Water Quality – Lake Independence

Lake Independence is an 851-acre lake located within the municipal boundaries of Independence and Medina.  Over the past several decades, the lake has experienced increasingly impaired water quality that has reduced the lake’s recreational and aesthetic value.  In 2003, the lake was designated as an impaired water body by the Minnesota Pollution Control Agency (MPCA) based on its recent water quality history (MPCA 2002 303(d) list).

To better understand the factors that have been affecting the water quality of Lake Independence, Three Rivers Park District initiated a comprehensive monitoring plan .  Inflow monitoring results and computer modeling identified major sources of pollutants within the Lake Independence watershed and allowed for the characterization of flow volumes, pollutant concentrations, and overall loadings for each inflow site. The primary goal of the study was to develop a list of potential management actions and estimate their associated costs, effectiveness, expected longevity, and technical feasibility based upon the observed field data, computer model predictions, and characteristics of each potential source.

The Lake Independence Diagnostic Feasibility Report identified potential nutrient sources that have contributed to poor in-lake water quality. It was determined that there has been a considerable amount of nutrient loading from the watershed as well as an in-lake internal loading component.  The study identified several best management practices (BMPs) that could be implemented to improve the lake’s water quality.

In 2004, Three Rivers Park District and the Commission met with the Minnesota Pollution Control Agency (MPCA) to begin the TMDL process.  (A TMDL is the sum of the allowable loads of a single pollutant from all contributing point and nonpoint sources that a waterbody can receive and still meet water quality standards.) The Feasibility Report forms the basis of the TMDL project. A work plan is developed before entering into a contract with MPCA and a final report is sent to MPCA when the project is completed.  The final report includes an assessment of the lake, a description of project activities and results, a plan for the allocation of pollutant loads, a public outreach plan, and an implementation plan to achieve and maintain water quality standards. 

A Stakeholders Committee comprised of representatives from the Lake Independence Citizens Association, the Cities of Independence and Medina, the Independence Horse Owners Association, Medina Horse Association, the Pioneer-Sarah Creek Watershed Management Commission, Three Rivers Park District, Hennepin County Environmental Services, agricultural producers in the watershed, and at-large citizens met to develop the work plan and determine water quality goals for the lake.  

The Committee agreed that reductions from six phosphorus sources were needed to achieve the water quality goal of 36 ppb (parts per billion), a reduction of 23% in the current nutrient loading to the lake.  Those sources were identified as agricultural cropland, animal waste, urban development, failing individual sewage treatment systems, the Loretto Sewage Treatment Facility, and geese. 

Following a public meeting in September 2005, the Cities of Independence and Medina, the Stakeholder Committee, Three Rivers Park District, MPCA, and the Commission met to discuss the waste load reduction allocations, determine what BMPs are financially and socially acceptable, develop a time line for implementation, and discuss potential funding sources and the consequences of non-compliance.

In September 2006, MPCA requested comments on the draft TMDL Report for the Lake Independence.  The final Lake Independence TMDL work plan was submitted to MPCA and the Board of Water and Soil Resources on February 26, 2007.  The TMDL is published in two formats – the version approved by the Environmental Protection Agency dated January 2007 and the March 12, 2007 version that includes the expanded Implementation Plan.

MEP Grant Funds Shoreline Protection

In 2005 the Pioneer-Sarah Creek Watershed Management Commission received a MetroEnvironmental Partnership (MEP) Grant from Metropolitan Council. Submitted on behalf of the Lake Independence Citizens Association (LICA) the grant assists in funding and constructing shoreland protection around Lake Independence.

Funding was used to reduce nutrient inputs to the lake by installing rain gardens and lakeshore stabilization.

Commission Staff identified four potential project sites.  They were prioritized based on water quality improvement potential and public visibility. 

Projects were funded on a 75% cost basis, with homeowners providing a 25% in-kind or cash contribution.  The total amount available from the grant was $24,500 (75% cost share) and in-kind and cash totaled $29,788.  

The purpose of the MetroEnvironment Partnership Grant Program is to improve the water quality of metro area lakes and rivers by reducing nonpoint source (NPS) pollution through education and implementation grants.  NPS pollution is a major contributor to water quality problems in area streams, rivers, and lakes.

In 1998, Metropolitan Council and the Minnesota Center for Environmental Advocacy (MCEA) entered into an agreement designed to focus on abating nonpoint sources of pollution to area waters.  As part of that agreement, the MEP program was established to provide grants to address NPS pollution planning, education, and remediation.  The MEP grant program ended in 2005.