7-41 Crossings Stormwater Management Summary_2014-10-17
Memorandum
10/17/2014
City of Chanhassen
7700 Market Blvd
Chanhassen, MN 55317
RE: Stormwater Management Plan
7 & 41 Crossings Center
The following is a summary of the stormwater management system for the proposed retail building
project located at the 7 and 41 Crossings Center. The project has been designed to meet the
requirements of the city as summarized in the following paragraphs.
I. Existing Conditions
The current site accommodates the Highway 7 and 41 crossings shopping center. The shopping center
houses a Walgreens store to the northwest, a SuperAmerica gas station to the northeast, and a strip mall
to the south. The remainder of the site is taken up by parking lots and service drives for the shopping
center. The east side of the shopping center contains parking space as well as an area of land that has
been mass graded, and provided with utility services, in consideration for the construction of another
building.
The site currently has stormwater BMP’s that are in place. Runoff from the Walgreens building and
parking lot flows to a rain garden just north of the Walgreens. The SuperAmerica and the strip mall runoff
is captured by storm inlets that feed into an existing storm pond to the south of the strip mall. Runoff
from the proposed building area flows over land, to the west, and eventually into catch basins that are
piped into the storm pond.
II. Proposed Conditions
The new retail building is to be located on the green space to the east of the strip mall parking lot. The
site will contain a 3,915 SF building and a drive-thru lane around the back. A patio area and a new
sidewalk are also proposed to accommodate the site.
Stormwater runoff will sheet flow across the drive-thru lane and into catch basins where it will be piped
into the existing stormwater management pond to the south of the strip mall.