Fish and other aquatic life require unobstructed access to various riparian habitats as well as Lake Michigan to reproduce, grow, feed and survive. In a productive ecological system, fish and aquatic life can move freely up and down rivers and streams—and from rivers and streams to wetlands and floodplains— and from rivers and streams to Lake Michigan - to fulfill critical life cycle needs. This freedom of movement is critically important on watersheds connected to Wisconsin’s Great Lakes.

The watershed downstream of Ozaukee County is highly urbanized and little of the formerly-abundant wetland and riparian habitat remains in its natural state. In-stream habitat has also been significantly altered in many locations for navigation, development and drainage purposes. Therefore, the lower river and estuary have experienced reduced native species abundance and diversity.

In contrast, the upper watershed in Ozaukee County has significant areas of relatively high quality spawning habitat for native species. Until recently, access to these areas was fragmented by large dams and other impediments. Since many freshwater fish move long distances for life-cycle functions, these areas can provide habitat suitable for spawning and juvenile development if hydrologically connected.

The program addresses human activities that can directly or indirectly create impediments that fragment aquatic connectivity and inhibit access to these high quality habitats. Impediments include dams, improperly placed or sized culverts, reaches of invasive vegetation, log and debris jams, pervious fill deposits, straightened, incised and disconnected stream channels, and artificially armored shorelines.