Fish Passage

Throughout 2011 and 2012, Milwaukee Riverkeeper identified fish passage impediments and opportunities for aquatic habitat restoration in the 136 square mile Menomonee River Watershed (excluding concrete channelized creeks and upstream of the Lepper Dam in Menomonee Falls).

The Menomonee River Watershed flows 28 miles before joining the Milwaukee River just prior to its confluence with Lake Michigan. While the Menomonee River fishery is characterized as poor, fish species numbers have increased in recent years due largely to the removal of the Falk Dam and greater colonization by Lake Michigan fishes migrating up the Menomonee from downstream.

Urban development in the watershed has created many impassable culverts, has filled in/altered habitat, and has created other artificial barriers like small dams and drop structures. These barriers then serve to fragment important habitats and impede fish and other aquatic life from accessing existing higher quality habitats upstream. In addition, stream impediments also affect recreation, decreasing fishing opportunities and creating hazards for paddlers.

Milwaukee Riverkeeper identified partial and complete stream impediments along the natural mainstem reaches of the Menomonee and Little Menomonee Rivers, as well as 10 major tributaries that are not concrete channelized or enclosed, and that provide access to higher quality natural areas that could be used for fish spawning or rearing. Removing obstructions to fish passage and restoring access to high quality natural areas is the most cost effective way to increase aquatic life diversity and productivity in the Menomonee River Watershed.

Over 382 potential barriers were identified and assessed, with 126 of those found to be significant. In addition, 75 areas of potential spawning habitat for northern pike and other native fish were identified. Suspected barriers fell into several categories including: passable minor debris jams; major debris jams; human caused barriers such as perched culverts, weirs, fords, or degraded pipe crossings; and natural barriers such as the namesake waterfalls in Menomonee Falls, areas of sediment deposition, etc.

Fish Passage Impediment Project

As part of this project, 14 volunteers were trained on how to identify, document, and measure fish passage impediments as well as identify areas of potential aquatic habitat associated with our waterways.

Milwaukee Riverkeeper has already had some success working with impediment owners to address priority fish passage impediments downstream. Milwaukee Riverkeeper paid for some conceptual designs to be developed to address five low-flow barriers in the lower Menomonee River, and MMSD is building on this work and has procured funding to address these barriers in 2014.

Milwaukee Riverkeeper is also working with municipalities and counties to help devise plans to address these significant fish passage barriers over time. We hope to help fundraise to remove fish passage impediments, to clear out woody debris barriers with volunteers and paid work crews, and to help advocate that government agencies use their capital funds to improve fish passage and habitat.

There are excellent opportunities to address many natural and human caused barriers to fish passage and connect native fishes like northern pike with suitable areas of upstream habitat for spawning. The success of this work will depend on continued collaboration among our watershed partners in the future.

Below are attachments of our final report for our fish passage survey to our funders (Wisconsin Coastal Management Program and WDNR), as well as the maps that we have created with the location of impediments and potential aquatic habitat restoration opportunities. We have also attached reports on these impediments (and some potential habitat areas), which displays available data and photos downloaded from our field computer. Please contact Joe or Cheryl with any questions!


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*The great people over at Ozaukee County are also working on the issue of fish impediments and they have an underwater camera, which catches the critters that pass through their Mequon-Thienville Fish Passage.

Check out the live stream (pun intended)!

Attachments

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