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Mousam Lake Region Association
Previous Issues Spring - 2003 Newsletter -- Page 3
 

Pages 1
Membership
Winter Inspections
Board of Directors
Newsletter
Coming Events...

Page 2
Annual Meeting
Lake News
Lake Map/Chart
Lake History

Page 3
Lake Enhancement

Page 4
President's Corner

Lake Enhancement
Some facts from the Mousam Lake Phosphorus Control Action Plan summary prepared by Forrest Bell…..

Background
...The large upper basin of Mousam Lake has a relatively slower, near average (Maine average = 1.5) flushing rate (a measure of how often the water in the entire lake is replaced) of 1.3 times per year. In contrast, the smaller and shallower lower basin of Mousam Lake has a much faster flushing rate of nearly 18 times per year.

Long term monitoring has shown a declining trend in water clarity (see graph above right), due in large part to the runoff export of phosphorus that is prevalent in watershed soils. Soil erosion in the Mousam Lake watershed can have far-reaching consequences...Soil particles transport the phosphorus, which essentially “fertilizes” the lake and decreases water clarity. Excess phosphorus can also harm fish habitat and ultimately lead to nuisance algae blooms. Studies have shown that as the water clarity of lakes decreases, lakeshore property values also decline.

Stakeholder Involvement
With these issues in mind, federal, state, county, and local groups have been working together to address the water pollution problem. In 2001, the Maine Department of Environmental Protection funded a project in cooperation with the Maine Association of Conservation Districts and the York County Soil and Water Conservation District to identify and quantify the potential sources of that phosphorus. The report will provide recommendations for additional Best Management Practices to be implemented in the watershed. The final report, completed in April of 2003, is entitled “Mousam Lake Phosphorus Control Action Plan” and doubles as a TMDL report that will be submitted to the United States Environmental Protection Agency, New England Region, for final review and approval.

 What We Learned
A land use assessment was conducted for the Mousam Lake watershed to determine potential sources of phosphorus that may run off from land areas during storm events and springtime snow melting. This assessment involved utilizing many resources, including generating and interpreting maps, inspecting aerial photos, and conducting field surveys.
Results approximate that 1,146 kilograms (kg) of phosphorus per year is exported to Mousam Lake directly from the external watershed. The pie chart (below) depicts the land use-phosphorus load breakdown for the Mousam Lake direct drainage watershed area. Additional indirect phosphorus loads of 247 kg/yr are estimated from the Goose and Loon pond associated sub-watersheds.

The graph (at right) displays the estimate that the external (1,146 kg) + indirect (247 kg) = (1,393 kg) loading exceeds Mousam Lake’s capacity (878 kg) to effectively process phosphorus, which leaves the remaining external watershed load (515 kg/yr) as the approximate amount needed to be reduced on an annual basis to meet the present water quality requirements for Mousam Lake.

What Can You Do To Help?
As a watershed resident or land user, there are many things you can do to protect the water quality in Mousam Lake. Lakeshore owners can use phosphorus-free fertilizers and maintain natural vegetation adjacent to the lake…...Watershed residents can become further involved by volunteering to help the Mousam Lake Region Association and participating in events sponsored by the York County Soil and Water Conservation District. All stakeholders and watershed residents should attempt to learn more about their lake and the many resources available, including the full version of the Mousam Lake Phosphorus Control Action Plan and TMDL study. Draft copies of the combined report are available online at: http://www.state.me.us/dep/blwq/comment.htm, or hard copies can be reviewed at Maine DEP offices in Augusta (L&W Bureau, Ray Building).

Key Terms

Best Management Practices are techniques to reduce sources of polluted runoff and their impacts. BMP’s are low cost, common sense approaches to reduce storm runoff and velocity to keep soil out of lakes and tributaries.

TMDL is an acronym for Total Maximum Daily Load which represents the total amount of a pollutant that a waterbody can withstand and still attain water quality standards.