Little Menomonee River

The Department, through its Ecological Division – Fish Passage Program, is implementing an aquatic connectivity and large-scale habitat restoration and enhancement project on a publicly owned parcel on the Little Menomonee River in the City of Mequon. Approximately 3.77 miles of mainstem channel on the Little Menomonee River and Little Menomonee Creek between County Line Road and Freistadt Road had historically been altered through construction of road and stream crossings and dredging and artificial straightening of historic wetlands and stream corridors resulting in an incised channel hydrologically disconnected from adjacent riparian floodplain and wetland areas, which provide high quality habitat for spawning northern pike and other aquatic and terrestrial species.

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The primary goal of this project has been to develop engineering and design plans for permitting and to conduct construction and restoration activities (with aquatic organism passage projects as a priority) at a parcel previously owned by MMSD on the Little Menomonee River to holistically improve aquatic connectivity in the watershed and enhance the channel, riparian corridor, and floodplain system within the project area. The property was acquired from the Milwaukee Metropolitan Sewerage District in 2021 and added to the Ozaukee County Park System. This site was originally identified by the County as high priority for restoration and preservation.

The Department received funding in 2017, from the Fund for Lake Michigan, and in 2019, from the Wisconsin Coastal Management Program, to support engineering and design to holistically improve aquatic connectivity in the watershed.

Ongoing restoration work by Ozaukee County started in 2019 and these activities have improved the function of the Little Menomonee River 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. The new stream channel provides high quality, diverse in-stream, wetland, wet prairie, and forest habitat for fish, birds, reptiles, amphibians, and mammals, improves water quality, and reduces flooding and erosion risk. In March 2021, the Ozaukee County Highway Department completed the remeandering of the remaining portion of the new stream channel (approximately 400 linear feet), installed woody debris for in-stream habitat, installed the fish passage culvert within the new stream channel with seeding of disturbed areas (and removed the old collapsing culvert), and reconnected the emergent marsh wetland to the Little Menomonee River (new channel).

In addition to the stream restoration, an ephemeral wooded pool has been created to provide habitat for amphibians and reptiles, an emergent marsh has been created to provide habitat for fish, and a deeper wetland with open water and marsh has been created to attract and provide habitat for migratory waterfowl and shorebirds. Forested wetland and wet prairie habitats are being restored around the wetlands and provide additional bird, pollinator, and other wildlife habitat.

Remaining project elements include water quality monitoring, fisheries monitoring, and ongoing restoration and restoration maintenance of all disturbed areas (e.g., additional tree planting, native prairie/wetland seeding, or invasive species management).

Initial Property Restoration Plan

LMR Plans

Overhead View of the Property After Restoration