Work crews in Lake in the Hills are expected to finally begin dredging Goose Lake next month and if the job is long-awaited by homeowners and environmentalists, it also is going to be a much larger job than anyone expected.
“The amount of silt in the lake is approximately triple (previous estimates),” said public works director Ralph Ridley.
The village originally budgeted $75,000 to dredge Goose Lake, based on estimates. But Gail Miller, the ecological consultant hired by the village to lead its lake restoration efforts, said she expects the cost likely will be two to three times higher.
Miller said earlier estimates by Wight Engineering in 1993 “were really just guestimates. Until you do the thorough survey, you can’t know for sure how much sedimentation there is.”
News that the job will be bigger than expected came as the village was preparing to obtain the necessary permits from the Army Corps of Engineers and hire a company to do the work.
The dredging, which also will be done to two other lakes, has become necessary because of the area’s construction boom. Soil from developments under construction run off into feeder streams, such as Crystal Creek, and into the lakes.
In addition, an increase in the amount and velocity of water discharged from two nearby sanitary stations appears to be eroding the shorelines and carrying off even more soil.
The Wight report indicated the average sediment depth on the approximately 10-acre lake bordered by homes on Hiawatha Drive and Council Trail was a half-foot to 1 1/2-feet deep.
G. Miller Consulting engineers did a more detailed survey and found the average sediment depth ranged from two to four feet. Preliminary calculations show that 42,000 cubic yards of sediment are present in the lake, up from the 13,000 cubic yards predicated by Wight engineers.
The village has applied for two state grants to cover some of the dredging expenses and help pay for shoreline reconstruction and storm-water management on the lakes.
In the meantime, engineers are searching for alternative sediment removal methods that might be more cost-effective.
Dredging also is planned for Willow Lake and Scott Lake.
Once the silt is removed, engineers will begin to restore the lakes’ ecological state so plants and aquatic life can thrive again. The lake bottoms will be redesigned, creating “shelves” of varying depths that will support a wider variety of plants and fish, Miller said.
Presently, Goose Lake has no plant life and bears only carp, a bottom-feeding fish that thrives on bacteria. And since there are no plants and other animals to feed off the overwhelming amount of bacteria, the lake emits a gas odor, Miller said.
“It’s all a matter of time,” Miller said. “As more and more soil and fecal matter collect, it just sits there and boils in the warm water. It only gets worse. There’s so much bacteria eating itself, it emits a gas. The water smells worse than last year. The carp have sores on them. I hate putting my hands in the water just to take samples.”
