Presumpscot River / Main Stem Watershed
Location:
The Presumpscot River / Main Stem watershed is the longest watershed in the Presumpscot River watershed system system. It extends in a narrow swath along either side of the Presumpscot River -- over 25 miles from its start at the outlet of Sebago Lake to Casco Bay.
Size:
The Presumpscot River / Main Stem watershed is the largest watershed in the Presumpscot River watershed system system. At approximately 37 square miles; it makes up 18% of the Presumpscot River watershed system.
Population:
The Presumpscot River / Main Stem watershed also has the largest population, by far, at 26,000, or approximately 41% of the population in the Presumpscot River watershed system.
Impervious Surfaces:
Impervious surfaces are those surfaces in the landscape that cannot infiltrate rainfall, such as rooftops, pavement, sidewalks, driveways and compacted earth. Impervious surface areas of 10% or greater are often correlated with reduced water quality. Approximately 12% of the Presumpscot River / Main Stem watershed, nearly 3,000 acres, is comprised of impervious surfaces.

