For anyone who believed that somehow the removal of the Fairbank and Hofmann dams on the Des Plaines River in Riverside were a flood-prevention operation, the mid-April rains that caused the river to crest at a record level proved otherwise.
The flooding damaged homes throughout the Chicago area, inundating basements, destroying possessions. In Brookfield, it drove at least one couple on Forest Avenue to leave town — they had lost almost everything.
In Riverside, the flooding also affected the river itself and strongly tested improvements made last fall to Swan Pond Park. As the flood waters receded, the power of the flood became evident.
The river overflowed the stone retaining wall on the Riverside bank of Swan Pond Park at a low point near the former location of the Fairbank Dam. The current was so strong that, in several places, it washed out the gravel base of the asphalt walking path, which simply collapsed.
A large tree trunk, which had traveled from upstream, wedged itself at the base of an oak tree and the wall. Its presence served as something of a dam itself, and the rushing water scoured the earth at the base of the oak, as if a team of workers had excavated it.
“In that area, where the water met the wall, the water was so strong it was turning like a tumbler,” said Village Manager Peter Scalera.
The path will be rebuilt, according to Scalera, but exactly whose responsibility it will be to pay for the repairs is unclear at this time. The Army Corps of Engineers, which was responsible for the improvements, was in the village last week to inspect the damage. Indications are that if the damage is determined to be the result of a “natural disaster,” the repair will fall to the village. If the work was somehow faulty, the Army Corps will be on the hook.
“I don’t believe the path should have collapsed to the extent it did,” said Scalera. “The water took stone from underneath and put it on the other side of the path.”
The flood was a test of the new drainage system for Swan Pond Park, created in large part by regrading the flood plain so that the water flowed toward a culvert and back out into the river as the water level fell. The floodplain had drained almost completely by May 3.
“I think that’s working,” said former village trustee Lonnie Sacchi, who was instrumental in advocating for the village during the dam removal and Swan Pond improvement projects, “but a lot of silt and sand got dumped in the park.”
Most of that silt and sand, along with countless zebra mussel shells could be seen in the area where the water first overtopped the bank. But the large mud flat left in the middle of the park where the water collected before draining from the area remains a concern.
That area was planted last fall. It’s unclear whether the seed will still sprout or was simply washed away. The park has been flooded on two occasions this spring.
“We haven’t had a good stretch for the seed material to take hold,” said Scalera. “More than likely we’ll have to reseed that area.”
While the village may explore alternatives for the walking path, there’s not much it can do about future flooding. Swan Pond Park is a flood plain, and it’s going to remain a flood plain.
The river itself, at least above the former Hofmann Dam site, looks a bit different now than it did a month ago. While the large boulders placed on the banks to stabilize sediment remained firmly in place, smaller river rock from upstream deposited itself in the area where the river narrows sharply, slightly downstream from where a rock shelf already exists.
“That natural rock shelf was a feature that we figured during flood events would change its look,” said Jeff Zuercher, project manager for the Army Corps of Engineers. That’s one feature that will change its appearance over time.”
Still scheduled for later this month are new plantings — of shrubs, water willow and other plants — along both banks of the river upstream of the former dam sites.
