3. Mitigation InitiativesChanhassen 2005 Alternative Urban Areawide Review 2016 Update
MITIGATION INITIATIVES
Mitigation Plan. The final AUAR document must include an explicit mitigation plan. At the RGU's
option, a draft plan may be include in the draft AUAR document;of course, whether or not there is
a separate item for a draft mitigation plan, proposed mitigation must be addressed through the
document.
It must be understood that the mitigation plan in the final document takes on the nature of a
commitment by the RGU to prevent potentially significant impacts from occurring from specific
projects. It is more than just a list of ways to reduce impacts—it must include information about
how the mitigation will be applied and assurance that it will. Otherwise, the AUAR may not be
adequate and/or specific projects may lose their exemption from the individual review.
The RGU's final action on the AUAR must specifically adopt the mitigation plan; therefore, the
plan has a "political"as well as a technical dimension.
This Mitigation Plan identifies initiatives that address potential impacts resulting from future
development within the AUAR Project area. This mitigation plan specifies the controls,
procedures, and other steps that may be implemented to protect or minimize potential negative
impacts. In order to mitigate the potential environmental impacts identified in the Chanhassen
AUAR, The City of Chanhassen will commit to implementing the mitigation initiatives identified in
this plan.
Intent of Mitigation Plan
New development generates impacts on the environment and on existing development. These
impacts result from construction activities associated with new development (i.e. erosion, dust,
noise)as well as post construction associated with the activities and design of the development
i.e. traffic, runoff, pollution, infrastructure demand). This plan identifies existing tools and policies
that the City of Chanhassen has in place to address the types of impacts that may result through
development of the Chanhassen AUAR project area. The plan also identifies additional initiatives
that will need to be implemented to mitigate potential environmental impacts resulting from
projected development of the project area.
There are multiple ways in which Mitigation Initiatives may be implemented such as:
o Enforcing existing zoning and subdivision ordinances and other development
regulations at the time of development concept submittals, preliminary and
final platting, and during construction monitoring activities;
o Referencing and implementing policy directions during the review and
approvals of development projects;
o Facilitating additional study as regional transportation planning initiatives
become more finalized or as other regional developments alter travel
patterns/behaviors.
o Planning and building public infrastructure (local roads, parks, trunk sewer
systems and water systems) in conjunction with private development
initiatives;
o Maintaining and updating of existing plans and studies for the community;
o Requiring additional field work/investigations as part of pre development
planning where potential environmental or cultural resources may exist but
have not been verified.
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General Mitigation Initiatives
This section identifies a series of mitigation initiatives that are general in nature and apply to all
public and private development within the AUAR.
1. All permits identified in the AUAR (See question#8)as well as other necessary permits that
may be required will be secured by the City, or private parties as appropriate,for all
development activities within the project area.
2. The City will follow its own regulations, ordinances, plans, and policies currently in place inthereviewandapprovalofalldevelopmentactivitieswithintheprojectarea. These items
include The 2030 Comprehensive Land Use Plan, the official zoning and subdivision
ordinances and the Bluff Creek Overlay ordinance. In addition, the Bluff Creek Watershed
Natural Resource Management Plan, the Surface Water Management Plan, the
Comprehensive Water Supply Plan, and the Comprehensive Sanitary Sewer System Plan will
be used as technical resources in reviewing development activities and developing
associated public infrastructure.
3. The City will extend public sewer and water services in a manner consistent with existing
plans and policies for delivering trunk sanitary sewer service and water main systems.
Abandonment and closure of individual well and septic systems will follow existing local and
state regulations.
4. The City will work with Mn/DOT and Carver County to periodically monitor traffic as
generated from development within the project area as well as regional development
initiatives that will affect the project area. Performing traffic counts and monitoring traffic
movements will help in facilitating future local roadway improvements.
5. The City will provide for adequate regional and local stormwater ponds and trunk facilities toprotectwaterresourcesandwaterqualityasguidedbytheSurfaceWaterManagementPlan
and the Bluff Creek Watershed Natural Resource Management Plan.
6. The City will to monitor development within the AUAR Project Area and its conformance with
the development scenarios assumed in the AUAR.
7. The City will enforce its parkland dedication practices consistent with the goals and policies
outlined in the 2030 Comprehensive Plan and the Bluff Creek Watershed Natural Resource
Management Plan and the requirements of the subdivision ordinance.
8. The City will follow existing zoning regulations including Floodplain Overlay (Article V),
Wetland Protection (Article VI), Shoreland Management (Article VII), Bluff Protection (Article
XXVIII)and Bluff Creek Overlay (Article XXXI)to protect natural and environmental resources
from potential impacts resulting from the Development Scenario. The City will reference
policies and strategies outlined in the 2030 Comprehensive Plan, Surface Water
Management Plan and the Bluff Creek Watershed Natural Resource Management Plan as
technical resources during the review of specific development projects.
Focused Mitigation Initiatives
Mitigation initiatives that are explicitly intended to mitigate or minimize impacts on a particular
resource or action are outlined by topic in this section.
Fish, Wildlife and Ecologically Sensitive Resources
The Bluff Creek Overlay zoning ordinance contains provisions that require a detailed analysis of
habitat conditions prior to development. This analysis is provided as part of the preparation of
development plans. Staff will verify the findings of the work and will work with developers to
design projects in a manner that protects and preserves these habitat areas. Implementation of
the Bluff Creek Overlay zoning ordinance will protect resources within the Bluff Creek corridor
See Figure 4 Significant Habitat Areas of the AUAR Document.)
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Other areas within the project area maintain significant wildlife or ecologically sensitive resources.
The most prominent resources are identified in Figure 4. The identification of these areas
provides advance notice to developers to plan developments in a manner that protects their
ecological function. The City's 2030 Comprehensive Plan, the Bluff Creek Watershed Natural
Resources Management Plan, the Bluff Creek Overlay zoning ordinance and the Planned Unit
Development (PUD)zoning mechanism (Article VIII) provide the City with the necessary tools to
be flexible with subdivision design in order to preserve these areas. A cooperative approach to
planning and design will be implemented to protect other wildlife and sensitive resources.
In addition to implementing existing plans, policies and regulations, the City will actively work with
non-profit groups focused on preserving quality open spaces and environmental resources that
are identified with this AUAR and future more detailed development planning initiatives.
While there are no instances of high biodiversity or ecological significance directly within the
project area, there are sensitive areas surrounding the site (primarily south of the site and south
of Highway 212)that should be protected from indirect effects (as shown in Figure 5). Initiatives
being implemented within the development area in pursuance with the Bluff Creek Overlay zoning
ordinance are established to prevent or mitigate potential impacts to surrounding environmentally
sensitive sites. In addition, best management practices for site design and storm water
management will be encouraged through the site planning and planned unit development
process.
Water Resources (wetlands, creeks, lakes) and Surface Water Management
Increased stormwater runoff will result from future development in the project area. The Surface
Water Management Plan and watershed regulations establish standards for surface water runoff.
Key policy directives relative to the protection of water resources and the management of surface
water runoff include:
Abstracting the first 1.1-inch of runoff from new impervious surfaces.
Maintaining peak discharge rates at or below current levels.
Providing water quality treatment of runoff prior to discharge from the site or into onsite
wetlands.
Conform to NURP standards.
Remove 60% of phosphorous and 90% of total suspended solids on an annual basis.
Discharge to Lake Susan shall not impair water quality.
Discharge to Bluff Creek shall improve water quality.
Providing pre-treatment for infiltration or filtration practices.
Developing storm water quality and quantity treatment by site or development.
Preparing a Storm Water Pollution Prevention Plan (SWPPP)for each development or
site.
Conformance to NPDES Phase II requirements as outlined in the EPA Clean Water Act.
Additional strategies and policies that direct development in a manner that minimizes impervious
surface coverage are outlined in the 2030 Comprehensive Plan, The Bluff Creek Watershed
Natural Resource Management Plan, the Wetland Conservation Act and the City's Wetland
Protection Ordinance.
Projects within the AUAR that impact wetlands will be subject to regulation under the City of
Chanhassen Wetland Ordinance, Wetland Conservation Act, Chapter 103G Waters of the State
i.e. Department of Natural Resources), and possibly Section 404 of the Clean Water Act (i.e. the
U. S. Army Corps of Engineers). Should wetland impacts be part of a project within the AUAR
these regulatory programs have sequencing requirements which require applicants to
demonstrate that wetland impacts have been avoided and minimized to the extent practicable
and if impacts cannot be avoided these programs require replacement of wetlands impacted by
fill or excavation.
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Erosion and Sedimentation
The City of Chanhassen utilizes "Best Management Practices"as outlined in various resources
and by the Metropolitan Pollution Control Agency(MPCA). During construction activities and prior
to the maturing of vegetative cover over disturbed ground, proper techniques will be used to
control erosion and sedimentation. The City's existing code provides the regulatory tools for this
initiative. Land use management and zoning tools (PUD, density transfers, Bluff Creek Overlay)
will be implemented to direct development to less erosion prone areas of the site.
Wastewater
The development scenarios identified in this AUAR are consistent with the City of Chanhassen
2030 Comprehensive Sanitary Sewer System Plan. The City of Chanhassen through its site
development plan review process will monitor and verify estimated wastewater flows for general
conformance to the Plan. In addition, each development will be responsible for the following:
Conformance to the City of Chanhassen Comprehensive Sanitary Sewer System Plan.
Metropolitan Council Environmental Services (MCES) Sanitary Sewer Extension
Permit(s)
Sewer Access Charges (SAC) related to their proposed development.
The proportional share of the costs of Trunk Sanitary Sewer Mains.
Construction of local sewer mains to serve the development.
Water Supply
Public water supply has been provided to the study area by the extension of trunk water lines.
The Avienda project will need to install a 12-inch trunk water line from the existing end of Bluff
Creek Boulevard to Powers Boulevard to complete the trunk system. These trunk water lines will
supply water to the development area through a local system of water lines to be constructed as
development occurs. Each development will be responsible for the following:
Conformance to the City of Chanhassen Comprehensive Water Supply Plan.
Minnesota Department of Health permit(s)for the extension of water supply systems.
Water Access Charges (WAC) related to their development.
The proportional share of the costs of Trunk Water Supply lines.
Construction of local water supply lines to serve the development.
Traffic/Transportation Mitigation Initiatives
There are a number of specific traffic/transportation initiatives already constructed to adequately
address potential development impacts. As discussed in the AUAR Question 21-Traffic and
Appendix 5-Traffic Analysis, the mitigation approaches outlined below depend on the remaining
AUAR development growth..
1. Proposed improvements to accommodate the remaining AUAR development traffic
include the following:
a. With the improvements already constructed, the TH 212 interchange at the east
end of the AUAR Development will be able to accommodate project traffic at
acceptable levels of service.
b. Improvements to Audubon Road include adding left-turn lanes on the northbound
and southbound (Audubon Road)approaches to the intersection with Lakeview
Drive.
c. Based on the capacity analysis for Scenario F-2 and F-3, the following
intersections should be monitored for potential signalization (if volumes warrants
are met) as the area develops:
a) Lyman Boulevard &Audubon Road North/NW Quadrant Access
b) Lyman Boulevard & Sunset Trail/NE Quadrant Access
c) Powers Boulevard & Pioneer Trail
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3. When plans for reconstruction of existing roads or construction of new roads are
developed, incorporate design considerations that will mitigate noise impacts. These
design considerations would include landscaping, berming and speed limit controls.
4. Coordinate development of perimeter road connections (such as where a collector
roadway within the project area connects to Audubon, Lyman or Pioneer Trail)with
Carver County, the City of Chaska and adjacent neighborhoods.
5. Ensure subdivisions include plans for Pedestrian and Bicycle movement in and through
the project area as well as linkages to the greater community. Roadway designs will meet
the City's current design standards for on-street and off-street trail connections. The City
will work with Carver County to preserve Right-of-Way(ROW)for off road trails.
Land Use Management Initiatives
The project area is unique because of its topographical features and the Bluff Creek corridor. This
uniqueness poses challenges to development. Efforts to minimize impacts on the Bluff Creek
corridor and to maintain as much of the pristine environmental presence of the site will have to
come from combined public and private actions. The City of Chanhassen is well positioned from a
regulatory position to guide development in a manner that achieves the objectives of the 2030
Comprehensive Plan and Bluff Creek Watershed Natural Resource Management Plan. Specific
strategies that enable the City to achieve these objectives include:
o Transfer of density—this approach to development would enable a developer to
move units within a development project from areas that are desired to be preserved
to areas that are less sensitive. The developer would not loose density in the project
by interjecting a broader mix of units and lot sizes.
o Clustering of housing units—this is a conservation development approach used to
minimize development impacts on adjacent resource areas. Although it is more
widely used in rural developments, it can be used in urban settings to obtain the
same resource protection results. Clustering in an urban setting will also reduce
infrastructure thereby reducing up front and longer term maintenance costs. In
general terms, clustering requires smaller lot sizes, reduced street widths to balance
increased protection areas. This would likely be used in conjunction with a transfer of
density when properties have environmental protection areas and involve a Planned
Unit Development(PUD) process.
As the project area develops, there will be a need for park improvements. The City will use its
existing park dedication policies to help fund these improvements.
Monitoring of Development in the AUAR Area and Future Updates to the AUAR
The AUAR assumes a hypothetical development scenario. Because it is based on assumptions,
it is important that actual development be monitored and compared to the development that was
assumed in the development scenario. Tracking of this development will be done through the
City's existing GIS system. The developer as part of the final plat process will submit electronic
plats consistent with city development requirements in a compatible form to the City's GIS
system. This data will enable the City to maintain an ongoing inventory of platted lots and the
ability to directly tie building permits to the lots so that occupied housing units could be tracked in
the development area. The City's existing GIS system has the capacity to perform this task.
As required by Minnesota Rule 4410.3610 Subpart 7, to remain valid, the AUAR must be updated
if any of the following events should occur:
o Five years have passed since the AUAR and mitigation plan were adopted and all
development within the project area has not been given final approval.
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o A comprehensive plan amendment is proposed that would allow an increase in
development than what was assumed in the development scenario.
o Total development within the area would exceed the maximum levels assumed in the
environmental analysis document.
o Development within any subarea delineated in the AUAR would exceed the
maximum levels assumed for that subarea in the document or is of a different land
use type.
o A substantial change is proposed in public facilities intended to service development
in the area that may result in increased adverse impacts on the environment.
o Development or construction of public facilities will occur differently than assumed in
the development scenario such that it will postpone or alter mitigation plans or
increase the development magnitude.
o New information demonstrates that important assumptions or background conditions
used in the analysis presented in the AUAR are substantially in error and that
environmental impacts have consequently been substantially underestimated.
o The RGU determines that other substantial changes have occurred that may affect
the potential for, or magnitude of, adverse environmental impacts.
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