 208.939.4445 • www.thelandgroupinc.com Village Center (PN 111049) Storm Drainage Calculations Drainage Area Characteristics: Area 13 Total A= 128,100 s.f. Pervious = s.f. Impervious= 128,100 s.f. Weighted C = 0.85 Tc = 10 min. Rational Method/Triangular Hydrograph 125 = 2.25 in/hr Q25 = 5.62 cfs 1100 = 3.10 in/hr Q100 = 7.75 cfs V25 = 4,505 c.f. V100 = 6,207 c.f. Thompsons Rule (1" per hour) 1 = 1.0 in/hr Q = 2.50 cfs V = 9,074 c.f. System Size L= 89 ft W= 24 ft Vr = 19,224 c.f. Vv = 7,690 c.f. Vk = 1,424 0. 9,114 c.f. 7*54-lffli Time to Empty k = 8.0 in/hr 4.4 hrs S&G Trap Check Vault Oldcastle New 1000 gal. - Number of units -'3 Baffle Area/unit = 7.08 s.f. Drainage Area 1A = 128,100 s.f. Max Flow = 7.75 cfs 0.36 fps OKAY 5/22/2012 lilliff,", Site Planning - Landscape Architecture - Civil Engineering - Golf Course Irrigation & Engineering - Graphic Design - Surveying 462 E. Shore Drive, Suite 100 - Eagle, Idaho 83616 - P 208.939.4041 - F 208.939.4445 • www.thelandgroupinc.com May 22, 2012 Appendix C Geotechnical Report for Reference cz O e= N 0) cz W Area 9,450 Fairview Avenue 7,991 sf 10,225 sf Onsite Storm Drainage Tributary Areas 4.t N0.: App A a� O co C O C: ~ C$)-0 05 i _CC G C� G u E E V/ (D 0) ^C W (Zr E `V O 0 E T O O U � � C OD U 's TILE LAND GROUP Pmoct No.: 11101! 4.t N0.: App A