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Home My WebLink AboutTACO BELL RESTAURANT PRELIMINARY AND FINAL PUD - 51-90A - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTPRELIMINARY DRAINAGE INVESTIGATION FOR PROPOSED TACO BELL RESTUARANr FORT COLLINS, COLORADO Prepared for AHC[ TTEC WHE OO Mn a 150 East 29th Street Suite 200 Loveland, Colorado 80538 October 28,1991 Project No. GRD-040-90 PREPARED BY. HMOUM Engineering Associates 150 East 29th Street, Suite 225 Loveland, Colorado 80538 Telephone: (303) 663-2221 Civil and Environmental Engineering Consultants October 28, 1991 Project No. GRD-040-90 Mr. Al Hauser, Architect ARCHITECTURE ONE 150 East 29th Street Suite 200 Loveland, Colorado 80538 Dear Mr. Hauser, The enclosed report represents the results of a preliminary drainage investigation for the proposed TACO BELL to be located on Lots 7 thru 10, Block 6 of the R. C. Moore's Second Addition to the City of Fort Collins, Larimer County, Colorado. This investigation was based upon the proposed site development plan and plat; proposed site grading plan; on -site observations; and available topographic information. The investigation was performed in accordance with the criteria established in the City of Fort Collins "Storm Drainage Design Criteria and Construction Specification Standards" manual. Thank you for the opportunity to be of service to you. If you should have any questions, please feel free to contact this office. Submitted, Dehnis R. Messner, P.E. MESSNER Engineering Associates DRM/mkm Enclosures Civil and Environmental Engineering Consultants 150 E. 29th Street, Suite 225 Loveland, Colorado 80538 Telephone: (303) 663-2221 TABLE OF CONTENTS Letter of Transmittal Table of Contents Scope Site Description Existing Conditions Proposed Development Erosion Control Measures Conclusions and Recommendations 1 2 2 2 EXHIBITS Vicinity Map Existing Conditions Exhibit Grading & Drainage Exhibit Calculations ii SCOPE The following report represents the results of a drainage investigation for a proposed TACO BELL restaurant to be located on a parcel of land situated in the Southwest Quarter of Section 13, Township 7 North, Range 69 West of the 6th P.M., Larimer County, Colorado. The site legal description is: Lots 7 thru 10, Block 6 of the R. C. Moore's Second Addition to the City of Fort Collins.The investigation was performed for ARCHITECTURE ONE. The purpose of this investigation is to determine the effects of the proposed development on the area's existing drainage conditions and to determine the improvements, if any, and the appropriate sizing for proposed improvements so that it may be incorporated with the construction of the project. The conclusions and recommendations presented in this report are based upon the proposed site development plan and plat; proposed site development construction plans; on -site observations; and the available topographic information. The analysis was performed in accordance with the City of Fort Collins "Storm Drainage Design Criteria and Construction Standards" manual. SITE DESCRIPITION The site is rectangular in shape and contains approximately 0.703 acres. The site's East-West dimension is approximately 143 feet and its North -South dimension is approximately 213 feet. The site abuts the easterly right-of-way of College Avenue and the northerly right-of-way of Prospect Road. The site is located In the SPRING CREEK DRAINAGE BASIN. EXISTING CONDITIONS The site presently consists of two separate uses. A brick structure is located on the northern half of the site. This structure was originally constructed as a single-family residence but has been utilizied as an office building for the past several years. A TACO BELL restaurant is located on the southerly half of the site at the Northeast corner of the intersection of College Avenue and Prospect Road. The site slopes gently from North to `- South toward Prospect Road at a slope of approximately 3%. The site does not receive - run -off from the properties to the North. The runoff generated on the adjacent property is directed westerly into the gutter of College Avenue or easterly into the alley. Runoff that enters both the gutter in College Avenue and the alley flows southerly to Prospect Road. A storm inlet that is located at the easterly end of the curb radius at the northeast corner of the intersection of College and Prospect intercepts flow from the north. Excess flow continues easterly along Prospect to Remington and then southerly along Remington to Spring Creek. PROPOSED DEVELOPMENT The proposed re -development of the site is to consist of the demolition of the existing TACO BELL structure that is presently situated on the southerly portion of the site. The existing residential/office structure that is located on the north side of the site is to be renovated to be used as the "new" restaurant structure. The parking, landscaping and driveways associated with the "new" restaurant will be places following the existing structures demolition. The sequence of construction and demolition is anticipated to be 1 PROPOSED DEVELOP1viENT(cont.) such that the existing restaurant will remain in operation while the existing structure is being renovated. Other improvements that will ultimately effect the grading and drainage for the site is the proposed reconstruction of Prospect Road. This construction is being proposed in order to provide channelizing and turning lanes to improve traffic flow in the area. In order to do this the street will be widened. The curb and gutter is to be shifted to the North a distance of 15.5 ft. along Prospect Road in order to provide additional turning lanes. This roadway widening will also require that the existing storm drainage inlet located at the northeast corner of the intersection be reconstructed. The proposed grading and drainage plan for the site has taken this proposed construction into account. The perimeter grades have been established by continuing the crown slope grades of the existing roadway to the proposed gutter locations. EROSION CONTROL MEASURES Erosion control considerations have been made based upon the short term,i.e., during construction activities and the long term, through the life of the facility. The long term measures incorporated to eliminate erosion are the proposed methods and materials to be used to provide a surface covering for the driveways, parking areas, walkways and the landscaped open areas. The structure and hard surfaced areas will provide a covering to deter erosion. The landscaping to be established will be a combination of plantings and ground covers to deter erosion.(Please refer to the proposed "Landscaping Plan" prepared by the project's Architect) The short term erosion control method to be incorporated into the construction requirements for the project is the placing of a "sediment trap" at the proposed storm drain inlet to be constructed onsite. It is not considered as necessary to provide any wind erosion measures due to the protected nature of the site. The schedule of construction activities is anticipated to such that the site will be "open" and subject to water caused erosion for an extremely short period of time. This is due to the existing restaurant is to remain in operation while the existing structure is being renovated. The demolition of existing facilities and subsequent grading and paving operations will be scheduled in a manner that will place the "new" restaurant in operation as quickly as possible. Therefore, depending upon the sequence of activities it may be possible for no temporary measures to be required. CONCLUSIONS AND RECOMMENDATIONS 1. The proposed development will retain the existing drainage patterns. 2. The site is located in the SPRING CREEK DRAINAGE BASIN. The site is not located within the floodway or flood plain. 3. All development is to be performed in accordance with City of Fort Collins Standards and Specifications. 4. Onsite detention of stormwater is required by the City of Fort Collins. The difference between the existing and proposed conditions is estimated to be 24 and 48 cu. ft. for the 2 Year and 100 Year Storms respectively. 5. The City of Fort Collins Standards for temporary erosion control measures are to be incorporated with the construction activities. Specifically, a sediment trap is recommended to be placed at the proposed storm drain inlet onsite. 2 VIEINITY M-AP'A �� ?q. 0 0 0 > O0 Oil m o 11 SCALE:.1 "-20' ° � v II N .... A 0 O I ' n n �i► -n (nW � 4 w D �� aa• n Div R/RTIE IV I Ian OF40" 9S> 9SD — RT1E 00LINE pW as W O \S------- 143.8T' p a� ::i Fg 9y>9s3T M� FENCE 00 LIWE C�KAVEL ORIVE ° oa PEP. ELEG. I ' PHONE PED. d' co 1 J 9.Z' Q n 3o.to' R\ - f 1 STORY BRICK m N y ��. atio W/BASEMEti1T 49, 64AvE4— I $ w R BRICK F'— 31o"O 3S 1530 S. COLLEGE ' _ Su2F/tcg_ GARAGED 5.8 �. 9 F.F. _ :.m. F.F.= 9(o.4Z 9.0' a 93.b1 Ile,F.F. L.L. = 16 1.41 Il. A\JQ - 1p O�� • - - Pti. Dn U1\• O 93 3.9' 1 b.l' oc - r2..' '.. O � 9�80 .o LL „ ` r�7 n O z F ��• po 040 M 0??C72liV- .,-.: la'o n� 6RICK 24,. O DU P5TE T' ILRR/TIE ° OIJE PEP. E \L 91,TAIh11JG WALL , .. a° A07I ASPHALT 1• ?� cic i �o�� GAS v,° I• 35� �� I.• -.:. ". qI �'� � i°%o.` METER-- ' moo`' �: • >.. 5TOOE ; . •-.: ASPHALT J �.:.. 72 �•:Y - � �- 1 STCRY MAjGI-IR`i —1 .- �� - w 1 TACO BELL �ESTAUF- KIT ' �, u Y j: STONE n co� ' F.F..O 0�1 I1L. p[ 0.p N ` I Ij 4�.4 0: O II •- N II :1 I 86T hI ti SIGtie 9Q FO I p 1 O /P 99? O -n y 0 U o ASPHALT Q 0 is O gyp. -TRAFFI(- 51GWAL 2 • i coWTeoleR- . Q � • 3 3�x �:�� i 00.�4 CF �4,c TRAFFIC SIGOAL- \ I , 49 C 99rr -. I MAST \` COWC. CURB, GUTTER, rSIDEWALK: . *WA-TEK". ... -: a�V MANI VOLE 8Sy FLOW LINE : •.: % .... I gyp. �ro L/o CSrd" 1/1/Er) iF CURB CUT AREA = 0.96 AC. p Q2 = 2.0 CFS Q 100 = 6.3 CFS �w PROSPECT ROAD AREA = 2.39 AC. Q2=4.2CFS Q 100 = 15.2 CFS EXISTING CONDITIONS EXHIBIT i It Client: ARCHITECTURE'ONE By: DRM Project No. GRD-040-90 Date: Oct. 28, 1991 Calculations for Drainage Investigation for Lots 7 thru 10 , Block 6 of R. C. Moore's 2nd Addition located in the SW1/4 of Section 13, Township 7 North, Range 69 West of the 6th P.M., City of Fort Collins, Larimer County, Colorado Total Site Area = 0.703 ± acres of existing platted property The proposed development of the site is to consist of demolition of the existing structures on the site and the construction of a new TACO BELL restuarant. The site will be required to dedicate property along College Ave. and Prospect Road due to proposed street widening projects proposed to occur in the near future. The net area of the site after right-of-way dedication is anticipated to be: Net Site Area = 0.634 ± acres EXISTING CONDITIONS - RUNOFF COEFFICIENT Rational "C" Factor = 0.20 for Lawns and Landscaped Areas = 0.95 for Roofs, Decks, Patios, etc. = 0.95 for Asphalt and Concrete Streets, Drives, and Parking = 0.50 for Gravel Streets, Drives, and Parking "C"avg (Existing) Lawns and Landscaped Areas = 3,728 sq.ft.± Roofs, Decks, Patios, etc. = 7,649 sq.ft.± Streets, Drives, and Parking = 12,196 sq.ft.± Gravel Drives, and Parking = 7,050 sq.ft.± Total Site = 30,623 sq.ft.± "C" avg = {(3,728 x 0.20) + (7,649 x 0.95) + (12,196 x 0.95) + (7,050 x 0.50)) = 30,623 = 0.755 "C" avg = 0. 755 PROPOSED DEVELOPMENT - RUNOFF COEFFICIENT "C"avg : Lawns and Landscaped Areas = 7,490 sq.ft.± Roofs, Decks, Patios, etc. = 2,825 sq.ft.± Streets, Drives, and Parking = 20,308 sq.ft.± - - Total Site = 30,623 sq.ft.± "C" avg = 0,490 x 0.20) + (2,825 x 0.95) + (20,308 x 0.95)) = 30,623 = 0.767 "C"avg = 0.767 TIME -OF -CONCENTRATION Time of Concentration (Roof to Ground) = 5 minutes Time of Concentration (Ground to Street): Tc(min.) = 1.8 [ 1.1 - (C£ x C) ] 4L(ft.) + 34S(%) Time of Concentration (Street Flow): T(min.) = L(ft.) - [Vel. (ft./sec.) x 60 min./sec.] TTotal = TRoo£+ Tc + Ts Page 1 of 2 Client: ARCHITECTURI3 ONE Project No. GRD-040-90 By: DRM Date: Oct. 28,1991 EXISTING CONDITIONS TIME -OF -CONCENTRATION Tc = 1.8 [ 1.1- (0.755 x 1.0) ] 480 + 342.9 = 3.75 min.(Overland Offsite to North) Ts = 350 + [ 2.5 x 60 ] = 2.33 min.(Street Offsite to North) Ts = [230 + (3.5 x 60) + 150 + (2.5 x 60)] = 2.10 min.(Street Adjacent to Site) TTotai = Ts +Tc + Tr Therefore, T = 2.33 + 2.1 + 5.00 + 3.75 = 13.28 min. USE 10 minutes as Time of Concentration for Point of Concentration located at the Southeast Corner of the Site I2 Q 10 min. = 2.50 in./hr. RUNOFF Runoff, Q = C x I x A x Cf Cf at 2 year Storm = 1.0 EXISTING CONDITIONS: Q2 = 0.755 x 2.50 x 0.703 x 1.00 = 1.33 c.fs. Qioo = 0.755 x 7.25 x 0.703 x 1.25 = 4.81 c1s. PROPOSED CONDITIONS Iioo @ 10 min. = 7.25 in./hr. Cfat 100 Year Storm = 1.25 Q2 = 0.767 x 2.50 x 0.703 x 1.00 = 1.35 c.fs. Qioo = 0.767 x 7.25 x 0.703 x 1.25 = 4.89 c.fs. The estimated difference in total runoff volume based upon the 2 and 100 Year Storms Determine Volume if Detention were to be provided. Time Q2Proposed Vol. Q 02 Qpis, OQ 2 Yr. Vol. as. Vol. Diff. 10 (min.) 1.35 (c.f.s.) 822 (cu.ft.) 1.33 (c.f.s.) 798 (cu.ft.) 24 (cu.ft.) 15 1.13 1,019 1.33 1,197 (-178) 20 1.00 1,200 1.33 1,596 096) Time QiooProposed Vol. @ QM QDis, Q 100 Yr. Vol. as, Vol. Diff. 10 (min.) 4.89 (c.f.s.) 2,934(cu.ft.) 4.81 (c.f.s.) 2,886(cu.ft.) 48 (cu.ft.) 15 4.04 3,636 4.81 4,329 (-693) 20 3.50 4,200 4.81 5,772 (-1,572) Therefore, volume of 24 and 48 cuff. would be detained if detention were to be provided. Page 2 of 2