HomeMy WebLinkAboutBANK ONE PUD - PRELIMINARY & FINAL - 54-87W - CORRESPONDENCE - LETTER OF INTENT0
MIMIUK
Engineering Consultants
2900 South College Avenue
Fort Collins. Colorado 80525
303/226-4955
FAX: 303/226-4971
August 5, 1992
Susan D. Hayes
Stormwater Utility Dept.
City of Fort Collins
235 Mathews
Fort Collins, Co. 80522
RE: Drainage for the Northwest Oak Farm Area
Dear Susan:
The purpose of this letter is to address the drainage design for the northwest area of the
Oak Farm Area in southeast Fort Collins. The area is approximately 22.9 acres of land
bounded on the north by the south right-cf-way line of Harmony Road, on the east by. the
Centerline of Bcardw=lk Drive, on the s :uth by the no, h property line of the proposed
Upper Meadow at Miramont First Filing development, and on the west by the east
property line of the existing Fairway Estates development.
The stormwater release rate for this area .has been analyzed in the past by two separate
drainage plans. The first plan called The McClellands Basin Master Drainace Plan,
required on -site detention using a staged release rate of 0.20 cfs/acre for a 10 year
design storm and 0.50 cfs/acre for a 100 year design storm. This criteria was
superseded by the Oakridge Master Drainage Plan which allowed a maximum storm water
runoff of 0.50 cfs per acre for all storm events from the Oak/Cottonwood Farm site.
With the development of The Upper Meadow at Miramont First Filing, Boardwalk Drive is
planned to extend from Oakridge Drive, southeasterly to the, intersection of Lemay Avenue
and Keenland Drive. The street conveyance capacity for this section of street in the initial
(10 year) storm water runoff is 12.90 cfs of water. When the drainage of the Upper
Meadow at Miramont First Filing, is taken into consideration, the remaining capacity in
Boardwalk Drive for the above described property is 5.57 cfs. Given the area of the
subject property, this yields an allowable release rate for the 10 year storm of (5.57/22.90
= 0.24 cfs/acre) for the subject property. By restricting the release rate for the 10 year
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storm to this level the subject property can develop without additional storm drainage
improvements to Boardwalk Drive.
Based on this analysis, the drainage for the subject area should be designed to detain
the developed storm water from this property and release the runoff at a maximum initial
storm (10 year) release rate of 0.24 cfs/acre and a maximum major storm (100 year)
release rate of 0.50 cfs/acre. Outfall—foWis site's detention should be into the west
flowline of Boardwalk Drive. At these release rates, Boardwalk Drive will convey
developed storm water runoff from this property, to downstream drainage facilities.
By approval of this letter, G.T. Land and the Front Range Baptist Church (the current
property owners) agree to the aforementioned drainage criteria.
Sincerely,
RBD, INC.
S— -
Stan A. Myers, P.E.
APPROVED:
Oak Farm Inc.
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