Letter from Chip Hentges 11-21-06
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219 East Frontage Road
Waconia, MN 55387
Phone: 952-442-5101
Fax: 952-442-5497
CONSERVATIOII DISTRICT
htto:/Iwww.co.carver.mn.us/SWCD/SWCDmain.html
Mission Statement: To provide leadership in conservation and teach stewardship of the soil, water, and related
resources throu~h a balanced, cooperative pro~ram that protects, restores, and improves those resources.
April 21, 2006
Robert Generous
City of Chanhassen
7700 Market Boulevard
Chanhassen, MN 55317
Re: Autobahn Motorplex
Mr. Generous:
The SWCD has taken the opportunity to review the Autobahn Motorplex. Please review and
consider the following comments and suggestions regarding the SWPPP and erosion control and
sediment controls.
SWPPP
1 - A Storm water pollution preventive plan (SWPPP) will need to be developed for the site and
approved prior to issuing a permit. Our office would like to receive and review the SWPPP once
it is developed and comment for the city.
Erosion Control
1. It should be noted on the plan that energy dissipation is needed on all inlets and outlets
within 24 hours of installation.
Sediment Control
1. Curbside inlet control were identified on the plan, but it should be noted that other proven
methods are out there that work better. (Hay bales are not a proven method) Wimco-
type, or other comparable inlet controls should be used and installed within 24 hours of
installation of the inlets.
2. The proposed temporary storm water ponds needs a detail showing a temporary outlet for
these ponds. Also, how will water reach the storm water pond during construction - it
should be noted that all areas should be positive graded to the storm water pond.
3. All perimeter controls that will be placed need to follow the cities specification in
specific areas. The perimeter controls should be inspected by the city and the SWCD
prior to grading.
4. Temporary seeding of stockpiles will be required ifleft exposed for more than 14 days -
these requirements will need to be spelled out in the SWPPP.
AN EQUAL OPPORTUNITY EMPWYER
Storm water Management
1. An adequate easement for pond access for maintenance purposes is needed and
should be shown on the plan.
I would like to be invited to the Pre-con meeting prior to starting the project to be introduced to
the players of the project.
If there are any questions or if I can be of further assistance please contact the SWCD office.
Sincerely,
Chip Hentges
Conservation Technician
c. Lori Haak, City of Chanhassen (email)