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HomeMy WebLinkAboutFOSSIL CREEK OFFICE PARK WEST PUD PRELIMINARY - 52 91C - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTFINAL DRAINAGE REPORT ' FOR CAMERON PARK SECOND FILING PREPARED FOR LAGUNITAS COMPANY JANUARY 22, 1996 STEWART & ASSOCIATES, INC. 103 SOUTH MELDRUM STREET FORT COLLINS, COLORADO 80521 970/482-9331 STEWARr&kSSOCIATES Consulting Engineers and Surveyors January 22, 1996 Mr. Basil Hamdan Stormwater Utility City of Fort Collins P.O. Box 580 Fort Collins, CO 80522 Dear Basil: The following is the final drainage report for Cameron Park, Second Filing. Cameron Park, Second Filing is an existing subdivision that was approved by the Larimer County Board of County Commissioners in 1980 and is of record in the Larimer County Clerks records. The subdivision was later annexed by the City of Fort collins and zoned BP - Planned Business. There are 18 lots in the Second Filing and eight lots have been developed. Since this is recorded plat, this submittal is the Utility, Grading and Drainage Plan for Lots 16 through 25 and Tract "A" and "B" which is the remainder of the Second Filing which was not constructed. IThe area of the site in this submittal is 7.35 acres and is in the Fossil Creek Drainage Basin. The site is bounded on the West by the Burlington Northern Railroad, on the North by a commercial nursery, on the East by the developed portion of Cameron Park, First and Second Filings. It is bounded on the South by an open space tract that has been purchased by the City of Fort Collins recently. Tracts "A' and "B" are being preserved as natural areas. There are three existing ponds and several wetland areas and a drainage way on the two tracts that will have minimal disturbance. The North and middle ponds will be used for storm water detention by having a permanent water level �— — and then a storm water storage area above the permanent pond. Two outlet pipes at two elevations rwill be constructed in each of the two ponds. S Lots 16 through 25 are proposed to each have an office building with shared parking areas. [ The site has an existing ground cover of grasses and weeds. There are quite a few trees and some thickets on the property. The sight slopes from the railroad right-of-way on the West to the ponds and drainage way on the East at approximately 6.2% grade. The ten lots have historically drained by sheet flowing to the ponds and drainage way and the developed drainage pattern will, remain the same. The site has been divided into five sub -basins. The fstorm water runoff calculations for the five sub -basins are included as a part of this report. James H. Stewart and Associates, Inc. 103 S. Meldrum Street P.O. Box 429 Ft. Collins, CO 80522 303/482-9331 Fax 303/482-9382 January 22, 1996 Page 2 EROSION CONTROL: The site is in a high rainfall erodibility zone and in a moderate wind erodiibility zone. Erosion control will include a silt fence along the West side of Tracts "A" and 'B". Also, straw bales will be placed where storm water runoff enters the ponds at concentration points. Any area that does not have to be disturbed for grading reasons will not be disturbed. This drainage report and the design of the drainage system are in substantial compliance with the City of Fort Collins Storm Drainage specifications and criteria. If you have any questions regarding this report, please call. Sincerely, Richard A. Rutherford, P.E. & L.S. President rsc 1*1 5028 A g, enclosures �'�.'`%�'� F �•.d UM, FORT STEWART$6SSOC(ATES 103 S. MELDPH 482- 33 RFAX 482-9380LLINS, CO 80521 Consulting Engineers and Surveyors By: Date: 1- LL 5S Client: LAf,Q&%-Ws Sheet No. 3 of _ Project: FOSSIL C2¢2l�- �Pr2 F� Z Subject: R" RTA 1 i Soo ,_ ....cam^^.... , .. I 90 January1996 2 Year Time Of Concentration/ Intensity Calculations For: Fossil Creek Office Park, Phase 2 By: Stewart and Associates T() = 1.87(1.1—C*qD^1.2/(S^1/3) T(c) = Length / (Velocity * 60) Yard slopes are assumed to be 2% unless otherwise indicated. NOTES: Intensities are based on information from the City SDDCCM Fig 3-2 January 1996 . .. ...... ............ . - F —DB-5 Overland 80.0 2.01 1.3 ... . . .. .......... ............ . ...... .............. Grass Channel 1 0.01 0.01 0.0 0.0 I Concrete Channel 805.01 2.01 1 2.81 491 "1...'...* .... . . ....... . .... i i in = 141 innif an mr mqQin Overland 90.0 1 2.01 1.41 .. .. ...... ...... . ...... Y'r Grass Channel 0.0 0.010.0 0.0 3S I Concrete Channel 350.01 2.01 1 2.81 2. I - ....... 4m- .. 46 .59 ............ Overland 130.01 2.01 1.71 Grass Channel 0.01 0.01 1 Concrete Channel 80.01 2.01 1 2.81 0. ...... ........... fn:U� ... Standard Form SF-9 Calc'ed.By: AVE Date: 1-96 Checked By: FDB Lot to sw lc Lotto pond DEVELOPED FOSSIL CREEK OFFICE PARK, PHASE 2 Storm Drainage System Design (Rational Method Procedure) Desig This area contributes to the newly developed storm drainage facilities for Fossil Creek Office Park, Phase 2 NOTE: TOC computations ii :>: :OIRFfST RIIAtffiCC:- _ 1.44 --IQ = pro,ect area in acres NOTE — .81 X DEVELOPED FOSSIL CREEK OFFICE PARK, PHASE 2 Storm Drainage System Design (Rational Method Procedure) area contributes to the newly developed storm drainage facilities for Fossil Creek Office Park, Phase 2 NOTE: TOC X 0� 0.85 1.44' area in acres Flow Job No. 1579 Project: Hill Crest P.U.D. Design Storm: 2 Year ions include overland, channel but not pipe times VICINITY MAP SCALE - 1"=1000' ��wh�.SE • � —7 .._i c f