Erosion Shoreline erosion occurs when the land at the lake’s edge is eroded by waves. Shoreline erosion is caused by excessive recreational activity, like boating, which increases the waves present in the lake. The waves grind and displace soil particles leading to sedimentation. Sedimentation carries nutrients and other pollutants attached to the soil into the lake. Soil erosion is harmful because it causes nutrients to accumulate in the body of water which can lead to algal blooms. In addition, the removal of native aquatic and shoreline vegetation that buffers the land from the water, causes the shoreline to further erode. Shoreline erosion leads to a diminished habitat for species. Lakes that receive a lot of sediment can appear cloudy. Check out the picture below to see the erosion occurring currently at Lake Wallenpaupack.
Runoff Stormwater runoff is created when precipitation flows over impervious surfaces such as driveways, parking areas, or roofs and ends up in the lake. As the runoff flows down to the water, it picks up pollutants along the way such as pesticides, metal, or litter. Agricultural runoff occurs when water from farm fields filled with pesticides also flows down into the lake. Stormwater and agricultural runoff thus cause water pollution.
Point Sources The United States Environmental Protection agency defines a point source as “any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged.” Point sources are easy to identify and come from a single place such as municipal wastewater treatments plants to leaky septic systems. Once a point source is identified, it is important to immediately stop the pollutant from further emission when possible. Human activities in the watershed of Lake Wallenpaupack, like fertilizers, road salt, leaky septic systems, and changes in land use, can increase the amount of nutrients in the lake and influence the amount of algae present.
Management and Mitigation Methods The Lake Wallenpaupack Watershed Management District (LWWMD) has included several solutions that can help mitigate shore erosion on the lake. One such solution would be to increase native vegetation cover. Plant roots are the most natural way to maintain a shoreline, and should erosion be taking place, a Best Management Practice (BMP) can be installed to increase native plant growth so their root systems can help maintain the shore's integrity. The LWWMD encourages homeowners to monitor their shorelines for signs of erosion to minimize the runoff of soils and nutrients into the lake. Other management practices can be found from the Pennsylvania Lake Management Society (PALMS). Other than vegetation cover, PALMS also recommends bioengineering techniques to encourage plant growth, as well as simply using stone or riprap to absorb energy from incoming waves. Applications can be filed with PALMS to help with the creation and management of these shore erosion solutions.
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Photo Credits: Christopher J. Michael Jr. Other Sources: