Mission

The goal of Three Rivers Park District Water Resources Management is to manage the Park District's water resources in cooperation with the surrounding communities and watershed management organizations in a way that is environmentally responsible and that will maintain lake water quality at or above the levels experienced in 1989.

Three Rivers Park District owns all or part of the shoreline of 34 lakes, two rivers, six streams, and hundreds of wetlands in the Twin Cities Metropolitan Area (TCMA). These water bodies constitute a vital part of the natural resources base in the Park District and are an important recreational resource for Park District visitors. In particular, lakes are heavily used by park guests and are a valuable economic resource to shoreline homeowners and local municipalities.

Swimming Beach Management

Three Rivers Park District maintains 10 swimming beach facilities for park guests. The beaches are monitored weekly for E. Coli bacteria levels, swimmer's itch, leeches, and weed and algae problems. Three of the swimming facilities, French Regional Park , Lake Rebecca Park Reserve, and Cleary Lake Regional Park , have beach curtains around them to control nuisance populations of these aquatic organisms. The main problem at most swimming beaches is the large goose populations which have developed over the last few years. Three Rivers Park District staff undertake a number of measures to reduce goose populations including:

• Fence swimming beaches to exclude geese
• Relocate adults and young out of state during the molting season
• Prohibit feeding of geese on swimming beaches
• Herding geese off of beaches with trained boarder collies
• Pick goose dropping off of beaches daily

Swimming Beach Bacteria Guidelines

Well Management

Water Quality Management staff is responsible for providing an adequate supply of safe potable water to park guests and employees from over 50 wells in the Park District. Staff assists the Minnesota Department of Health with monitoring the quality of all wells each spring before water is used by park guests. Problem wells are treated before being opened to the public. In addition, Water Quality staff samples each well twice during the summer to ensure safe drinking water. Three Rivers Park District is implementing a comprehensive program to improve the safety of all wells in the Park System.

Exotic Species Control

Water Quality Management staff is involved in efforts to control the spread of exotic species such as Eurasian watermilfoil, Zebra mussels and curly leaf pondweed within and to Three Rivers Park District's lakes to protect the ecological diversity of water resources. Because it has been found to be almost impossible to eradicate exotic species, Three Rivers Park District current program focuses on managing nuisance growth of the plants in lakes.

Staff coordinates with lake homeowner associations and the Department of Natural Resources to harvest or chemically treat nuisance populations of Eurasian watermilfoil in lakes. The Park District provides an aquatic plant harvester and an operator to the Lake Minnetonka Conservation District, (LMCD), to assist with their milfoil control program on Lake Minnetonka . Three Rivers Park District is an active member of the LMCD Exotic Species Task Force. The focus of this group is to prevent the introduction of exotic species into Minnesota lakes, and to develop cost effective control methods for exotics currently impacting lakes.

Water Quality Monitoring

Three Rivers Park District implements a comprehensive monitoring program to determine the quality of water resources in the Park District. For the past five years, staff has collected samples from 10 lakes including Independence , Spurzem, Rebecca, Medicine, Auburn , Fish, Weaver, Zumbra, and 18 bays on Lake Minnetonka , at two week intervals throughout the summer. The monitoring is done to track water quality trends, and determine if management efforts are successful. The quantity and quality of inflow to lakes is also periodically measured by staff to determine the sources of pollution entering Park District water resources. Monitoring programs are implemented cooperatively with local municipalities, watershed management organizations, and lake homeowner associations. Lake Minnetonka data can be viewed at http://www.minnehahacreek.org . Monitoring data from other lakes sampled by Three Rivers Park District staff will be available soon at this site.

Water Resources staff is currently participating in a unique monitoring program funded by the Environmental Protection Agency. The EPA EMPACT program, (Environmental Monitoring for Public Access and Community Tracking), is designed to provide real-time data over the World Wide Web, and to make the data relevant to Minnesota residents. Three RUSS units, (remote underwater sampling stations), have been installed in area lakes, two in Lake Minnetonka and one in Lake Independence. Data is collected every six hours, stored in an onboard computer, and downloaded to http://www.nrri.umn.edu/empact .

The samples collected from the monitoring programs are analyzed at an in-house water quality laboratory which allows the District to generate accurate and precise water quality data at a very low cost. Three Rivers Park District cooperates with other local water management organizations such as the Elm Creek Watershed Management Commission, the Pioneer-Sarah Creek Watershed Management Commission, the City of Plymouth , the Lake Minnetonka Conservation District, Carver County Environmental Services, and the Minnehaha Creek Watershed District to maximize sampling efficiency.

Pollution Reduction Programs

Most of the lakes in the Park system receive pollutant-laden runoff from developed urban areas. One of these pollutants, phosphorus, causes many problems in lakes, including algae blooms and excessive plant growth. Therefore, a main focus of water quality management efforts is to reduce the amount of phosphorus entering lakes.

Three Rivers Park District staff reviews development plans in areas adjacent to park property and works with local municipalities to minimize impacts to lakes. Water Resources staff develops individual restoration plans to improve lake water quality. Currently, restoration plans for Lake Independence and Medicine Lake are being developed.

In 1996, Three Rivers Park District staff completed a four-year study of the impact of lawn fertilizer on water quality in the Metro area. The study found that although 75 percent of all lawns had very high levels of phosphorus in the soils, phosphorus fertilizer was added to the lawns annually.

The phosphorus concentration in runoff water from these lawns was six times higher than the phosphorus concentration from golf courses. The study found that golf courses were not applying phosphorus to turf areas with very high levels of phosphorus, and as a result, the amount of phosphorus running off was much lower than from residential lawns.

The study found that using phosphorus-free fertilizer could significantly reduce the amount of phosphorus running off of lawns, without hurting the lawns at all. Three Rivers Park District is working with local municipalities to implement phosphorus fertilizer ordinances. To date, Plymouth and Medina have adopted phosphorus fertilizer bans.

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