07-22-1991 Council Packet - Laserfiche WebLink

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to be flexibnity in the shoreland ordinances to preserve these historical uses and allow them to redevelop, subject to DNR approval and appropriate environmental protection for the lake. All the cities surrounding the lake face differing circumstances and have their own land use perspectives. Differences in use, density, building heights and other asp^ts subject to shoreland standards will have to be worked out with the DNR dur ;*g the time each city’s ordinance is developed. The cities and MCWD will also need to develop controls for other sources of phosphorus such as ^cessive and/or improper use of phosphorus fertilizers, disturbance of highly erodible areas, filling of wetlands and poor agricultural practices in the basin. Expensive in-lake treatment methods may 5e needed to help maintain water quality, if mur icipal land use controls prove inadequate. The aquatic weed Eurasian Watermilfoil has become established in all parts of Lake Minnetonka and represents a threat to traditional recreational use patterns on the lake. The weed may also cause depletion of dissolved oxygen in the lake during periods when the plants die and decompose, which may adversely impact fish populations as dissolved oxygen is the form of oxs-gen that fish "breathe". Wetlands Two other areas of environmental focus in this plan are directly related to water quality. They are wetlands and fisheries. Water quality cannot be protected unless there is an aggressive wetland protection program for the lake and throughout the upper basin, as wetlands help to control both the rate and quality of runoff reaching the lake. Many wetlands have been lost in the last few decades as the result of development in the Lake Minnetonka watershed. The shoreline of Lake Minnetonka and adjacent wetlands have undergone intense development over the years. As demand grows for additional lake access and redevelopment of residential and commercial districts, the pressure to alter wetland areas is likely to increase. The dredging of channels in Lake Minnetonka for navigational access through wetlands Is an activity that impacts wetland environments and their functional value in managing runoff. While the U.S. Army Corps of Engineers (CoE), DNR, the MCWD and most of the lakeshore communities have regulations or ordinances that control the use of wetlands in and near Lake Minnetonka, additional management tools are needed. All wetlands in the basin need to be surveyed, mapped and evaluated for ‘heir uniqueness and their importance to the water quality and cco-systcm of Lake Minnetonka. I •itification and acquisition (or permanent easement) of the most important wetlands would protect the natural environment and maintain the quality of the recreational experience. Fjtntic Ptontt and Animals The aquatic weed Eurasian Watermilfoil has become established in all parts of Lake Minnetonka and represents a threat to traditional recreational use patterns on the lake. The weed may also cause depletion of dissolved oxygen in the lake during periods when the plants die and decompose. The infesution of the exotic plant, purple loosestrife, in wetlands in the Lake Minnetonka area has the potential to adversely affect the wildlife habitat value of the wetlands. The plant aggressively displaces the native wetland vegetation required by wildlife, while having no value for wildlife itself. Loosestrife has been a noxious weed in Minnesota. WTule state law says that it is the responsibility of landowners to eradicate the plant on their land, most landowners lack the knowledge 7/1 1 Draft - 3