Stream Health

Maryland’s Stronghold Watersheds

Stronghold Watersheds are the most important watersheds for the protection of Maryland’s freshwater stream biodiversity. Known as Maryland’s “Stronghold Watersheds”, these locations are the places where Greatest Conservation Need species of stream-dwelling fish, amphibians, reptiles, or mussels have the highest abundance or diversity.​​


Most of these species used to have greater abundance and distribution throughout the State, but now are holding out in these limited areas. Generally, these species are the most sensitive to environmental degradation. A small change in watershed or stream health can permanently eliminate one or more of these sensitive species. As a result, maintaining the health of these watersheds is of critical importance if we are to sustain these species and the vital ecosystem services they provide.