Along the Des Plaines River from Riverside to River Forest, changes are afoot. Conservation efforts are brewing that could have impact up and down the river.
The Illinois Department of Natural Resources (IDNR) and the U.S. Army Corps of Engineers are planning to notch-remove the middle 150 feet-of the 258-foot Hofmann Dam, which is located between Riverside and Lyons at Barrypoint Road. They also plan to remove two dams upriver, the Fairbanks and Armitage Dams. At the same time, the Hofmann Dam River Rats, the IDNR, and the Des Plaines River Valley Volunteers are cleaning the river and the surrounding woodlands.
Because it is so close to Chicago, the Des Plaines has historically had poor water quality, Tim McCloud, IDNR communications manager, said in an e-mail message. But that has changed over the last 30 years with passage of the 1977 Clean Water Act. That federal action required treatment of wastewater. In that time, fish populations have made a comeback, especially just downstream of the Hofmann Dam, McCloud wrote. According to the summer 1998 issue of Chicago Wilderness magazine, volunteers collected just 1,008 fish and 32 species in 1983. In 1997, however, volunteers collected 3,374 fish and 40 species.
During this period of abundance in the mid-1990s, the Hofmann Dam River Rats were founded by a Chicago police officer, Jason Gorski. The River Rats are a group of fishermen who cast their lines in the bountiful area around the dam. At the same time they were beginning to lobby for more attention to the Des Plaines, the IDNR was accelerating its efforts to make the river healthier.
From 1995 to 1997, the IDNR stocked 50,000 4-inch smallmouth bass in the stretch of river downstream of the dam. Then, in 2001, with help from the River Rats, the IDNR began releasing 6,000-12,000 2-inch sauger fingerlings into the lower Des Plaines every year. The last cohort was introduced at Riverside on June 6 of this year.
To protect the game fish in the popular lower Des Plaines the IDNR, with the cooperation of the River Rats, instituted fishing regulations that limit the daily catch for all the major sport species.
The area downstream of the Hofmann Dam was thriving, but the River Rats wanted to be able to fish successfully on even more of the river, so they began pushing for the removal of dam.
The Army Corps of Engineers, after meeting with stakeholders, decided to change the Hofmann Dam, as the River Rats wanted, but not to completely remove it. Instead, they decided to notch the dam, which would be less expensive than total removal.
The purpose of the proposed project is to increase the species diversity upriver of the dam, an area that extends through Forest Park and River Forest up to Wisconsin. The changes to Hofmann Dam and the removal of the two dams upriver would open up a 20-mile stretch of the river to recreation, from Hofmann Dam to Devon Avenue. The dams would be the among the first in Illinois to be removed or notched for environmental reasons, after the Rooster Creek Dam, located on a tributary of the Fox River in Kane County.
The Army Corps of Engineers currently has approval to make detailed plans and specifications for changes to the dam, but is waiting for federal and state funding. According to civil engineer Mike Nguyen, the project manager for the dams at the Army Corps, 65 percent of the funding will come from the federal government, and the other 35 percent will come from the IDNR. The project will cost an estimated $2 to $3 million, said Frank Veraldi, a fish biologist at the Army Corps who is the plan formulator for the dam project.
Veraldi said that the proposed notching would allow about 20 species of fish to recolonize upriver of the Hofmann Dam, including silver redhorse, skipjack herrings, and freckled madton.
The changes would also have some effect on water levels around the dam. According to Riverside Director of Public Works Michael Hullihan, the changes would “not be a great flood capacity improvement, but might help a little bit” with diminishing flooding upriver of the dam.
There is some concern that flooding would increase downstream-generally, south-of the dam. But Hullihan said that the “water level wouldn’t be affected outside of a very short level up and downstream because there’s enough storage behind the dam.” Veraldi agreed: the dams provide “no flood control benefits or impact with flooding,” he said.
Hofmann Dam River Rats President John Mach was one of the founding members of the Hofmann Dam River Rats in the mid-1990s, later replaced Gorski as president, and helped come up with the idea to notch the dam. He is optimistic about the proposed changes to the river.
Mach downplayed concerns about removing the dam. “Hofmann Dam does nothing,” he said. “It has no flood control capability. It has no electric power.” The real flooding problems, he said, come from run-off from storm sewers that are released into the river.
While the dam plans are in funding limbo, the Des Plaines River Valley Volunteers, the River Rats, and the IDNR are working to keep the river and surrounding forest preserves as healthy as possible.
Oak Parker Barbara Birmingham works with the Des Plaines River Valley Volunteers to remove buckthorn and honeysuckle from the forests around the river. Removing those plants “brings in light…encourages the plants that should be there to grow, and makes for a healthier watershed,” she said.
The River Rats, for their part, plant water willows with the support of the IDNR along the banks of the river up- and downstream of the Hofmann Dam. They also helped design rock habitat structures with the IDNR in the channel section of the river near Hodgkins.
In addition, Mach’s group does water-quality tests on the river by counting for species of bugs that have different tolerances for pollutants. “What we think we’re seeing is that the quality went up to a certain level, and now it’s starting to level off,” Mach said. “Without some major alteration, that quality will not continue to improve.”