HomeMy WebLinkAboutCorrespondence: Kimley-Horn Minimum Cover Waiver Request
Suite 2125
205 W. Wacker Drive
Chicago, IL
60606
August 23, 2012
Gary Duncan
Assistant City Engineer, City of Carmel
One Civic Square
Carmel, IN 46032
(317) 571-2441
Re: Olive Garden Restaurant – 10206 Michigan Rd., Carmel IN
Minimum Cover Waiver Request
Dear Mr. Duncan:
Per the City of Carmel Stormwater Technical Standards Manual Section 501.01, “There should be
no less than 2.5 feet of cover along any part of the pipe from final pavement elevation or final
ground surface elevation to the top of the pipe.”
Due to site constraints, cover on the proposed storm sewer in some areas within the site do not
meet this 2.5 foot of cover requirement. Cover over all storm sewer pipes exceeds 2.5 feet at all
pavement locations (the majority of storm sewer pipe length). The cover drops below the
minimum 2.5 foot requirement as the storm sewer meets the storm sewer structures located
within the proposed vegetative swale BMP areas. These structures are at lowest elevations
onsite. In order to provide City required BMP for storm water these structures are required to be
within the vegetative swales.
Another site constraint is the City requires a 4 foot maximum ponding depth for detention areas.
We do meet this requirement, and in meeting this requirement, the pond inlet structure
elevations are set, therefore we cannot lower the pipes any more than they currently are. In
addition, the existing 14” sanitary forcemain onsite which the storm sewer must cross constrains
the storm sewer elevations as well.
While site constraints prevent full compliance with Section 501.01 of the Stormwater Technical
Standards Manual, we are providing 2.5 feet of cover over a majority of the storm sewer. Therefore, we
respectfully request a waiver of the minimum cover requirement.
Sincerely,
Kimley-Horn and Associates, Inc.
Justin Muller, P.E.
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