ENG_WRC Memo 3703 South Cedar Drive (ENG)
Memorandum
To: MacKenzie Young-Walters, Associate Planner
From: Erik Henricksen, Project Engineer
CC: Charles Howley, Public Works Director/City Engineer
George Bender, Assistant City Engineer
Date: 10/25/2021
Re: Variance Review at 3703 South Cedar Drive – Planning Case
#2021-25
The Engineering Department has reviewed the variance submittal for 3703 South Cedar Drive.
These comments are divided into two categories: general comments and proposed conditions.
General comments are informational points to guide the applicant in the proper planning of
public works infrastructure for this project, to inform the applicant of possible extraordinary
issues and/or to provide the basis for findings. Proposed conditions are requirements that
Engineering recommends be formally imposed on the application in the final order. Note that
references to the “City Standards” herein refer to the City of Chanhassen Standard
Specifications and Detail Plates.
General Comments/Findings
1. Any and all utility and transportation plans submitted with this application have been
reviewed only for the purpose of determining the feasibility of providing utility and
transportation facilities for the project. A recommendation of variance approval does
not constitute final approval of details, including but not limited to alignments,
materials and points of access, utility connections or discharge, that are depicted or
suggested in the application. The applicant is required to submit detailed construction
drawings for the project, as applicable. The City of Chanhassen Engineering and Public
Works Departments will review plans, in detail, when they are submitted and approve,
reject or require modifications to the plans or drawings based upon conformance with
City Standards, the Chanhassen Code of Ordinances and the professional engineering
judgment of the City Engineer.
2. It is the opinion of the Engineering Department that the proposed variance can be
developed in near accordance with the requirements of the Chanhassen Code of
Ordinances (as it pertains to Engineering and Public Works requirements) and City
Standards, provided it fully addresses the comments and conditions contained herein,
and can be approved.
3. The applicant is requesting a number of variances to facilitate the construction of a
single family home at 3703 South Cedar Drive (Site). These include lot cover, front yard
setback, side yard setback, and shoreland setback variances. Engineering and Public
Works has no comment regarding the front yard and side yard setback variances. There
are no public drainage and utility easements currently on the property and none are
being requested by staff in concert with the variance requests.
4. The applicant is proposing a lot coverage variance. The Site currently has 2,948 SF of
hardcover on the 5,899 SF property, or 50% lot coverage of the Site. The proposed
change to the Site’s total hardcover based on the provided submittals would provide a
reduction of 2.4%, or 137 SF , for a total proposed lot cover of 2,811 SF, or 47.6%. Even
though there is a reduction of total hard cover the Site is still above the allowable lot
coverage (25%) under Ordinance and would require a variance. The proposed reduction
of lot coverage by 137 SF alone would not result in a measurable water quality benefit
to the riparian Site, which is directly adjacent to Lake Minnewashta. Additional
measures must be taken to improve stormwater management, reduce impervious
surfaces on the Site, and to mitigate the amount of stormwater runoff being diverted
into Lake Minnewashta. While it may not be possible to achieve a total of 25% lot
coverage on the Site, the applicant shall submit updated plans that illustrate the use of
pervious paver systems, in accordance with Ordinances (Sec. 20-921), to the maximum
extent possible. The use of pervious paver systems will help reestablish a more natural
hydrologic balance, reduce runoff volume associated with impervious surfaces, all while
providing water quality treatment by reducing the concentration of po llutants. Areas
such as the driveway, sidewalk, and patios should be constructed with pervious paver
systems (an approximate 1046 SF reduction of the proposed impervious surfaces).
Additionally, a permanent 20’ native vegetated buffer must be installed along the
shoreline. The native vegetated buffer will provide additional water quality protections
through filtering pollutants, nutrients and sediments while helping to improve
ecosystem health and function. See proposed conditions 1 and 2.
5. The applicant is proposing a shoreland setback variance. The proposed variance request
is to maintain the existing 40.8 foot structure setback from the ordinary high water level
of Lake Minnewashta. The required setback per Ordinance from the ordinary high
water level in the Shoreland Management District is 75 feet. The applicant justifies that
if there were no variance approved for the shoreland setback that the buildable home
area would equate to about a 75 square foot home, which staff agrees would be a
constrained area. As many of the lots in the surrounding neighborhood have similar
constraints, the City has granted shoreland setback variances to allow for a more
reasonable use of the property. As such, staff recommends approval of the proposed
40.8 foot structure setback as long as proposed conditions 1 and 2 are adhered to in
order to mitigate stormwater runoff being diverted into Lake Minnewashta while
improving the overall health of the ecosystem and function. Lastly, while Engineering
and Public Works is recommending approval of the discussed variances in association
with the proposed conditions, any and all improvements on the Site must meet
applicable jurisdictional requirements. See proposed condition 3.
Proposed Conditions
1. The applicant shall supply updated construction plans that utilize to the maximum
extent possible the use of pervious paver systems in accordance with Sec. 20-921 of City
Ordinances. Areas such as the driveway, sidewalk, and patios must be considered in the
design of these systems.
2. A permanent 20’ native vegetated buffer must be installed along the shoreline using
species native to the ecotype with permanent buffer monuments. The buffer may work
around the path and stairs. The buffer must be designed and installed by an experienced
professional in native shoreline restoration. Design plans must be approved by the
Water Resources Administrator/Engineer.
3. The installation of any improvements on the Site shall meet all applicable jurisdictional
requirements, including but not limited to the Minnesota Department of Natural
Resources and the Minnehaha Creek Watershed District, and all applicable permits shall
be obtained prior to any site improvements.