5.9 Summary

The following tables summarize the proposed implementation action items and their relationship to the problems and issues identified in Section 3.0 above, the metrics by which the District will be evaluating progress toward resolving those issues and problems, the estimated District cost of implementing these actions, and anticipated implementation schedule.

Table 17.  Problems and issues identified in the Lake Virginia subwatershed and actions proposed to address them.

 

Problem or Issue

Actions in Implementation Plan

Degree of Improvement

Water Quality

Lake Minnewashta currently has excellent water quality, although it slightly exceeds the total phosphorus concentration goal established in the HHPLS.   Lake Virginia exceeds its total phosphorus goal, but meets or nearly meets clarity, chlorophyll-a, and Trophic State Index (TSI) goals.   Lake Virginia is listed as an Impaired Water for excess nutrients, and a TMDL study is being completed as a result.  Limited data is available for Tamarack Lake and Lake St. Joe, and no total phosphorus goal was established in the HHPLS.

.

  • A phosphorus load reduction plan for Lakes Minnewashta and Virginia that sets forth actions to reduce loading to meet in-lake P concentration goals.  These actions include an enhanced regulatory program andLGU requirement to reduce phosphorus form existing development.
  • Continue monitoring Lakes Minnewashta and Virginia.
  • Establish goal of no degradation for Tamarack and St. Joe and continue to monitor through the Citizen Assisted Monitoring Program

 

Implementation of all the actions in the phosphorus load reduction plan would theoretically reduce in-lake P concentrations, improve water clarity, and meet District water quality goals.

 

Future development is not expected to significantly impact Lake Minnewashta.  Some developing areas drain to Virginia and Tamarack, and nutrient and TSS loads as well as volume of stormwater runoff are predicted to increase as a result.

  • Rules will be amended to require more stringent pollutant load reduction on new development and redevelopment, including adding a volume management requirement.
  • Would depend on ability of developers to incorporate adequate BMPs on their projects and properly maintain them to sustain removal efficiencies.
  • Cooperatively construct regional infiltration improvements to mitigate impact of new runoff from development.
  • Depends on ability to develop cooperative or collaborative improvements.
 
   

Water Quantity

The City of Shorewood has identified a future need to consider the construction of outlets for two landlocked basins.  Outlets would increase downstream volumes conveying additional pollutant loading to Lake Minnewashta. 

  • LGUs prohibited from outletting these landlocked areas and directed to evaluate strategies for managing water volumes as part of their local water management planning.
  • Completed as LGUs complete their local plans.
 

Development, redevelopment, and reconstruction in the subwatershed is predicted to increase volume of stormwater runoff from the watershed as well as increased nutrient and TSS loads. 

  • Rules will be amended to require more stringent pollutant load reduction on new development and redevelopment, including adding a volume management requirement.
  • Would depend on ability of developers to incorporate adequate BMPs on their projects and properly maintain them to sustain removal efficiencies.
  • Cooperatively construct regional infiltration improvements to mitigate impact of new runoff from development.
  • Depends on extent of problem and ability to develop cooperative or collaborative improvements.
 
   

Increased volumes would have a negative impact on channels and culverts conveying stormwater, increasing erosion potential. 

  • Rules will be amended to require more stringent pollutant load reduction on new development and redevelopment, including adding a volume management requirement.
  • Would depend on ability of developers to incorporate adequate BMPs on their projects and properly maintain them to sustain removal efficiencies.
  • Cooperatively construct regional infiltration improvements to mitigate impact of new runoff from development.
  • Depends on extent of problem and ability to develop cooperative or collaborative improvements.
  • LGUs directed to evaluate these locations as part of their local water management planning.
  • Completed as LGUs complete their local plans.
 
   
   

The HHPLS identified two locations that are predicted to overtop during 100-year or larger events.

LGUs directed to evaluate these locations as part of their local water management planning.

Completed as LGUs complete their local plans.

Wetlands

The subwatershed includes numerous large, Preserve classification wetlands with high to exceptional vegetative diversity or habitat values that should be protected.

  • Key Conservation Areas identified that include high-value wetlands.  Some of these areas are identified as District priorities for continued implementation of the Land Conservation Program, and thus the District would proactively look for opportunities to conserve these resources. The Capital Improvement Program includes funds for Land Conservation Activities.   In all key areas, LGUs are required to include in their local plans strategies for conserving these values.
  • Ongoing effort that is dependant on property owner willingness to pursue conservation, District budget and staff capacity, and LGU plan completion.
  • Rules will be amended to establish management standards based on management classification for impacts to wetlands from development and redevelopment.
  • Implementation of revised rules would help minimize future impacts to the highest-value wetlands while still providing a measure of protection to those that provide mainly downstream resource protection.
 
   

There are a few wetlands with moderate restoration potential in the subwatershed.

  • Wetlands identified as being of high to moderate wetland potential would be managed according to a Manage 1 wetland classification if they have been assessed as a Manage 2 or 3.   This would minimize further degradation that might make future restoration more difficult or costly.

Minimize further impacts to restorable wetlands until such time as projects are developed

Ecological Integrity

Much of the subwatershed is characterized by large open areas of forest, grasslands, and wetlands.  Most of this open area has been incorporated into the Lake Minnewashta Regional Park or the Minnesota Landscape Arboretum.  Wetland and associated upland areas with high ecological value are present and should be conserved and connected to preserve their values, create larger areas of ecological value, and connect existing resources

Key Conservation Areas identified that include high-value wetlands.  Some of these areas are identified as District priorities for continued implementation of the Land Conservation Program, and thus the District would proactively look for opportunities to conserve these resources. The Capital Improvement Program includes funds for Land Conservation Activities.   In all key areas, LGUs are required to include in their local plans strategies for conserving these values.

Ongoing effort that is dependant on property owner willingness to pursue conservation, District budget and staff capacity, and LGU plan completion.

All four lakes are home to good to average quality fisheries, and water quality and vegetation management should be considered to maintain or improve those fisheries

  • Support the fisheries through improvement of water quality, management of aquatic vegetation where internal load management is required, and the promotion of shoreline restoration.
  • Work cooperatively with the DNR to manage fisheries

Depends on response of natural system to improved water quality

Eurasian watermilfoil is a concern in both Lakes Minnewashta and Virginia.  Because Lake St. Joe and Tamarack have limited access, they are at lower risk of infestation by that invasive species.  Some curly leaf pondweed has been found in Minnewashta, increasing the need to monitor that lake for the potential in the future to control that invasive species

Plan includes updating aquatic vegetation surveys and development of aquatic vegetation management plan.

Completion of these plans would provide a plan for future activities by the District, LGUs, DNR, lake association, and other interested parties.

Corridor connections between Key Conservation areas should be conserved, enhanced and restored through District efforts as well as local planning.  The corridor functions to provide connectivity between resources in the subwatershed.

Key Conservation Areas identified that include high-value wetlands.  Some of these areas are identified as District priorities for continued implementation of the Land Conservation Program, and thus the District would proactively look for opportunities to conserve these resources. The Capital Improvement Program includes funds for Land Conservation Activities.   In all key areas, LGUs are required to include in their local plans strategies for conserving these values.

Ongoing effort that is dependant on property owner willingness to pursue conservation, District budget and staff capacity, and LGU plan completion.

 

The FAW concluded that most of the larger wetlands in the subwatershed were discharge or combination discharge/recharge.  Opportunities to increase infiltration in the developed areas as well as developing areas should be explored to preserve that hydrology.  A small groundwater-dependent tamarack swamp is present as part of a larger wetland complex at the Landscape Arboretum

  • Amend rules to require pretreatment of stormwater discharged to wetlands or infiltration areas in the areas of high aquifer sensitivity.
  • Establish a new District rule that requires an additional level of analysis and review of permitted development and redevelopment where there is a potential for development to adversely impact groundwater connected to a surface water feature.
  • Work cooperatively with the Landscape Arboretum to evaluate the tamarack swamp for indications of changing groundwater conditions.

Will help minimize future impacts to groundwater and provide for proactive management rather than reactive

Groundwater

There are numerous areas of high to moderate aquifer sensitivity in the subwatershed.

  • Amend rules to require pretreatment of stormwater discharged to wetlands or infiltration areas in the areas of high aquifer sensitivity.
  • Establish a new District rule that requires an additional level of analysis and review of permitted development and redevelopment where there is a potential for development to adversely impact groundwater connected to a surface water feature.

Will help minimize future impacts to groundwater and provide for proactive management rather than reactive

Stormwater management should be coordinated with wellhead protection plans.

Stormwater and groundwater management within those areas will be coordinated with wellhead protection plans.

Will help minimize future impacts to drinking water and provide for proactive management rather than reactive

Table 18.  Summary of metrics to be used in evaluating progress toward Lake Virginia subwatershed goals. 

Objective

Metric

Existing

Desired

Location

Water Quality

Phosphorus Loading (lbs annually)

454

(Ultimate)

341

Lake Minnewashta

Phosphorus Loading (lbs annually)

443

(Ultimate)

397

Lake Virginia

Water Quantity

Volume Reduction (Acre-feet)

 

52

Watershed-wide

1.5 year discharge (cfs)

58.2

58.2

Watershed-wide

100 year discharge (cfs)

118.8

118.8

Watershed-wide

Ecologic Integrity

Key Conservation Areas conserved (acres)

 

33

Watershed-wide

Wetlands

Wetland Acreage

1,455.2

1,455.2 or greater

Watershed-wide

296.2

296.2 or greater

Preserve

213.0

213.0 or greater

Manage 1

75.5

75.5 or greater

Manage 2

168.4

168.4 or greater

Manage 3

Table 19.  Summary of Lake Virginia subwatershed implementation program.

Item

Description

Estimated Cost

Schedule

Section 3.0 Problems Addressed

MCWD Capital Projects

1

Regional infiltration

$25,100

2010

3.1.1, 3.1.2, 3.2.1, 3.2.2, 3.3.1, 3.4.1, 3.5.1

$86,600

2012

$70,700

2014

$47,000

2016

MCWD Data Acquisition/Study

1

Identify keystone, umbrella, and indicator species, evaluate habitat, and develop conservation strategies

Part of watershed-wide study

2010 and ongoing

3.3.1, 3.3.2, 3.4.1, 3.4.2, 3.4.3

2

Develop infiltration/filtration strategies appropriate to wellhead protection areas and areas of groundwater sensitivity

Part of watershed-wide study

2008

3.1.2, 3.2.3, 3.2.4, 3.3.1, 3.4.1, 3.4.2, 3..5.1, 3.5.2, 3.5.3

3

Identify manure management and individual sewage treatment system locations

Part of ongoing watershed-wide program

Part of ongoing watershed-wide program 

3.1.1, 3.4.2, 3.5.2

4

Aquatic and shoreline vegetation survey and management plan

 

 

3.4.2, 3.4.3

 

                Minnewashta –
1.  Vegetation management plan 2.  Shoreline erosion survey
3.  Updated vegetation survey 

 

$2,000

$3,000

$8,000

Part of ongoing watershed-wide program

                Virginia
1.  Vegetation survey and management plan
2.  Updated vegetation survey 

 

$7,000

 

$5,000

Part of ongoing watershed-wide program

                Tamarack
1.  Vegetation survey and management plan
2.  Updated vegetation survey 

 

$7,000

 

$5,000

Part of ongoing watershed-wide program

                St. Joe
1.  Vegetation management plan
2.  Updated vegetation survey 

 

$2,000

$5,000

Part of ongoing watershed-wide program

MCWD Land Conservation Program

1

Undertake land conservation efforts in accordance with Figure 19

$496,000

Part of ongoing watershed-wide program

 

MCWD Regulatory Program

1

Amend District Rules to increase stormwater requirements for new development and redevelopment

Part of watershed-wide effort

2007-2009

3.1.1, 3.1.2, 3.3.1, 3.3.2,

2

Amend District Rules to require abstraction of 1? of runoff on  new development and redevelopment

Part of watershed-wide effort

2007-2009

3.1.1, 3.1.2, 3.2.2, 3.2.3, 3.2.4, 3.3.1, 3.3.2, 3.5.1

3

Amend District Rules to adopt wetland management rules based on wetland management classification

Part of watershed-wide effort

2007-2009

3.3.1, 3.3.2, 3.4.1

MCWD Hydrodata Program

1

Monitor Lakes Minnewashta and Virginia

Part of watershed-wide hydrologic data program

Part of ongoing watershed-wide program

3.1.1, 3.1.2

3.2.1, 3.2.2

 

2

Monitor Tamarack Lake and Lake St. Joe through the Citizen-Assisted Monitoring Program

Part of watershed-wide hydrologic data program

Part of ongoing watershed-wide program

3.1.1, 3.1.2

 

3

Identify shallow wells to monitor groundwater levels

Part of watershed-wide study

2008 and ongoing

3.2.2, 3.2.3

3.3.1, 3.3.2

3.4.1

3.5.1

MCWD Education/Communication Program

1

Provide targeted education materials to key stakeholder groups to meet objectives of plan

Part of ongoing watershed-wide program

Part of ongoing watershed-wide program

All

2

Provide educational opportunities for LGU staff, developers, elected and appointed officials and other interested parties

Part of ongoing watershed-wide education program

Part of ongoing watershed-wide program

All

3

Develop and distribute model ordinances and design standards that incorporate low impact design principles

Part of watershed-wide education program

Part of ongoing watershed-wide program

3.1.1, 3.1.2, 3.1.3, 3.2.1, 3.2.2, 3.2.3, 3.3.1, 3.4.1, 3.4.2, 3.5.1, 3.5.2

4

Develop a small grant program to provide financial assistance to property owners desiring to implement BMPs on their property or to install demonstration projects on public property

Part of ongoing watershed-wide program

2008 and ongoing

3.1.1, 3.2.2, 3.3.1, 3.3.2, 3.4.1, 3.5.1

 

5

Promote the development of lake associations for Minnewashta and Virginia

Part of watershed-wide education program

Part of ongoing watershed-wide program

3.1.1, 3.1,2, 3.2.2, 3.3.1, 3.4.1, 3.4.2, 3.4.3

MCWD Operations and Maintenance

1

Inspect Minnewashta Creek channel annually

Ongoing activity

Part of ongoing watershed-wide program

3.1.1, 3.2.1, 3.2.2, 3.2.3, 3.2.4

2

Monitor high vegetative-diversity wetlands for exotic species

Part of watershed-wide education program

Part of ongoing watershed-wide program

3.3.1

Collaborative Projects

1

Work cooperatively with the University of Minnesota to identify potential cooperative projects at the Arboretum that could provide phosphorus load reductions

Part of watershed-wide program

2008 and ongoing

3.1.1

2

Assist the City of Shorewood in the evaluation of proposed outlets from LMC-7 and LMC-8

As requested

As requested

3.1.1, 3.1.2, 3.2.1, 3.2.2, 3.2.3