HomeMy WebLinkAboutSite Certifications - 12/05/1996 (12)wO�
AIRES
ASSOCIATES b� C
December 5, 1996 Avg
Mr. Basil Hamdan
City of Fort Collins Stormwater Utility
235 Mathews Street
Fort Collins, Colorado 80522
Re: =BtO Tire.Store Drainage Certification
Dear Basil,
On December 4, 1996, our surveyors obtained as -built elevations at important locations around
the above -referenced project site. I have included a map showing the elevations obtained
during the survey.
In most cases, the as -built elevations are within 0.1-foot of the design elevation. Where.there is
a greater deviation (near the transformer on the island at the east end of the project), the
intended drainage patterns are still realized. The gutter flowline slopes generally exceed the
design slopes, although there is an. exception at the northwest corner of the project. The design
slope of the gutter is 0.5% but the as -built slope is 0.44%. This should not have an adverse
impact, however, because the building is 1.5 ft higher than the flowline (the contributing area
[hydrologic] is extremely small and should not result in flows large enough to cause flooding of
the building near this flatter gutter section)., The finished first -floor elevation matches the design
elevation.
The only instance of deviation from the intended drainage pattern occurs in the swale running
east -west along the north side of the project. The grading plan shows flow arrows running east
for the entire length of the. swale. This is impossible when considering City standards. The
maximum possible slope for the swale is 0.22% (based on the existing back -of -walk elevations
at the west and east ends of the swale), which is flatter than allowed. The as -built elevations
show that a high spot was created at the approximate mid -point of the swale, providing positive
drainage in the west and east directions.
The design grading plan did not include any storm drain pipes, inlets, swale cross sections, or
erosion control measures, and thus none of these items are certified by this letter. If you have
any questions or comments, or need additional information, please don't hesitate. to call.
Sincerely,
Iociates, Inc.
lt Qu en, P.E.
Civil Engineer
SQ:sp
Enclosure
cc: Freddy Kiefer, Sinnett Construction
Owen Ayres & Associates, Inc.
Engineers/Scientists/Surveyors
3665 JFK Parkway, Building 2, Suite 300, P.O. Box 270460, Fort Collins, CO 80527 HAM
(970) 223-5556, Denver Metro (303) 572-1806, FAX (970) 223-5578 34-0 2 423.00
.00
Printed on recycled paper
STORMWATER
AVMS
ASSOCIATES
December 5, 1996
Mr. Basil Harridan
City of Fort Collins Stormwater Utility
235 Mathews Street
Fort Collins, Colorado 80522
Re: v_Big=O Tire -Store -Drainage -Certification
Dear Basil,
RECEIVED
JAN 17 1997
I
U
On December 4, 1996, our surveyors obtained as -built elevations at important locations around
the above -referenced project site. I have included a map showing the elevations obtained
during the survey.
In most cases, the as -built elevations are within 0.1-foot of the design elevation. Where.there is
a greater deviation (near the transformer on the island at the east end of the project), the
intended drainage patterns are still realized. The gutter flowline slopes generally exceed the
design slopes, although there is an exception at the northwest corner of the project. The design
slope of the gutter is 0.5% but the as -built slope is 0.44%. This should not have an adverse
impact, however, because the building is 1.5 ft higher than the flowline (the contributing area
[hydrologic] is extremely small and should not result in flows large enough to cause flooding of
the building near this flatter gutter section). The finished first -floor elevation matches the design
elevation.
The only instance of deviation from the intended drainage pattern occurs in the swale running
east -west along the north side of the project. The grading plan shows flow arrows running east
for the entire length of the swale. This is impossible when considering City standards. The
maximum possible slope for the swale is 0.22% (based on the existing back -of -walk elevations
at the west and east ends of the swale), which is flatter than allowed. The as -built elevations
show that a high spot was created at the approximate mid -point of the swale, providing positive
drainage in the west and east directions.
The design grading plan did not include any storm drain pipes, inlets, Swale cross sections, or
erosion control measures, and thus none of these items are certified by this letter. If you have
any questions or comments, or need additional information, please don't hesitate to call.
Sincerely,
O� en AyrA & Associates, Inc.
----- -- --.., . ._.
Civil Engineer
SQ:sp
Enclosure
cc: Freddy Kiefer, Sinnett Construction
Ov:=;; gyres & Associates, Inc.
Engineers/Scientists/Surveyors
3`65 JFK Parko:ay, Building 2, Suite 300. P.O. Box 270,60. For. Collins. CO 30527 HAMD-121TR
(970) 223-5556. Denver Metro (303) 572-1806, FAX (970) 223-�;576 34-0423.00