The Maine Futures Community Mapper focuses on two large watersheds in Maine – one that includes Portland and Lewiston (Casco Bay/Lower Androscoggin); and one that includes Bangor (Lower Penobscot River). These watersheds are slightly larger than Maine counties.┬áBoth watersheds were identified by the Forests on the Edge program of the U.S. Forest Service as being among the top 15 watersheds in the U.S. that were expected to experience major conversions of forest cover to residential land uses (Stein et al. 2005). Later refinements to that study (Stein et al. 2009; White et al. 2009) reduced their U.S. ranking; however, reductions in forest cover of between 5% and 20% are still projected for these two watersheds.

A watershed is an ecological unit or ecosystem containing all land that drains downhill into a river basin. Focusing on watersheds rather than political boundaries like county lines allows us to examine the ecological effects of land use, such as the impact of urbanization on stream conditions.

Casco Bay/Lower Androscoggin and Lower Penobscot watersheds

The two watersheds together cover about 4.5 million acres of Maine. Each exhibits a strong urban-rural gradient extending from Portland (CBLA) and Bangor (LPRW).