HomeMy WebLinkAboutTWIN SPRUCE FARM PUD PRELIMINARY AND FINAL - 22 90 - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTr 1
$ ART&ASSOCIATE
Consulting Engineers and Surveyors
June 6, 1990
Mr. Glen Schlueter
Storm Drainage Utility
City of Fort Collins
P. O. Box 580
Fort Collins, Colorado 80522
Dear Glen:
This is the storm drainage report for Twin Spruce Farm P.U.D. which
is located at 211.5 West Mulberry Street. The area of the site is 2.27
acres net. The site has an existing residence, an existing office and
garage building and an existing greenhouse. The site. is located in the
Canal Importation Basin. It slopes gently from Southwest to Northwest,
And the runoff discharges into the South curb and gutter of West Mulberry
Street.
The site is being reviewed as a Planned Unit Development because
it is proposed to be used as an office as well as a residence. The only
construction that will be done is a "grasscrete" turn around for emergency
vehicles, and two parking spaces.
The runoff coefficient only increases from 0.29 to 0.31 with the
proposed construction. The two-year runoff increases by 0.12 cubic feet
per second which is a 6.7% increase.
Because of this very low increase in runoff, we are requesting a
variance for the requirement of onsite detention. The runoff from the
turn around has approximately 140 feet of grass to flow across before
it would enter the curb and gutter.
We feel this increase of runoff is small enough that there is no
significant adverse effect on the basin. Therefore, we feel the variance
is justified.
The runoff calculations and the site plan are enclosed as a part
of this report.
If you have any questions regarding this site, please call.
Sincerely,
Richard A. Rutherford, P.E. & L.S.;' `�✓ F� ,Qfa
President
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James H. Stewart '.,�j'•; f &
and Associates, Inc. '� ' T' • • .... • •, �`.`
enclosures 214 N. Howes Street
P.O. Box 429
Ft. Collins, CO 80522
303/482-9331
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SUBJECT :L
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PROACTNO.----------
AeisA,
AP- EA = 0, Z, 4- 4c,
P G- P-11 10 VS AP -GA Z-03 Ac-, 89.9
Hisr. C= Q X D&) 4. CO. Z, Y, Of Z I
v tl pep-v toaj a A = 0.31 At:, /.3-7 %
Pc-p-vious Aee-A
t.
Y, /3 7) 4- (6. z 0.31
Tc- = A 87 4-/ 5- '/z-
AVAJ,
Z. -3 VS
V. 7 0- 3 1) + Is-
Z-3 V3 - 2-3 m 1,v,
',2 4 C-F-S,
14 T. X
D ff V, Q -Lyle. = 0. 31 K ?-, 7 A Z - Z7 = b 90 G.F.S.
DEV- 2,5- x 0,31 X 43 x z..?, 7 = 3.78 cF s,