Lake, Cook counties to remove 3 dams along Des Plaines River
Water quality and wildlife habitat along portions of the Des Plaines River are expected to improve with the removal this fall of three dams in Lake and Cook counties.
Officials in both jurisdictions continue to go with the flow of a program that began several years ago but that has slowed in part because of issues with state funding.
Tired of waiting for an approved grant they may never receive, Lake County leaders have budgeted $690,000 to remove the last two dams on their stretch of the river. Thought to have been built in the 1930s for agricultural use, the low-head concrete dams are at the MacArthur Woods and Captain Daniel Wright Woods forest preserves near Libertyville and Mettawa, respectively.
"Everything is in place and now is an excellent time to be working in the Des Plaines River because there's no water," said Jim Anderson, director of natural resources for the Lake County Forest Preserve District.
And in mid-August, Cook County will be taking out the Dempster Avenue Dam in Des Plaines. When complete by the end of October, three dams will remain in the county's portion of the Des Plaines River, according to Eric Otto, an engineer with the Forest Preserve District of Cook County.
"We're anticipating removing them whenever funding comes from the state," he said. "The projects aren't on hold; we're moving ahead with the permitting and design."
Both counties have been working with the Illinois Department of Natural Resources and the U.S. Army Corps of Engineers on dam removal along the Des Plaines and the North Branch of the Chicago River.
The dams were built for recreation, sanitary waste purposes, or as farm equipment crossings. But they have become obsolete because of regional wastewater treatment facilities and highway bridges, and they prevent the movement of fish, trap silt and pose potential hazards to paddlers.
"Our senior wildlife biologist is always excited by the fish species he sees after the dams are removed," Otto said.
Anderson said removing the obstacles allows fish, mussels and invertebrates to move. Small mouth bass, for example, have migrated upstream several miles north as a result of efforts to date.
"It's good to get a variety of biodiversity," he said.
Lake County removed the dam at Ryerson Woods in winter 2011. Now, more than a year after a contract was awarded, the last two dams on the Des Plaines River in Lake County will be removed. However, the cost will be paid locally as a state grant was withdrawn.
A final detail to allow the removal of the MacArthur and Wright dams, which are north and south of Route 60 respectively, is expected to be approved Tuesday.
The Lake County Forest Preserve Board will vote on a recommendation from its finance and administrative committee to increase the contract with Michels Corp. of Park Ridge by $25,146 to $519,580. The increase is needed for Michels to buy additional insurance as required by Hollister Inc., co-owner of the MacArthur Woods dam.
Those old dams were used to access farmland on either side of the river.
District officials earlier this year included $690,000 in the 2016/17 capital improvement plan to cover the costs of removing the two dams. The district had secured a $750,000 grant from the Illinois Department of Natural Resources and was to have been reimbursed for all costs, according to Anderson.
The district last summer was told the funds no longer would be available. Whether they ever will be is unknown, he said, so officials decided not to wait because of the importance of the project.
"There is a possibility the funding comes back and we could get reimbursed, but the forest preserve isn't counting on that," Anderson said.
The exact age of the concrete dams is unknown, but they appear on aerial maps in the 1930s.
The Wright Woods dam is 140 feet across and the Macarthur Woods dam is 94 feet wide, Anderson said. Both are about 2 feet tall and front 25-foot wide concrete aprons that span the river.
Anderson said the district is collaborating with IDNR and the Illinois Environmental Protection Agency to sample above and below the dams before and after removal for an expected three- to five-year period.