HomeMy WebLinkAboutDISCOUNT TIRE AT NORTH COLLEGE MARKETPLACE - PDP & APU - PDP120024 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORT
Suite 200
990 South Broadway
Denver, Colorado
80209
TEL 303 228 2300
September 19th, 2012
Glen Schlueter
City of Fort Collins
Stormwater Engineering
281 North College Avenue
Fort Collins, Colorado 80522
Re: Discount Tire at North College Marketplace
Drainage Compliance Letter
The intent of this letter to provide drainage analysis for the development of Lot 7
within the North College Marketplace located at the northeast corner of East Willox
Lane and North College Avenue within the City of Fort Collins, Colorado. Following
is a brief summary of the proposed development.
Existing Site Conditions
The existing site is currently vacant and sparsely vegetated. The proposed overlot
graded pad varies in elevation from a high of ±4,985 feet to a low of ±4,982 feet.
The majority of the existing pad drains easterly in direction at average slopes of
±1.25% where it is conveyed via curb and gutter to the existing North College
Marketplace storm sewer system. Adjacent land uses consist of the following:
o North: Private Drive
o East: Commercial Development (King Soopers)
o South: Commercial Development (Pobre Pancho’s)
o West: North College Avenue
Anticipated Developed Conditions
This site is included as a part of the approved Drainage and Erosion Control Report
for the North College Marketplace Final Development Plan, (“Master Drainage
Report”), prepared by Ayres Associates dated August, 2009. As outlined within the
Master Drainage Report, developed runoff from this site is mostly a part of drainage
Basin P9. The runoff for Basin P9 is conveyed overland to a porous landscape
detention island. During the minor and major events stormwater enters a Type C
inlet and is conveyed to Water Quality and Detention Pond. Anticipated site runoff
characteristics for Lot 7, as outlined within the Master Drainage Report, consist of
the following:
o Area = 1.19 Acres
o ICOMPOSITE = 89%
o C5 = 0.82
o C10 = 0.82
o C100 = 0.88
Developed Conditions
The current proposal for development of the site consists of a ±6,947 square foot
retail sales and vehicle service building with associated parking and landscape
improvements. Proposed grading for the site generally follows the anticipated
drainage patterns as approved within the Master Drainage Report. The proposed
drainage concept consists of sheet flow easterly across the site. The sheet flow will
be conveyed via curb and gutter to existing stormwater facilities offsite and
downstream. Developed Site runoff characteristics consist of the following:
o Area = 1.19 Acres
o ICOMPOSITE = 67%
o C5 = 0.66
o C10 = 0.66
o C100 = 0.73
Conclusion
As identified above, the composite imperviousness of the developed site results in a
reduction from the anticipated developed site imperviousness within the approved
Master Drainage Report; and therefore, complies with the designs anticipated
within the Master Drainage Report.
It is our conclusion that the site substantially complies with the design and
assumptions within the Master Drainage Report. Please consider this letter as the
final storm water analysis for the proposed development of Lot 7 within the North
College Marketplace development. Should you have any questions or concerns
please do not hesitate to contact me at 303.228.2300.
Sincerely,
Kimley-Horn and Associates, Inc.
Gabe Krell, PE, LEED AP
Attachments: Master Drainage Report References
Appendix A
Master Drainage Report References