MSU Seeks Weir Removal to Improve River Health

Michigan is actively removing aging dams and weirs, structures used to control water flow across rivers and streams, as they near the end of their useful lives. The Michigan Department of Natural Resources (DNR) prioritizes funding for dam removals over repairs or replacements, with $350,000 of its $1.8 million fisheries habitat grants allocated specifically for this purpose.

Dams and weirs disrupt fish migration, blocking species’ ability to travel upstream or between wetlands and lakes to lay eggs, which affects their reproduction. While some fish can jump over small barriers, many species are negatively impacted by these obstructions. Additionally, the upstream environments behind dams can accumulate sediment and silt, creating unhealthy habitats for aquatic life, including fish, invertebrates, and native clams.

Jo Latimore from MSU’s Department of Fisheries and Wildlife explained that the water upstream of a dam slows, causing sediment to settle and muddy the riverbed. The muddy conditions create an unhealthy ecosystem for aquatic animals that prefer a substrate of gravel and rock.  Dam removal not only improves habitats but also reduces flooding risks, as dams often cause water to back up during high flows.

MSU is seeking a DNR grant to remove a weir on campus that was originally built in 1878. While the weir no longer serves its original purpose, it continues to negatively impact the river’s ecosystem and increase flood risks. The DNR supports the removal of these structures, considering both ecological benefits and safety concerns, especially as climate change brings more frequent heavy rainstorms that stress aging infrastructure.

Read the full article on The State News.