News

DuPage River Dam Diminished for Nature

The Forest Preserve District of DuPage County has begun the modification of a three-foot-high dam at McDowell Grove Forest Preserve in Naperville to revert a portion of the West Branch of the DuPage River from a lake back to a free-flowing stream.

"For years and years, people built dams and turned their backs on the rivers. Only now are we realizing the damage they've caused to aquatic organisms and river processes," explains Leslie Berns, manager of natural resources for the district. "A key component to reversing this damage is the removal of dams."

While not removing the dam entirely, this project will allow water to flow freely, thus eliminating oxygen-deficient, stagnant water that has proven inhospitable for fish populations. Phases of the project include restructuring the dam, channel restoration, sediment removal, and habitat restoration along the riverbank. The preserve will be closed to motor vehicle traffic until the project's slated completion date of mid-October.

The dam's abutments are part of an old Civilian Conservation Corps (CCC) structure built during the Great Depression as part of a Public Works program. As such, the abutments will remain during the restructuring. "Our goal is to let the river be a river, creating improved habitat and good hydraulics while maintaining its historical structure," says Berns.

In other DuPage River news, a new stream research center is scheduled for construction along the river at Blackwell Forest Preserve. This small facility will get universities involved with the research of urban streams, habitat restoration, and the reintroduction of aquatic species such as endangered and threatened mussels. Plans for the facility also include possible educational components and activities for the public.

— Jennifer Tang