Looking Over Sebago Lake

Lake Water Quality

By almost any scientific measure, the quality of Sebago Lake is excellent. For a century, the Portland Water District has been caring for the lake and ensuring its quality for generations to come. Currently, the Portland Water District conducts 10 significant monitoring programs around the lake.

A clean lake benefits everyone. Not only does it remain an excellent public drinking water source, but it is treasured for its salmon and trout fisheries. Tourists flock to the area every summer, and shoreline properties are highly prized.

You don't have to be a scientist to see that the lake is unusually clean - any first time visitor will immediately notice that the bottom can be seen in 30 feet of water. A Secchi Disk is an instrument that measures clarity. It is lowered into the water and the depth at which the disk can no longer be seen is recorded as a measurement of lake clarity. Secchi Disk readings in Maine lakes average between 3 and 8 meters; however, Sebago Lake typically sees 8 to 12 meter Secchi Disk readings.

To learn more about the health of Sebago Lake, view editions of the Watershed News and the State of the Lake Report.

Monitoring Program Reports (Under Publications select Technical Reports for a listing of the most recent editions of the reports below)

Pre 1990 Lower Bay Report

Lake Monitoring Report

Bacteria Report

Periphyton Monitoring Report

Crooked River Report

Tributary Monitoring Report

Tributary Biological Monitoring Report

Common Tests

Environmental scientists monitor the lake for various parameters including temperature, dissolved oxygen, phosphorus, chlorophyll-a, fecal coliform bacteria, MtBE, pH, alkalinity, turbidity, conductivity, total dissolved solids, and water transparency.