Posted on April 20, 2023
As part of its ongoing effort to address the sand and sediment buildup in the Kankakee River, the Kankakee County Board approved a hydrographic/bathymetric survey of waterways in the county.
On the recommendation of the Planning, Zoning and Agriculture Committee, the board unanimously approved at its regular meeting on Tuesday the selection of Prairie Engineers to do the survey at a cost not to exceed $196,000.
A hydrographic survey studies bodies of water to see what the floor looks like — how much mud or silt is on the bottom. A bathymetric survey measures the depth of the waterway, as well as a map of underwater features.
“This is a big deal,” Kankakee County Board Chairman Andy Wheeler said.
Prairie Engineers, of Columbia, Ill., will survey both the Iroquois and Kankakee rivers in Kankakee County as well as the Singleton Ditch, which flows into the Kankakee River.
“They will be surveying the entirety of both rivers, about a quarter mile into our surrounding counties because we don’t want to stop right on the county line,” said Delbert Skimmerhorn, director of planning and GIS for Kankakee County, noting that the Singleton Ditch will be added to the survey of the two rivers.
“Singleton is important to us,” Wheeler said. “It’s a major sediment load and drainage load into the river.”
Prairie Engineers is expected to start the surveying within a week. The company will use enclosed cabin boats, open hold boats and remote control boats to do the surveying. It will use GPS positioning and inertial monitoring as well as sonar to get accurate measurements.
Scott Perkins, quality manager with Prairie Engineers, said the equipment used “gives us the ability to assess the depth of consolidated material and the bottom of the river, or what you and I might call mud.”
Perkins, who will manage the project for Prairie Engineers, gave a slide presentation at the county board meeting.
“At the end of the day, we’re going to be able to estimate the volume of mud sitting on top of the bottom of the river that potentially could be removed through dredging,” he said.
Perkins said the survey work on the two rivers and Singleton Ditch will take 12 weeks to complete.
The survey by Prairie Engineers is just one component of the county’s effort to stem the tide of the decades-long buildup of sediment in the Kankakee River. This past year, State Sen. Patrick Joyce, D-Essex, secured $1 million from the state to dredge a portion of the Kankakee River in Aroma Park at the boat launch in Potawatomi Park and also near Ryan’s Pier.
The dredging work likely won’t begin until next year while a freshwater mussel survey is completed on the Kankakee River at the site. Burke Engineering, of Indianapolis, Ind., will be doing the mussel survey as well as overseeing the dredging project.
County board member Craig Long said he participated in the original GIS mapping of Kankakee County, and there are unknowns with the river.
“We know what the face of the county looks like because of the GIS,” Long said. “We do not know what the bottom of the Kankakee River looks like. Kankakee River is one of our most important assets, besides the agricultural ability of this county, for recreation and for providing water to many, many communities.
“… There’s a lot of things that we’ll figure out in the future that will be beneficial for, but right away that the mapping is going to help us in the projects we’ve already had started in Aroma Park.”
WHAT INDIANA IS DOING
Indiana is also addressing the flow of sediment from its side of the state line into the Kankakee River.
Scott Pelath, executive director of the Kankakee River Basin and Yellow River Basin Development Commission, spoke this past fall on what his Indiana-based commission is doing to try to alleviate the flow of silt in the future.
The Indiana legislature finally decided to do something substantive and aggressive about the Kankakee River in Indiana,” said Pelath in September. “We now have a 40-year work plan developed by our friends here from Burke Engineering that was adopted under state statute. And we also have about $3 million a year that’s allocated for decades to come to address our piece of this problem upstream of the state line.”
Pelath said Indiana is aggressively addressing the problem by reconstructing a mile and a half of the Yellow River stream bank that’s emitting sediment that ends up in the Kankakee River.
Wheeler said the county has some data on the river dating back to the 1950s and ‘60s, and this survey work will help compile what has changed in the river over the years.
“As we start to address sedimentation, rebuilding shoreline and things like that, this is essential data to see if what we’re doing is working or if we’re targeting the right areas,” Wheeler said.
“This could not be coming at a better time of providing that. We’re gonna be working on this for 30 to 40 years on the river, so this is the foundational. … Basically, it’s our basis. It’s what are you looking at in greater detail than we’ve ever seen? And then we’ll be able to watch it evolve.”