Master naturalists consider pros and cons of dam removal in Grand Rapids

Grand Rapids is one of many communities in Michigan where aging dams offer opportunities for habitat enhancement. An upcoming program will focus on what this might mean for fish populations.

Over 2,500 dams block the natural flow of Michigan’s rivers. In many cases, these dams no longer serve their original purpose. In Grand Rapids, a series of four small cofferdams were initially intended to beautify the Grand River and prevent the foul odors that arose from polluted waters when parts of the river channel ran dry. That was nearly a century ago, and improvements to water quality paved the way for current discussions regarding the future of the river.

While the small cofferdams serve little purpose, a larger structure known as Sixth Street or Fourth Street Dam is now providing unintended benefits in the form of invasive Dam in low water in Grand Rapids, Michiganspecies control. This dam is the first barrier to sea lamprey migrating upstream from Lake Michigan, and its removal would open 1,500 miles of river and stream habitat to this parasitic pest.

Multiple groups are now considering options to remove some or all of the dams in a manner that would provide for lamprey control while enhancing economic benefits from recreational activities such as whitewater kayaking and fishing. Development of parks and private properties along the river could greatly benefit the city following dam removal, while impacts from floodwaters and invasive species could be severe if not accounted for in the planning process.

For those motivated by a desire to restore natural riverine habitat, the situation in Grand Rapids raises difficult questions. Full restoration of historic rapids and floodplains will not be possible because floodwalls now protect the city and the bedrock if the rapids were removed in some areas. Even plans for partial restoration of the rapids will include a sea lamprey barrier that will also block many native fish from moving upstream. Even so, there is some opportunity to enhance existing habitat for native species and improve fish passage. 

On Saturday, August 24, Michigan State University Extension is offering a program at the Kent County office for those interested in learning more about fish species found in the Grand River and how dam removal might affect them. The program is geared toward graduates of the Master Naturalist program and also qualifies for Master Gardener recertification (4 education hours). Full details can be found on this flyer. The cost is $30.00, non-refundable. Space is limited and registration is required.