HomeMy WebLinkAboutRICHIE'S EXPRESS CARWASH - PDP - 15-00 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTC3)
VICINITY MAP
SCALE - 1 "=1000'
j
INC
e
Del Clair Road
Swallow Road
c
oJSITE
�
/
000d
c
e
e
o
I
I
I
.!
230 feet North of the centerline of Foothills Drive. The East gutter runoff in the Frontage Road
flows North to the College Avenue concrete pan across Foothills Drive and then North in the College
Avenue gutter to an existing curb inlet at the existing 48 inch storm drain 230 feet North of the
centerline of Foothills Drive.
EROSION CONTROL:
The site is presently nearly all paved. It is recommended to leave a substantial area of the
existing asphalt for a staging area for the construction of the carwash. At the beginning of the
construction of the curb and gutter, the remainder of the existing asphalt can be removed. This will
allow the site to not be disturbed for a long period of time before the new paving is started. A silt
fence will be placed along the North property line to prevent any silt form entering the bank property.
The water quality extended detention requirement was waived by the City of Fort Collins.
The site plan and grading plan would make extended detention difficult.
The grading and drainage plan is enclosed as a part of this report. The historic and developed
runoff calculations are also a part of this report.
This drainage report and the design of the drainage system are in compliance with the City
of Fort Collins Storm Drainage specifications and criteria. If you have questions regarding this
report, please call.
Sincerely,
6aj'-1,-/r` 96 5 0 28
Richard A. Rutherford, P.E. & L.S...o
RAR/meh R E 4 1..,:'
STEWART86SSOCIATES
April 18, 2000 Consulting Engineers and Surveyors
Mr. Basil Hamdan
Stormwater Utilities
City of Fort Collins
P.O. Box 580
Fort Collins, CO 80522-0580
Dear Basil,
The following is the final drainage report for Richie's Express Carwash which is in the
Foothills Drainage Basin. It is situate in the Southeast 1/4 of Section 26, Township 7 North, Range
69 West of the Sixth P.M., Fort Collins, Colorado.
The site is at 3141 South College Avenue and the existing building is occupied by The Tire
Shoppe. Their building will be demolished and a new carwash center will be constructed on the site.
The site is bounded on the North by an existing bank building, on the East by South College
Avenue, on the South by the Larimer County No. 2 Canal and on the West by Foothills Drive.
The existing site has 94.6% impervious surface and the proposed site has 69.9% impervious
surface. The reduction of impervious surface reduces the two year runoff rate from 3.17 c.f.s. to
2.22 c.f.s. which is a 30% reduction. The 100 year runoff rate is reduced from 14.28 c.f.s. to 10.65
c.f.s. which is a 25% reduction. Therefore there will not be any on -site storrnwater detention
required.
There are three developed sub -basins on the site. Sub -Basin I is a 0.35 acre area that will
drain Northwesterly to the Southeasterly Foothills Drive curb and gutter. Its two year runoff rate
is 0.53 c.f.s. and its 100 year runoff rate is 2.66 c.f.s..
Sub -Basin II is a 1.09 acre area that drains Northeasterly to the existing Frontage Road. Its
two year runoff rate is 1.69 c.f.s. and its 100 year runoff rate is 7.99 c.f.s..
Sub -Basin III is the Larimer County No. 2 Canal and has an area of 0.17 acres. There is no
storm water runoff from this site that discharges into the Canal. The Northerly bank of the Canal is
higher than the site.
The runoff from Sub -Basin I flows Northeasterly in the Foothills Drive gutter to the corner
of Foothills Drive and the Frontage Road. The runoff from Sub-Basin.lI flows North from the site
in the East and in the West gutters of the Frontage Road. The West gutter runoff merges with the
Foothills Drive runoff and flows North across Foothills Drive in a concrete pan and then Northerly
in the West gutter of the Frontage Road to an existing curb inlet at the existing 48 inch storm drain
James H. Stewart
and Associates, Inc.
103 S. Meldrum Street
P.O. Box 429
Ft. Collins, CO 80522
970/482-9331
Fax 970/482-9382
TABLE OF CONTENTS
1-2 Text
3 Vicinity Map
1
' 4-7 Stormwater Runoff Calculations
Pocket Drainage Plan
FINAL DRAINAGE REPORT
FOR
RICHIE'S EXPRESS CARWASH
FOOTHILLS BASIN
PREPARED FOR
THOMAS FRANK
APRIL 18, 2000
PREPARED BY
STEWART & ASSOCIATES
103 SOUTH MELDRUM STREET
P.O. BOX 429
FORT COLLINS, CO 80522
TEL. 970-482-9331
FAX. 970-482-9382