Undermining of old growth red pine trees at Songo Beach, Sebago Lake State Park, due to beach erosion and recession from recent lake-level management. During the summer, this natural beach is almost completely underwater. This occurred only rarely prior to the late 1980s. Photo taken November 2001.

3. Analysis of impacts of lake-level management on sand beach ecosystems of Sebago Lake.

FOSL requests that FERC include in its EIS an evaluation of the reduced ability of the beaches of Sebago Lake to filter organic material from the water. It is quite clear that much beach area has been lost to flooding, erosion or has been converted to rip-rap.

An evaluation of the amount of beach area lost or altered needs to quantified in the EIS, including a comparison of the amount of sandy beach area that existed prior to 1987 and the amount of sandy beach area today. The comparison should be based on average beach area and for the warm months of May, June, July and August.

FOSL recognizes that the beaches and sandbars of Sebago Lake are a great natural freshwater water filter. A cubic meter of beach sand of an average grain size of .025 mm and 38 percent porosity has a surface area of 2.5 hectares. This surface area is coated with meiofauna and bacteria (McLachlan and Erasmus 1983).

The meiofauna is adapted to removing the organic material in suspension in the water column. The high wave energy of Sebago Lake is the engine that pumps vast amounts of water through the beach sands. In recent years, some of the natural beaches of Sebago Lake have completely disappeared during the summer months. Shorefront owners have been forced to cover beaches with rip-rap to protect their houses. An example of this is the Portland Water District rip-rapping of the south shore of the lake along Route 25 in Standish.

This filtering capacity is even more important in lieu of the high and stable water level regimes now in effect in tributary ponds like Thomas Pond and Panther Pond. The State of Maine has mandated that state controlled dams on lakes should be managed for a high and stable water level whenever possible throughout the year. This type of lake level management means that organic nutrients in the lake do not have the chance to oxidize and be reduced by exposure to the air. This type of management has a very adverse effect on the ecology of a lake or lake wetland. The Sebago Lake tributary rivers and ponds have exhibited increased growths of aquatic plants in recent years. This is one more reason why it is very important that the resilience of the filtering capacity of Sebago Lake beaches be protected by the implementation of water levels which are ecologically sound.

Sebago Lake has the potential for many outstanding rated beaches along with a multitude of good beaches. With the large fetches of open water beaches are subjected to wave action from small to large many days of the year. The condition of this sandy beach ecosystem has not been analyzed in recent FERC relicensing proceedings (FERC 1997). Because of the vastness of Sebago Lake beaches and the typical wave actions, FOSL believes comparison to the ocean sandy beach ecosystem is proper. See McLachlan and Erasmus (1983): "The marine fringe provides a vast area of cleansing filter for the oceans which has been used since the advent of micro-organisms. Sandy beaches are "great digestive and incubating systems'" (Pearse et al. 1942) with 'self purifying and self regulating abilities' (Cliff et al. 1970)."

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