The costs of a regional approach to address flooding along two river forks that run through Highland Park, Lake Forest and Deerfield outweigh the potential benefits, according to the U.S. Army Corps of Engineers.
The recent conclusion comes after Highland Park officials last year asked the federal agency to initiate a preliminary study and assess whether a regional solution could address severe flooding along the Skokie and Middle Fork rivers that has followed major rainstorms, included one in July 2017.
The study, which marked the first step in what could have been a decade-long process, received support from the Lake County Stormwater Management Commission, the East Skokie Drainage District and the city of Lake Forest, among others.
But after evaluating two potential reservoir sites — including one on the former Highland Park Country Club golf course property — the Army Corps concluded the sites would not provide enough flood relief to warrant further consideration and determined a regional approach did not pass a cost-benefit test.
The agency’s final report, which should be released in the coming months, still could help officials pursue flood mitigation grants and possibly find more cost-effective alternatives that could reduce flooding in the area, Highland Park officials said recently.
“We are disappointed with the results of the preliminary study and will continue to push for a solution that will bring much-needed flood mitigation to residents living along the rivers,” Highland Park Mayor Nancy Rotering said in a statement.
The Army Corps of Engineers is responsible for waterway-related capital projects. The federal agency found the Highland Park site adjacent to the Skokie River could hold 130 acre-feet of stormwater.
In stormwater management, an acre-foot is the volume of water held in one acre of surface area to a depth of one foot. A single acre-foot holds 325,851 gallons.
In addition, the Corps looked at a larger storage basin at Half Day Road Prairie near the Middle Fork River. The site, the agency found, could hold 250 acre-feet of stormwater. Both rivers are forks of the North Branch of the Chicago River.
The study included an hydraulic modeling and economic analysis for the watershed that begins in the vicinity of Waukegan and Park City and extends south into Cook County.
“The Army Corps has a cost-benefit ratio for major projects and if a project doesn’t meet certain criteria, the next phase — the feasibility study phase — does not go through,” said Ramesh Kanapareddy, director of public works for Highland Park.