Habitat Restoration

Land use changes in Southeast Wisconsin have greatly diminished the ecological health of rivers and riparian corridors. Stream, wetland, and upland natural habitats are fragmented and degraded, local flooding is exacerbated to the detriment of farmland, homes, and infrastructure, and water quality is diminished, both in the Milwaukee River basin and also downstream along the Lake Michigan coastline. Many rivers and streams were historically dredged and straightened and wetlands destroyed and drained to increase available land and increase agricultural production. Often, the soils excavated in digging the ditch were cast to the sides of the channel, creating levees on both sides that isolate the channel from the floodplain. The lack of recurring overbank flows prohibit floodplain building and the former wetland corridors lack suitable overbank flood flows to sustain a diverse wetland plant and wildlife community. In addition, stream channels are left over-widened with unconsolidated substrate and very poor habitat conditions for fish and wildlife.

The Ecological Prioritization GIS Tool  is used to develop integrated prioritization maps for restoration and preservation to improve the ecological, water quality and hydrologic conditions within streams and riparian corridors, particularly for native fish and wildlife. Tool outputs have identified multiple high-priority projects for maximum ecological benefit in Ozaukee County.

Specifically, the Ozaukee County Planning and Parks Department is completing large scale, comprehensive, holistic habitat restoration projects on Ulao Creek (approximately 2.5 miles), Mole Creek (approximately 1.5 miles), and the Little Menomonee River (approximately 0.25 miles). Construction, restoration, and environmental monitoring activities at all locations are ongoing.

Habitat Restoration Projects: Ulao Creek, Mole Creek, SWWT Wetland Scrape, Little Menomonee River

3 habitat restorations

More Information On the Habitat Restoration Projects:

Ulao Creek
Mole Creek
Sweet Property Wetland Scrape
Little Menomonee River

General Project Goals:

  1. Improve geomorphic function of the project reach(s) by creating a channel that is appropriately sized for its watershed, is connected to a regularly inundated floodplain, and has a self-sustaining, natural meander geometry
  2. Provide high quality, diverse in‐stream and wetland habitat for fish, birds, reptiles, amphibians, and mammals, specifically those that have been identified as species of local conservation interest (SLCIs)
  3. Demonstrate successful use of County-developed GIS Tools (Ecological Prioritization and Fish and Wildlife Habitat) to prioritize and cost‐effectively improve the ecological function of a riparian corridor and adjacent lands for fish and wildlife habitat
  4. Improve water quality in the project areas and in downstream waters by removing pollutants and decreasing erosion risk through stormwater management
  5. Document impacts on water quality through water quality monitoring (continuous and discrete sampling) on the site and within the watershed
  6. Document improvements to the fish and wildlife communities

Project activities and outcomes typically include excavating a stable meandering stream plan form (typical meander length of 7-10 times mean stream width), increase stream length and sinuosity, decrease mean stream width, and increase effective water depths and stream velocities, increase in-stream and bank habitat cover for fish and wildlife, reconnect riparian wetlands, restore and enhance former and existing wetlands in areas of hydric soils, increase canopy shade by planting a diverse selection of native deciduous trees to replace tree canopy, assist with bank stabilization, provide cooling effects for the stream, and combat the spread of invasive vegetation (e.g., reed canary grass), and increase course substrate riffles for lithophilic spawning fish and macroinvertebrates.

Lateral Connectivity and Habitat Restoration Design

Empirical relationships are typically developed to estimate appropriate channel geometry based on analog streams within the region. Streams with relatively flat slopes, similar watershed areas, and a well-developed meander pattern that do not appear to have been intentionally manipulated are analyzed with respect to stream form, including sinuosity, meander wavelength, radius of curvature, and bankfull width to generate hydraulic geometry relationships. Engineering and design also include analyzing hydraulic conditions for a variety of flows, including estimation of peak flow rates, to assure the project will function as desired at all flows.  In addition, potential impact to the upstream floodplain as a result of project improvements is considered. To the extent practical, woody debris in incorporated into the design to provide for bank stability, in-stream diversity, and fish and wildlife habitat.