HomeMy WebLinkAboutDrainage Reports - 10/12/1990STORM DRAINAGE REPORT
PART OF TRACT "K" ...
SOUTHMOOR VILLAGE FIFTH FILING
PREPARED FOR
JIM JOHNSON
PREPARED BY
STEWART & ASSOCIATES. INC.
OCTOBER 2. 1990
LOCATION:
The site is Tract "K", Southmoor Village Fifth Filing situate in the Southwest
=, of Section 25, Township 7 North, Range 69 West of the Sixth P.M., Fort
Collins, Larimer County, Colorado. It is bounded on the south by The
Foothills Mall; on the east by Tracts Five and Six of the Foothills Fashion
Mall Expansion; on the north by Thunderbird Estates, and on the west by
Mathews Street. All of these subdivisions are developed.
EXISTING CONDITIONS:
Tract "K" is an existing building, sidewalks, landscaping, parking and access
to Mathews Street and to the access drive south of the site. There is an
existing grass area north of the building. The existing runoff from this
grass area to the access drive and parking north of the existing building
on Foothills East is Q2 = 0.11 c.f.s.; Q1n = 0.20 c.f.s and Q100 = 0.39 c.f.s.
The remaining portion of the site drains io the southeast corner of the
property and to Mathews Street. There is no planned construction for these
areas.
DEVELOPED SITE:
The existing site will remain as constructed EXCEPT for the grass area north
of the building. It is our proposal to construct an asphalt parking area
in this grass area. This report designs only for this area. The area is
0.21 acres, more or less. The developed runoff is Q = 0.68 c.f.S.; Q
= 1.16 c.f.s.; and Q100 = 1.58 c.f.s. The required getention is 1570 cubic
feet and the required outlet rate is Q = 0.11 c.f.s.
The parking area will be used as a detention pond. The capacity of this
pond to the high water line of 5010.75 feet is 1650 cubic feet. The historic
outlet rate would require a 2.2 inch diameter pipe. This size of pipe is
very susceptible to plugging from trash and leaves, therefore a 3 inch
diameter pipe will be used. The discharge from the 3 inch diameter pipe
will be 0.20 c.f.s. when the pond is full. Until the pond is full the rate
will be less than the 0.20 c.f.s.
The outlet from the pond is to the east which is the parking and access drive
behind the buildings in Parkwood East, which drains to the Southmoor Village
drainage channel. Our runoff to this project is the same for the two year
storm and less for the 10 year and 100 year storms, and will not impact this
project.
Franklin D. Blake, P.E. & L.S.
7839
AW
06OMPUTATIONS
James H. Stewart & Associates, Inc. 214 N..Howes St.. Ft. Collins, CO 80521 (303) 482-9331
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lames H. Stewart & Associates, Inc. 214 N..Howes St.. Ft. Collins, CO 80521 (303) 482-9331
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James H. Stewart & Associates, Inc. 214 N. Howes St. Ft. Collins, CO 80521 (303) 482-9331
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