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Home My WebLink AboutDrainage Reports - 07/29/2011City of Ft. Collins App ved lans ,. Approved By �ya1� Date Perception design group) inc. 6732 W. Cod Mine Ave., Suite 419 Littleton, Colorado 90123 Voice 303-232-8088 Fax 303-232-5255 May 31, 2011 Mr. Glen Schlueter City of Fort Collins Stormwater Engineering 281 North College Avenue Fort Collins, CO 80522 RE: Mountain View Eye Specialists - Lot 2 Rigden Farms Fifteenth Filing Dear Mr. Schlueter, As a part of the Project Development Plan submittal of the above referenced project, Perception Design Group has examined the existing approved drainage report for the site as compared to the proposed development. The site was originally studied by CLC Associates in a report entitled "Preliminary Drainage Study for Rigden Farm Tract A" and dated December 8, 2009. In this report assumptions were made as to the drainage basin demarcation, impervious coverage, and runoff outfall location. Included in the appendix is the original CLC drainage map, selected pages of the Study, as well as a drainage map created for the Mountain View site. Grading along the basin lines is unchanged from that presented on the CLC map. The original basin lines are overlain on the Mountain View drainage map. Minimal grading changes are proposed in the vicinity of the basin lines therefore drainage basins remain as shown on the CLC map. In the text of the CLC report assumptions are made for the future imperviousness of basins A and B. Basin A will have no change in impervious coverage from that presented in the CLC report. Basin B assumes an impervious coverage of 90%. Actual impervious calculations for the Mountain View project indicate an impervious value of 75.7% for Basin B. Impervious calculations are based upon the lot area within basin A as well as the ROW out to the median as shown on the drainage map. Therefore, impervious coverage is in conformance with that presented in the CLC Study. On the CLC map, runoff from Basin A is directed to the northeast corner of Lot 3 indicated as design point 2. A concrete trickle pan is in place along the north side of lot 3 to intercept runoff and convey it to design point 2. This trickle channel is extended across the north side of lot 2 to convey storm water from the Mountain View project to design point 2. Additionally a trickle channel is added along the east side of lot 2 to bring parking lot runoff around the building and prevent runoff from entering lot 3 where a future building or improvements may be constructed. 'Nuisance runoff from the front canopy along with a small area drain are collected on the west side of the building and piped to the northerly drain pan. This pipe is intended for nuisance flows only and therefore no sizing calculation is included. Runoff in Basin B is not altered from the CLC plan with the exception of adding a curb to the south side of the access drive. Storm water will flow along the curb and discharge into the ditch as originally intended in the CLC study. As the ultimate outfall location for site runoff is unchanged from the CLC Study, outfall location is in compliance with the CLC study. Mountain View Eye Specialists - Lot 2 Rigden Farms Fifteenth Filing Page 2 of 2 The CLC Study indicates water quality for Rigden Farms 15a' Filing is provided in Water Quality Pond #2 as presented in the "Rigden Farm, Filing One Drainage Report (Master) prepared by JR Engineering dated October 1999. Additionally, site detention is provided in Fossil Creek Reservoir which is also presented in the JR Report. Therefore, detention and water quality for the Mountain View site will be provided in the aforementioned off site locations. In summary, The Mountain View Eye Specialists development located on Lot 2, Rigden Farms Fifteenth Filing is found to be in conformance with the original drainage study prepared by CLC Associates for'_ANiW— 5 Jerry For a N Inc. MOUNTAIN VIEW EYE SPECIALISTS LOT 2, RIGDEN FARM - FIFTEENTH FILING, SITUATED IN THE NW 1/4 OF SECTION 29, T.7N., R.68W., OF THE 6TH P.M. CITY OF FORT COLLINS, COUNTY OF LARIMER, STATE OF COLORADO. J*allan k4im maims Goo '0"'w - -CUSTER DRIVE NA . 'I'.' S8903328E164.65' 3 CONCRETE DRAIN PA LEGEND Ih PROPERTY UNE MOUNTAIN VIEW EXISTING CURB AND GUTTER EYE SPECIALISTS 2.� 00 S.F. 4.960 SQI FT. PROPOSED CURB AND GUTTER M=4933.39 F JTURE N 11 1 EX 'ANSIO PR DRAIN CONCRETE N A. PROPOSED SIDEWALK PROPOSED HANDICAP RAMP IlAll 111A III" E7771HEAVY-DUTYIUA\ C OPOSED HEA-DUTY OttCRETE PAVEMENT A.,' I — — — — 5,89— — — — EXISnNG CONTOUR PROPOSED CONTOUR EXISTING SPOT EI-EVAnON PROPOSED SPOT R FVATION LOT JlJv RIGDEN FARM - FIFTEE FILING PROPOSED DRAINAGE "N BASIN BOUNDARY DRAINAGE BASIN DESIGNATON OC 2-YEAR RUNOFF COEFFICIENT 095 100-YEAR RUNOFF COEFFICIENT 1.00 BASIN AREA IN ACRES now 'a an 4 CONCRETE CROSS PAN EXISTING DRAINAGE DITCH GRAPHIC SCALE 1. z DRAINAGE PLAN SHEET I OF I MAY 31,2011 PRIVATE DRIVE 0 Perception CIl ^_ ', Design Group, Inc. Ave.. 'mu,419 Ulln .Col-IoMW 0M.303.232-8088 1.3.3-232-5255 No Text i� 1 F, r � � .. n a i '.. �. � � 4 .. , _ � � - _ _ _ � � _ .. .. � it r .. _. ... ._ .. � -. _ .. .. I No Text _ Di5dM OY b 1 hVi 5 ' ev, 6Y > WK,06s - - - - - . AaW-Y.'Iff(,fK0K 1.71:4ItJ} T- . VAIT:112>ia 9 C-VALUES FINAL CONDITION " . .17iF.A " C2 -` .CLO ' - CI00, . °o:DMERV 0211 , "`0:20 .0.95 'P 0.95 - 1A0: 90 , . CO,N(:RF_TE ''^ 0.00- _` ;0.95.. _ 0.95 90 - PAVEMEM C=, 0.64 - CIO= 0.64 - T.W Basin Arcs.. _ 11.09 :. Rvin Impem 'CUlll= r BASING AREA. C2. CIU 'CI00 ;4e Ih1PERV ULNIDSCAJ4NO 0.00 0.20 0.20 .' 0.25 .- :S. ROOF - - '0.95 " 0.95 1.00, 90 CONCRETE - ().95 0.95 : I.UO'- , ' 90 .. PAVEIMNT' - L56 -=`.0.95 0.93 I.00t' - 90. .. ' CI0- 0.95 Total Blain Ams - CI00= 1.00 Rminlmpenioui-. ' 911% I \I I I 1 I I I I I I 1 I I I I I I I I I I I I I I I I I I I i I 1 nl 111 111 I II 111 I II II 1 I1 II I 1; 1 II II I 11 I II I 1�1 II I I I II I I I ;1 I II it 11 I II I II � II 11 �' II 11 I I I I II I I I I II �I I I I I ! / Rldm F. Bth PNA9 NOT A PART \ / C LISTER DRIVE /p (861 R.OWJ ----- ----- (� ---____---�vnnr+nn�al :a_tJ'QI#'rti4'l:L+.t?-!�9�7'rLiagas REND a gr idlj7llllue t'1-G-V,- �� p�\ .Tr --r -` _ ___ m� SERI EXIT. 5 CONC. WALK f -. _ __- n_ iA I _ E3♦- COO w GD_ x —' _ S QE EMT 9 UGL. CASEMENT E%I•fr4 GRASAT.A -- Re ihdrr of Tnq Aot / E•93 (IL� -- TROP RSUPLIT�Eq .•• - - / AigdN TA ART One /ar m.v / [3 I( 15 ,nrt �n_m_u'C PROP�CD 15' AV SE UTILITY E SEIREMENT l / PROPOSED 4933 6' ACCESS ESMi.- A LOT 1 0. 64 /F- 1.71 0.89 - - - PROPOSED ACCESS, _ UTILITY & EME30' RGENCY. -�' - ACCESS EASEMENT L DRAINAGE ESUL - _ PROPOSED ACCESS -EASEMENT (BY SEPARATE DOCUMENT) � 1 DRIVEWAY I, I I I III r I LOT Z MENT/ I I I I I I I / I I �EMISi 9' NTIL. PROPOSED EO'i GSEYENi NYOPLAST INLET mTN C.I. GRAZE 1A Ih! PROPOSED 1' UTILITY EASEMENT y I w l IIW II II LOT 3 II I 1 ii I 'I I logo ^-"rF}L=ry C1Jf iL-7i�3 [ �t 3C�'�C' in1T PROPOSED 24 ACCESS, UTIUTT & ERER CROY ACCESS EASEM T — — — — 1 1 -% 4931 - -49J �9 ExIS. GRASS AREA F, _. ROPDSED 19'v30 EPC'P NLVERi _ _ EXIST 5—COAL NALN — — i O— _ _ _ —4 EXISTING ACCESS, DRAINAGE AND UPUtYEAGEMFNj I - - - - - 1 / -- Sao ch."h NCTTAPART iOPOSED 12' RCP it I 11� 1 1 'III �I a 1 II i II II j11 �il gF wl z �! A I j Z I I ;I I i I l I I I I z E I LEGEND - - PROPOSED LOT LINE PROPOSED CURB ® - ® EXISTING CURB PROPOSED CONCRETE SIDEWALK EXISTING SIDEWALK _ - - - NC ACCESS RAMP LS LANDSCAPED AREA PROPOSED STORM SEWER —5300— PROPOSED MAJOR CIXITOUR —5002— PROPOSED MINOR CONTOUR ---5300— EIIISTNG MA" CONTOUR ___5 G2-- -- EXISTNG MINOR CONTOUR ®gNINNEE SUB -BASIN BOUNDARY eel DIRECTION OF FLOW 1Q DESIGN PONT Nomm ao o ,e aO eoAlc: I• -add BASIl.251 C2 1.25 .g8 AREA IN C100 ACRES t I \ \1 I I / / CITY of Fot Ccitinw, CabodO - UT{jiY GL.AN OYu 0.AE Tees PLANS NAME BEEN REYEeFD BY TIME QTY OF Pi CMI'm CCHM" ONLY. THE tlEOID 8 : 'ice- REMEW GOES NOT pI�LY:RlSPOIL4q]tt BY TIE REYEYdNC LE9AfT1=L l QTY OF FORT W ! DA COWNS ENGWEM OR THE CITY Q f1tRt OEOTD BY: - L -/d COLIIHS FOR ACtlMACT AMID CORREF11NE55 OF SIQMIP DATE THE GJyQlLATRTG F1Q1Y1@ *0M THE RE)"Ell OEgIID BY I_ ERIC PEWS ARE THE MUL OUAN11T2S R . PARYS E MEWX iNE RE _ SMAIL NOT wCOED a ANY AS ACCEPTANCE OF lllllf L CKCXEp Ell.."' MT COULIEtt WMTTQTFSS F TRA1F vlmEm DATE DwTMi OTY i SWIM THAT MAY RE REQ lRE) DORM TIME I]IEO® BT. CONBiRUGTON PHASE .. _ DAR I HDEEBY ARFPRI EVERT M FOA HE A Ott aF OF A 0 TIN 1K IAIOAIN.Y OF Nr1 DAMEL J. IMUNGIX PE J CO MADO IEOGTMIIOM ME, CLC ANRQCIATC■ Ll g (L F f Fa (] U � QQ � FZ_l W:i a ZJU oo� QUA Z 1,-1 O It ILL M0 Z 8) w z a O o ❑ R ..! : IJA oe91a N[M 9Y: ollcaa.. eY: wM