Loading...
HomeMy WebLinkAboutDUTCH BROS - FDP190017 - DOCUMENT MARKUPS - ROUND 1 - STAFF'S PROJECT COMMENTSPRELIMINARY DRAINAGE REPORT Dutch Bros Coffee Kensington Commons Prepared for: M Squared, LLC 7303 S. Timberline Road Fort Collins, CO 80525 Prepared by: Interwest Consulting Group 1218 West Ash, Suite A Windsor, Colorado 80550 (970) 674-3300 June 26, 2019 Job Number 1380-165-00 Interwest Consulting Group DETENTION VOLUME CALCULATIONS Rational Volumetric (FAA) Method 100-Year Event LOCATION: Dutch Bros. Kensington PROJECT NO: 1380-165-00 COMPUTATIONS BY: es DATE: 6/4/2019 Equations: Area trib. to pond = 0.69 acre Developed flow = QD = CIA C (100) = 1.00 Vol. In = Vi = T C I A = T QD Developed C A = 0.7 acre Vol. Out = Vo =K QPO T PROP Release rate, QPO = 0.4 cfs storage = S = Vi - Vo K = 1 (from fig 2.1) Rainfall intensity from City of Fort Collins IDF Curve with updated (3.67") rainfall Storm Rainfall QD Vol. In Vol. Out Storage Storage Duration, T Intensity, I (cfs) Vi Vo S S (min) (in/hr) (ft 3 ) (ft 3 ) (ft 3 ) (ac-ft) 5 9.95 6.9 2060 132 1928 0.04 10 7.72 5.3 3196 264 2932 0.07 20 5.60 3.9 4637 528 4109 0.09 30 4.52 3.1 5614 792 4822 0.11 40 3.74 2.6 6193 1056 5137 0.12 50 3.23 2.2 6686 1320 5366 0.12 60 2.86 2.0 7104 1584 5520 0.13 70 2.59 1.8 7506 1848 5658 0.13 80 2.38 1.6 7883 2112 5771 0.13 90 2.21 1.5 8234 2376 5858 0.13 100 2.06 1.4 8528 2640 5888 0.14 110 1.94 1.3 8835 2904 5931 0.14 120 1.84 1.3 9141 3168 5973 0.14 Required Storage Volume: 5973 ft 3 WQCV: 774.7 ft 3 0.137 acre-ft 0.018 acre-ft 6-4-19 Detention.xls,FAA-100yr