Unified Watershed Assessment
In 1998, to comply with directives of the federal Clean Water Action Plan, Maryland completed a Unified Watershed Assessment that evaluated water quality and living resources conditions in the “eight-digit” watersheds into which the State has been divided. (There were 138 total areas evaluated, but four of them are water only—for landscape assessment purposes, there are 134 of these watersheds.)
Based on both the violation of water quality standards and poor values for other natural resource indicators were used as criteria for determining whether a watershed was classified as “needing restoration”—Category 1—or as being pristine or containing natural resources of very high value and thus needing special protection and conservation—Category 3. Because these watersheds are relatively large, averaging about 75 square miles in size, a single watershed could be classified as being in both categories, and this happened in a few cases. Fifty of the Category 1 watersheds were selected as priorities for restoration action planning and implementation and about 40 were “selected” Category 3 watersheds because they met four or more natural resources goals. These maps represent those determinations.
The Unified Watershed Assessment has guided Maryland’s efforts in developing watershed restoration strategies and plays a role in setting priorities for conservation actions.