Abstract or Description
Casco Bay and its surrounding watersheds are threatened by increased impervious coverage in urban areas. We used ArcGIS to assign values for percent coverage by impervious surfaces to all watersheds at the HUC 12 level for the Casco Bay region in order to determine which would most benefit from management and restoration. To further pinpoint watersheds at the intermediate level of disturbance, we factored in riparian buffers of 20m around all streams and calculated percent coverage by impervious surfaces within these zones. Total impervious coverage within subwatersheds ranged from 0 to 26% with a mean of 5.7%, while cumulative impervious coverage within 20m of all watercourses in each subwatershed ranged from 0 to 10% with a mean of 1.6%. Our final map highlights ten areas that hover around impairment, defined as impervious coverage of 6% or more: four sites are just above impairment level and six sites are just below. These locations may represent targets for restoration or sustainable management.
Recommended CitationSchneider, Elizabeth and Whalen, Michael "Watersheds on the Brink: Impervious Surface Cover in Casco Bay, ME," Atlas of Maine: Vol. 2012: No. 2, Article 2.
Available at: http://digitalcommons.colby.edu/atlas_docs/vol2012/iss2/2