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HomeMy WebLinkAboutDrainage Reports - 05/16/2013IGrNey-Hom IMM_ ari oaates, Inc. September 191", 2012 Glen. Schlueter City of Fort Collins Stormwater Engineering 281 North College Avenue Fort Collins, Colorado 80522 Re: Discount Tire at North College Marketplace Drainage Compliance Letter City of Ft. Collins rov , lans Approved By. Date The intent of this letter to provide drainage analysis for the development of Lot 7 within the North College Marketplace located at the northeast corner of East Willox Lane and North College Avenue within the City of Fort Collins, Colorado. Following is a brief summary of the proposed development. Existing Site Conditions The existing site is currently vacant and sparsely vegetated. The proposed overlot graded pad varies in elevation from a high of ±4,985 feet to a low of ±4,982 feet. The majority of the existing pad drains easterly in direction at average slopes of ±1.25% where.it is conveyed via curb and gutter to the existing North College Marketplace storm sewer system. Adjacent land uses consist of the following: o North: Private Drive o East: ' Commercial Development (King Soopers) o South: Commercial Development (Pobre Pancho's) o West: North College Avenue Anticipated Developed Conditions This site is included as a part of the approved Drainage and Erosion Control Report for the North College Marketplace Final Development Plan, ("Master Drainage Report"), prepared by Ayres Associates dated August, 2009. As outlined within the Master Drainage Report, developed runoff from this site is mostly a part of drainage Basin P9. The runoff for Basin P9 is conveyed overland to a porous landscape detention island. During the minor and major events stormwater enters a Type C inlet and is.conveyed to Water Quality and Detention Pond. Anticipated site runoff characteristics for Lot 7, as outlined within the Master Drainage Report, consist of the following: o Area = 1.19 Acres O IcomposrE = 89 % o Cs = 0.82 O Clo = 0.82 o Cloo = 0.88 Developed Conditions The current proposal for development of the site consists of a ±6,947 square foot retail sales and vehicle service building with associated parking and landscape ■ Suite 200 990 South Broadway Denver, Colorado 80209 ■ TEL 303 228 2300 Kimley-Hom and Associates, Inc. improvements. Proposed grading for the site generally follows the anticipated drainage patterns as approved within the Master Drainage Report. The proposed drainage concept consists of sheet flow easterly across the site. The sheet flow will be conveyed via curb and gutter to existing stormwater facilities offsite and downstream. Developed Site runoff characteristics consist of the following: o Area = 1.19 Acres O . IcOMPO51TE = 67% o C5 = 0.66 o CID = 0.66 o CIDo = 0.73 Conclusion As identified above, the composite imperviousness of the developed site results in a reduction from the anticipated developed site imperviousness within the approved Master Drainage Report; and therefore, complies with the designs anticipated within the Master Drainage Report. It is our conclusion that the site substantially complies with the design and assumptions within the Master Drainage Report. Please consider this letter as the final storm water analysis for the proposed development of Lot 7 within the North . College Marketplace development. Should you have any questions or concerns please do not hesitate to contact me at 303.228.2300. Sincerely, Kimley-Horn and Associates, Inc. Gabe Krell, PE, LEED AP Attachments: Master Drainage Report References Kday-Hom C m and Associates, Inc. Appendix A Master Drainage Report References I II i P1 � 3 38 P26 20 � OFFSITE ws "I P24 IT \� cj P36 'P0 10 90 P4 A Ps 1 I a, 90 At t 1 I r 3u 1_ / P35 s4 90 1 _ i SOUT„ PLD 9. . ' 31 ti. t �P14 P13 t P21 I v 1 .4 91 1 D 16 30 P10 - - t. 23 90 i r GAS STATION* ° P 12 , P2728 8 * GAS STATION PROVIDES OWN WQ TREATMENT AND WETLAND POND ACTS LIKE WQ FOR POND ITSELF I PROVIDED WQ BOUNDARY �1 WQ POND �I 2;� P19 87 3 7 ;a loa o . 7 WETLAND / DETENTION POND PROVIDES OWN TREATMENT �a��.J P� 5J� --- '71' x■IIWL - P a 30 60 120 SCALE � LEGEND EXISTING MAJOR CONTOURS EXISTING MINOR CONTOURS PROPOSED MAJOR CONTOUR PROPOSED MINOR CONTOUR im PROPOSED STORM P6 PROPOSED BASIN AREA (AC)' n . PERCENT IMPERVIOUS (u) FLOW DIRECTION A. DESIGN POINT - • - BASIN BOUNDARY BASIN FLOW SUMMARY BASIN Q,wyR Q,OYR P1 1.4 0.7 0.1 P3 7.1 3.1 P4 3.1 1.5 7.9 1.9 8.5 3.2 P7 31.5 14.8 ps 83 3.7 27.1 12.3 PIC 3.2 1.5 P11 11.8 5.8 1 4.9 2.0 P13 b.e 1 23 Pi4 4.4 2.1 i 2.6 0.8 8 .0 0.5 P7 2.3 1.1 1 9.1 3.7 19 5.5 0.9 1.6 0.8 2A 1.1 4.0 1.8 8.1 2.7 4 0.3 0.1 4 ..8 21.6 7.3 1.0 3.9 18 1.3 0.6 2 2 0.4 330.4 116.4 t 0.0 9.3 P33 0.5 1 0.1 5.1 2.5 1.0 0.5 D.o3 0.02 II P29 s z • • DETENTION POND SUMMARY lJ • • ,I OFFSITE ` 100 YR 10 VR ;Y VOL (A ) 8.28 2.04 ♦ w a97a.2o a972se • • BOTTOM OF POND. 4971 / INVERT OUT .4971.00 TOP OF POND- 4976 i • •` 1 DOYR RELEASE RATE. 4.93 CFS I • ALLOWED 100YR RELEASE RATE. 5.01 CFS • . WATER QUALITY SUMMARY FF WO POND T VOLUME 1 VOLUME REO • WO POND 0.76 AC.FT 0A6 AC•FT PLD AREA AREA REO I SOUTH M1760 FT2 44FO- I NORT14 1 5611 FTZ 1352Z-71 SS ' P32 PROPOSED sp 35 DRAINAGE ' f OFFSITE BASINS FIGURE 3.4 I AlIRES Is " -"-"- ASSOCIATES • North College Marketplace PROPOSED SWMM PARAMETER INPUT Design Englneea, L. Chalfant Design Firm: Ayres AssaNates Project Number: 32-1322.00 Dana: August 11. 2009 DESIGN CRITERIA: Urban Storm Dminege Cmerta Manual by Urban Drainage and Flood Control District, June 2D01 City of Fort Collin Smrm Drainage Criteria, January 1997 In, Impervious valueS from Table R03 and C Values obtained IrOm Table 3-3 0 the City Of Fort Collins Storm Drainage Criteria for HydrOlogit Sall Classilicaaon C C VALUE CS CIO C. %Impervious Paved 0.90 0.90 0.95 100.016 Lawns 0.15 0.15 0.25 0.0% poufs 0.90 0.90 0.95 90.0% Gravel O,so 0S0 OSO 40.01: Su0-oasln Designation Pl PP *Ana Aso An., A. I Al ASIl COMPOl •Perunl Impervloua 2•A TA 00!i 91w a6!i on: "1; ba:: 6%: Overland Length (It) 75 ]b 2tJ mo 60 50 110 241 Joe 150 SO SO t21 50 60 m 19 135 300 49 Max Length 300(fl) 75 7a m3 w 50 So 110 Nt ISO "a W 50 tti SD tip 70 19 In 300 49 al Fab MI zz n 3m 67 A 2m 3m 60 15D 60 50 6 12 Ch6nnelilAtl Length (11) 0 D a 260 160 Joe 450 26 o 64 360 274 I0) 300 NO m SS 240 350 156 114 m IS 24 760 260 38d 326 0 mbo ISO 630 25 376 e3 t5 Flawpam Length (Il) 76 75 wa sod 200 Jso sad x6T Dm 2N 4ta 324 2m 3m JOB 1W 104 3 66 IN 203 l95 :qt 310 49 70 5SO 4$3 35S m0 26W IN ea0 >6 a26 of 2T Overall Slope -so O.W.: a6ati t.6mi IM% tA0!: 1.00!: 2.00n lA0!: xSM: 1AOv. lore!: olu)% tAO: ISSL' IWA 2. 1,Sp% 'Ad, Man, 0-105, 'All 1.00•w 1.00!: 1A0r. tAY.: 2AOn afr.. OAO•: aAOY. 2S0%' 1A0!: 0.50!: 1A0!: 1.W!: OAC. 1A0•w tAr: Overland Flow Width •Lw (ModswMM) (11) in 7e- I'd my N1 e6o ltal 16a 4p9 91 1a12 ftl t76 ]Ba ZM 62 Sm =4 562 AS ltt a6 1m se 4>96 P+s iD9 m1 97 7127 3O0 dell 62 NS » Jag Notes 011.it. 6a.6,01 p114M 9ooF NemO pool cblbp•Ars.� COMp•Aranw Celle Av4rw PardN0 Lot pod P•rele,p bl to wulh Pl9 Ga. Aaiun El bwbpn.,a WAa. Ler+e Pua6q W-lo avbM Yti Mhfitl K-4q 5'4wp.r4 SPNhoi fil eeee.n hueFMm Troeap.ap Maa MIfeW pin, Salop W.tb,O.per,d qad pod pool pool pml?hinnm P•r6N9 Mte North PLD E>i.(v,p WW,tao WAOi lade Wiao. Sarre O113e. ue. tolMaulallM porn 011 Obo aru mnh of laW En11an40 ollof Wibz 011.a. uIl to wi11o3I91'oU.wrr d041 SoaM mMddrdd'np Wab. t4er Rad•A.wtvaq doll pool -Frain Enlr.ne. - Weler OIro91Y Provitled North Porous LandmCa Detention NOrlh POrOtr6 LO0d9Ca Detention water 000lil Pond Water OuaO Pond Wafer OU86 Pend Waiar Oual Pond War Ouall POM Water Weill Poltd - Soulh Parwm L8ntl5Ce BDCllmllon G095181100•le treat 6nell0 Water Quality Pond Water Quality Pond Water Quality Pond WdSEr Oltar Pantl Water Qua Pond Wafer Ouali Pend Wafer Quality Pond Water Waal Pend Wellantl9 WalerDwa P00tl Water Ouar Pond Water OUar Pantl Water Wal Ports water Wall Pond - North Porous LaMSta DGIemiOn Wellaml9 Wafer QUdb Pond WdICr OuaD Pone Wetlands -TO be imdletl 0115110 When tlCV61 0 PlevioUSl Imdlad South Porous Landsca Detention io be treated OnAle when d8VEl0 Water Wall P011tl Exail tleP010Prilerll Water OuaO Pond Wafer Ouab Pond DIMr X X X X X % % N PLD a a X S PLD X % WO Pond Y X % X % X X % X X X X X % X X X X X X X X X X 100Yr Flaw (did) 1A 0.7 7.1 3.1 3.9 6.5 31S 8.3 27.1 32 11J7 4.9 4.8 4.4 2,6 1.0 2.3 8.1 SS 1.6 1.6 4.0 6.1 0.3 44.8 7.3 3.9 1.3 2.2 330.4 4.4 30.0 0.5 5.1 1.0 0,03 1Dyr Flow (CIO) 0.2 0.1 3.1 1.6 1.9 32 14,8 3.7 123 1.$ 5.8 2.0 2.3 2.1 0.8 0.5 1,1 3.7 0.9 0.6 0.8 1.6 2.7 0.1 21.6 1.0 1.0 0.6 0.4 118.4 20 9.3 0.1 0.1 0,5 0,02 (oeras) 013 01J (at,.(1) linMir bN0 (was) 0.01 000 ("To.) 025 O.t9 (auas) 000 000 07a (=as) 0A0 0.00 000 Ca 0.1> O.V O.m oAs CIO 0.17 0.17 0.90 ode Op Ctae 02a 030 OAS ova am oA3 P3 O18 32026 0.00 00D Pt, a39 1706 oNo om 4w 40O P6 a39 ti0x6 OJ> 00P 000 .0.00 Ode P6 Ilan tam oAa o0x Sao 000 ode ode P7 ]19 W944 34t Oq Oa2 0.00 oat a" am Pa OM A960 0.00 doe O.e) OAO n9a OAO OAS Po 261 iZZWO tat 03O 021 000 odx OJtl OM P10 P11 P12 Oat fitOS3 OSJ 14W 61591 231a1 old am Oat ON 002 021 D14 000 000 Ode ON O.OD 0.0 "1 Oat Od4 a" 0.61 0.61 O.H OAS 0.44 469 089 0.D2 N!: 91l: 61% 91!: Om!: 33% 10Y.: 100% P13 040 N217 Ou ON 0.00 OAO PIS 0.4 l0]90 O.q 0,03 O.00 0A0 p,pT OA7 Pis P10 Oat 0+0 13]17 q09 0.11 0.10 021 0.ad OAD 0.00 0-00 000 a4a OAO 0.4D OAO 0.40 OAS P17 02J t0235 023 000 OAD 0. DAD a,9e OAS Pia P20 100 30> 41214 1605M 0.69 0.0< 01 J4> OAO 0A0 OA0 0.15 am a.tl OA6 0.1T an 0.n all T: P2d 0.16 J1W 000 0.00 0.16 0.00 0A0 Om 0A5 9p.: P21 PT2 P24 024 Om 10m1 10630 2700e ONO 0.00 o.oO O00 0.00 ado 024 OA 4u am e00 0A0 o0o 0.06 0.06 O.OD am a.90 Odd 0A0 O.Ta O.I7 0.76 a." 0.00 odd 0.70 OAd 0.1] 0.75 a.T4 0A5 0A5 am 0A5 o.N 016 0A1 Ode Sll SO!: W..: 90!: n!: 3•w a0. >0•.i Y,: 431i t5!: e!: .1 door 90!: 81 t63 nt 2P 4l J00 S7 30 m0 300 60 tap tip 50 e 1P on 000 Ks P26 ISMS amcoo O.fie P27 2 U8373 TloSq 600 no -no- P2i M am 0]i am O.00 0.00 Pm J64S SON 5a2p 0.+1 003 0.00 0A0 aTt Pm 19a26 001 O.M 000 Om 0.17 0.17 a" P30 21D0032 22.09 270 000 Oto OAO OA9 047 Pot PR P33 00> 4AI 19506 1T1t7>.60 3109 tt24t 19e 035 lA2 0.01 0.49 o00 ,0.00 0.10 2W p.OT 003 0.00 000 000 OAo 000 D.00 O.oO 0.10 000 0,00 0.00 0.00 400 0m O.TJ owl 031 am oAo OJq 0.>i 0.41 021 ON om 0m 0.>9 OAO OSl am am 0.95 Pia Pss dam P38 0.f0 IND •Values enI8r80 into EPA SWMM Walla, Ouar I Provided Location .Aa.l (twos) A. (s0. h) Al (was) A.A.a4 (AMS) (via.) Al (•eras) COMPOSITE •Pemenl Impervious CD Cle I Cleo Aral to North PLD 441 21371145 34 146 O35 000 a.73 0.]a O.T9 171, AM ID SOrtl PLD 926 1g108 2.63 0.<D OSl 000 OAl oaf 011e Aroa to WOPond R,67 $W04e 1 7AJ 7A9 355 000 All I OA1 0,,97HIP dOn Pand J.9) IC0514 DM000 0.15 0W490 0.17 0.11 090 031OatOle00001{ a.93ota)Aroatmatod • r.,r. s6.u,,...., r..... e......,.. 2e.o3 .. Io,W52 13" as 42S 021 a.m a.m 0.m Release Ill Calulat 5 IlSoopara natal Area) Total Basin Areas N.]4 W737p4 m.06 410 426 0.21 0.53 Om OM 60% KIn SO Olt Araa 011Sita BEaln AlOa Troamd 25.09 1Om452 1J94 0.39 t]d70 OAS 1 ON 1 023 426 am 021 0.0 am 0.11 a74 all 0.76 ON )1•b zw 0/13770 Basin Ard abap 26e3ta1 N.tl 33.t9 aro 000 4.3 OAS am 41% Basin DACta+KSWS1.D52 N.94 Mill 3e 05 41.q 425 021 Od] OA3 DA0 60!: Allat>able Release Rate -A•" A. 2S.03 dares 0= 501 efs Provided p¢tease pate O. 4.83 c/s SWMM PARAMETERS-FinaLsls - Basin Summary Page 1 of 1