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HomeMy WebLinkAboutDISCOUNT TIRE AT FOSSIL CREEK - PDP/FDP - 26-02 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTFloodplain Vicinity Map a^ Q Q W iW U. u- � G t8 w I 0 CO O • I Qj _O fn F �O I2Cq� trQ ��y� e' m Q tL � FCssi OS,St rtrt�y`a N M E NProduct Corridor Property located: SE of College S Fossil Creek Pkwyn1° N10mwabon IS bawd on n° FOCWW EmMgerwy MatuYenWg City of Fort Collins Community Number ��F ay >Thbap l4�Wdon n b"a NCity Limits VWftraMxcetlPfopedywNwwinot beIm1h looft r The property is located on panel number: 0014C LIWRage. A pmp"rM In ft SpOdWRod Na=W Am Ina dmaged ® Floodway The date of the FIRM index: March 18, 1996 aMwOWpfodc a�n"ftmap a6a tbe atahwa piobW, not sW m w tna maprnw map dose not aaW kWy w ft Shallow Flooding The FIRM Zone: X W�ro « mm � +wW,br" dwnao Property is located In the ®100 Year Floodplain City -designated Fossil Creek Floodplain. ® 500 Year Floodplain All fioodplain boundaries are approximate. C i I I 1 I I 1 I I I r I u I I n' ' o i Harmony Road Palmer \ � b m 0 V Drive ; r 2 y ` c o a Fairway Lane \ _ b ` \ SITE 3 Apple Blossom Lan b Fossft VICINITY MAP SCALE. 1 " = 850' N I 19 I before entering the WQC Pond. The Northeastern swale travels through a 15" pipe underneath the proposed access drive before entering said Pond. Sub -basin "B" is to the South and contains 0.65 acres of undeveloped ground. Runoff from this basin will continue to be by sheet flow into Fossil Creek. This basin is entirely within the 100-year Floodplain. The WQC Pond is designed to hold the Extended 40-hour Detention Volume based on City guidelines. Runoff from Fossil Creek Parkway will be intercepted in curb t and gutter and kept off -site. Grades on the access drive must be raised, even though in the "no -build" floodplain, and an 8' concrete pan will be used to ensure said runoff remains off -site. A standard, F high WQC device shall be used in the pond. 1 I EROSION CONTROL: The site is in the City's Moderate Wind Erodibility Zone and in the High Rainfall Erodibility Zone. A silt fence will be constructed prior to construction and left in place until all construction is completed. A straw bale dike will also be constructed around the WQC device to prevent silt loading in Fossil Creek. Prior to seeding, the pond bottom will need to be re -graded to remove excess fines collected during construction. The pond and drainage swales will need to be reseeded as shown on sheet 3 of 4 of the utility drawings. Required escrow to the City of Fort Collins for erosion control is $2400. C I PRELIMINARY DRAINAGE & EROSION CONTROL REPORT FOR ' DISCOUNT TIRE P.D.P. INTRODUCTION: This project will construct a single -story commercial building, parking areas, an access drive, and a water quality control pond for the developed portion of the site. Approximately 64% of the site is located within the 100-year floodplain of Fossil Creek as defined by the updated City of Fort Collins Master Drainageway maps. The site is located in the Northwest '/a OF THE southwest '/a of Section 1, Township 6 North, Range 69 West of the 6t' P.M., City of Fort Collins, County of Larimer, State of Colorado. The site is on one of two adjacent commercial envelopes on the western edge of the Fossil Creek Meadows Subdivision, I" Filing. EXISTING CONDITION: The site is bound on the North and East by Fossil Creek Parkway, on the South by Fossil Creek, and on the West by South College Avenue (U.S. 287). Improvement plans are underway for Fossil Creek Parkway and have been incorporated into this design. There are no existing Storm Drainage structures in place on this site. Runoff is sheet flow over medium soil with 6-inch grass cover at 2.5%-3% average slope to the Southeast. Approximately 60% of this site is located within the 100-year "no -rise" floodplain, as defined by the City of Fort Collins Master Drainageway Plans. This design matches existing grades as much as possible so as not to create a fill in this floodplain zone. A Floodplain Use Permit will be required prior to any construction. DEVELOPED SITE: ' We are proposing to develop one, single -story commercial building and appropriate parking, access, and landscaping. Because of the proximity to Fossil Creek ' no on -site detention is required. The Water Quality Control (WQC) Volume will be detained on -site and released through a 12" pipe into a geo-fabric protected drainage swale and into Fossil Creek. There are two sub -basins on this site. Sub -basin "A" is to the North and contains the entire 1.90 acre developed site. Runoff from this basin is to the WQC Pond located in the Southeast portion of the site. Runoff from the parking lot is concentrated along the Southern flowline of the curb and gutter and enters the pond through two 2-foot curb cuts. Runoff from the roof of the building and from grassed areas in sub -basin "A" is through two drainage swales. The western swale receives flow from the two curb cuts B I 1 1 a [1 I STEWART&ASSOCIATES Consulting Engineers and Surveyors April 21, 2002 Mr. Basil Hamdan Stormwater Utilities City of Fort Collins P.O. Box 580 Fort Collins, CO 80522-0580 RE: Discount Tire P.D.P. Dear Basil, This project consists of one commercial building with appropriate parking and a water quality control pond. Construction for this project is slated for Fall 2002. This project is in the Fossil Creek Basin and is contiguous to Fossil Creek. , 1 The site is located in the Southwest'/4 of Section 1, Township 6 North, Range 69 West of the Sixth P.M., City of Fort Collins, County of Larimer, State of Colorado. The project is located in Commercial Envelope `B" of the Fossil Creek Subdivision, I' ' Filing. South College (US 287) borders the site on the west, Fossil Creek Parkway borders the site on the North, and Fossil Creek borders the site on the South. ' All designs and calculations within this report are in compliance with the City of Fort Collins Storm Drainage Design Criteria and Construction Standards. All basins in this project use the rational method for runoff calculation. ■ If you have any questions or need any more information regarding this report please call. A James H. Stewart and Associates, Inc. 103 S. Meldrum Street • P.O. Box 429 • Ft. Collins, CO 80522 970/482-9331 • Fax 970/482-9382 TABLE OF CONTENTS A-C Cover Letter and Text D Vicinity Map E Floodplain Map 1-10 Storm Drainage & Erosion Control Calculations Pocket Overall Grading, Drainage & Erosion Control Plan a FINAL DRAINAGE AND EROSION CONTROL REPORT FOR DISCOUNT TIRE P.D.P. PREPARED FOR DISCOUNT TIRE May 21, 2002 PREPARED BY STEWART & ASSOCIATES, INC. 103 S. MELDRUM STREET P.O. BOX 429 FORT COLLINS, CO 80522 TEL: 970-482-9331 FAX: 970-482-9382