5.9 Summary

Following tables summarize the proposed implementation action items, 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.

 

Problem or Issue

Actions in Implementation Plan

Degree of Improvement

Water Quality

The water quality in Dutch Lake in in the C-D grade range. Based on this monitoring history, Dutch Lake’s water quality is not supportive of swimming.

·  A phosphorus load reduction plan for Dutch Lake that sets forth actions to reduce loading to meet in-lake P concentration goals. These actions include an enhanced regulatory program, LGU requirements to reduce phosphorus form existing development, and capital projects to reduce internal and external loads.

·  Continue monitoring Dutch Lake.

·  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.

·   

Phosphorus loading reductions would be necessary to achieve any of these desired in-lake phosphorus concentrations. The HHPLS and modeling performed for this plan also noted that internal loading and possibly phosphorus export from wetlands in the subwatershed were likely significant sources of excess phosphorus in the lake

·  A diagnostic and feasibility study assessing sources of pollutant loading, and capital projects to reduce internal and external load sources.

·  Would depend on outcome of diagnostic and feasibility of implementing improvements.

·   

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.

·  Cooperatively construct regional infiltration improvements to mitigate impact of new runoff from development.

·  Would depend on ability of developers to incorporate adequate BMPs on their projects and properly maintain them to sustain removal efficiencies.

·  Depends on extent of problem and ability to develop cooperative or collaborative improvements.

Water Quantity

Dutch Lake currently experiences fluctuations in water levels due to beaver dams and other obstructions to the outlet.

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

·  Completed as LGUs complete their local plans.

Drainage is conveyed through the subwatershed through a series of culverts that should be evaluated, monitored, and replaced or repaired as necessary to maintain conveyance, minimize erosion, minimize hydrologic bounce, and maintain adequate water levels in lakes and wetlands.

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

·  Completed as LGUs complete their local plans.

The HHPLS identified one locations where the minimum 2 foot freeboard requirement was not met for the 100-year event:, on Game Farm Road.

·  LGUs directed to evaluate these locations 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.

·  Cooperatively construct regional infiltration improvements to mitigate impact of new runoff from development.

·  Would depend on ability of developers to incorporate adequate BMPs on their projects and properly maintain them to sustain removal efficiencies.

·  Depends on extent of problem and ability to develop cooperative or collaborative improvements.

Future development could increase the volume and velocity of discharges conveyed by Dutch Creek.

·  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.

 

The subwatershed includes several Preserve classification wetlands with high to exceptional vegetative diversity, fish and wildlife habitat and aesthetic 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.

Wetlands with high to moderate restoration potential in the Regional Park

·  Work cooperatively with Three Rivers Park District to identify potential retorations.

·  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.

·  An initial effort that identifies for restoration those wetlands that would technically be easiest to restore, and those in Key Conservation Areas that may benefit most from restoration. This would begin to mitigate wetland losses from past development and help to increase the quantity and quality of wetlands present.

Ecological Integrity

Areas both in and outside the Park have been designated as Regionally Significant Ecological Areas. Wetlands with high ecological value are present and those wetlands and associated upland areas should be conserved to preserve their values, create larger areas of ecological value, and connect existing resources. An ecological corridor through the subwatershed should be conserved to span several subwatersheds.

 

·  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 railroad berm that bisects the subwatershed is a barrier to ecological connectivity.

·  Work cooperatively with Hennepin County to identify opportunities to improve ecological connectivity

·  Depends on opportunities and ability to collaborate on improvements.

The Dutch Lake fishery was last surveyed in 1993 and there is no current fish data.

·  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 obtain fishery data.

·  Depends on response of natural system to improved water quality

·  No detailed information is available on aquatic vegetation in Dutch Lake.

·  Conduct aquatic plant surveys as part of internal load management diagnostic and feasibility studies for Dutch Lake.

·  Completion of this survey would fill this data gap.

Groundwater

·  There are areas in the subwatershed that are highly sensitive to aquifer impacts.

·  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

·  The FAW identified several large recharge wetlands in the subwatershed. As development occurs it will be important to maintain hydrology to them to preserve groundwater recharge.

·  Amend rules to require infiltration or abstraction of the first one inch of rainfall on new permitted development and redevelopment.

·  Identify a network of surficial aquifer monitoring wells across the watershed, monitor groundwater levels and quality.

·  Promote Better Site Design (Low Impact Development) principles for new development that mimic predevelopment hydrologic regime.

·  Infiltration on site will assist in preventing further modification of surficial groundwater recharge and help to maintain wetland hydrologic regimes.

·  Wellhead Protection Areas and associated Drinking Water Sensitivity Management Areas have been identified within this subwatershed.

 

·  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 16.  Summary of metrics to be used in evaluating progress toward Dutch Lake subwatershed goals.

Objective

Metric

Existing

Desired

Location

Water Quality

Phosphorus Loading (lbs annually)

724 (Ultimate)

306

Dutch Lake

Water Quantity

Volume Reduction (Acre-feet)

 

59

Watershed-wide

1.5 year discharge (cfs)

44.1

44.1

Watershed-wide

100 year discharge (cfs)

97.2

97.2

Watershed-wide

Ecologic Integrity

Key Conservation Areas conserved (acres)

 

238

Watershed-wide

Wetlands

Wetland Acreage

652.8

652.8 or greater

Watershed-wide

175.6

175.6 or greater

Preserve

228.5

228.5 or greater

Manage 1

102.0

102.0 or greater

Manage 2

13.2

13.2 or greater

Manage 3

Table 17.  Summary of Dutch Lake subwatershed implementation program.

Item

Description

Estimated Cost

Schedule

Section 3.0 Problems Addressed

MCWD Capital Projects

1

Wetland detention pond

$1,608,000

2015

3.1.1, 3.1.2

2

Wetland restoration

$730,100

2013

3.3.2

3

Regional infiltration

$118,200

2010

3.1.1, 3.1.2, 3.1.3, 3.2.4, 3.3.1, 3.5.1, 3.5.2, 3.5.4

$92,900

2011

$40,000

2014

MCWD Data Acquisition/Study

1

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

Part of watershed-wide study

2008

3.1.3, 3.3.1-3.2.5, 3.4.1, 3.5.1

2

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

Part of watershed-wide study

2010 and ongoing

3.4.1, 3.4.2, 3.4.5

MCWD Land Conservation Program

1

Undertake land conservation efforts in accordance with Figure 19

$2,575,0000

Part of ongoing watershed-wide program

3.3.1, 3.3.2, 3.4.1

MCWD Regulatory Program

1

Amend District Rules to increase stormwater management requirements for new development

Part of watershed-wide effort

2007-2009

3.1.3

2

Amend District Rules to require abstraction of 1” of rainfall on new development and redevelopment

Part of watershed-wide effort

2007-2009

3.1.3, 3.2.2-3.2.5, 3.5.1 – 3.5.3

12

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, 3.5.1, 3.5.2,

MCWD Hydrodata Program

1

Monitor Dutch Lake and Dutch Creek

Part of watershed-wide hydrologic data program

Part of ongoing watershed-wide program

3.1.1, 3.1.2, 3.1.3, 3.2.1, 3.2.4, 3.2.5,

2

Identify base level flow in Dutch Creek

Part of watershed-wide study

Part of ongoing watershed-wide program

3.2.4, 3.2.5, 3.5.1

3

Identify shallow wells to monitor groundwater levels

Part of watershed-wide study

2008 and ongoing

3.2.4, 3.2.5, 3.3.1, 2.3.2, 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 watershed-wide education program

Part of ongoing watershed-wide program

3.1.1 – 3.1.3, 3.2.4, 3.2.5, 3.3.1, 3.4.1, 3.5.1, 3.5.2

2

Provide workshops, seminars, and brown bags for LGU staff, developers, and other interested parties

Part of watershed-wide education program

Part of ongoing watershed-wide program

3.1.1- 3.1.3, 3.2.4, 3.2.5, 3.3.1, 3.3.2, 3.4.1, 3.5.1, 3.5.2, 3.5.3

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

3.1.1-3.1.3, 3.2.4, 3.2.5, 3.4.1, 3.5.1, 3.5.2, 3.5.3

4

Promote the development of a Dutch Lake Association

Part of watershed-wide education program

Part of ongoing watershed-wide program

3.1.2, 3.1.3, 3.2.4, 3.2.5, 3.3.1, 3.4.1-3.4.5

5

Recruit and train volunteers to monitor vegetation in Dutch Lake

Part of watershed-wide education program

Part of ongoing watershed-wide program

3.1.2, 3.4.2-3.4.5

6

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 watershed-wide program

2008 and ongoing

3.1.3, 3.2.2-3.2.5, 3.5.1 – 3.5.3

MCWD Operations and Maintenance

1

Inspect Dutch Creek at least annually

Part of watershed-wide program

Part of ongoing watershed-wide program

3.1.2, 3.1.3, 3.2.2, 3.2.4, 3.2.5

2

Monitor high vegetative-diversity wetlands for exotic species

Part of watershed-wide program

Part of ongoing watershed-wide program

3.3.1

3

Maintain detention ponds to sustain removal efficiency

Incorporate into life-cycle cost of project

Part of ongoing watershed-wide program

3.1.1, 3.1.2

Collaborative Projects

1

Cooperative project with Mound and Minnetrista to stabilize Dutch Creek streambanks if necessary

Part of watershed-wide cost-share program

2008 and ongoing

3.1.2, 3.1.3, 3.2.2, 3.2.4, 3.2.5