In July of 2017, high flood waters generated by a large storm resulted in the closing of Countryside Drive at the Bull Creek Tributary in Libertyville Township. The flooding had damaged all four of the 58-inch-diameter corrugated metal pipes, causing the paved road to collapse.
The Township needed a quick and effective solution and called on Gewalt Hamilton Associates (GHA) to undertake the repair. GHA conducted a hydraulic analysis of multiple replacement and repair options, including box culverts, RCP culverts, an arch span, and lining the existing culverts. Due to the urgent need for a replacement, coordination with local manufacturers was critical to determining the option most ready to install. GHA’s familiarity with local and federal regulatory agencies made expediting emergency permits possible, and construction began in August.
GHA services included preparation of engineering plan documents, specifications, and bidding documents necessary for the replacement of the culverts. The engineering plan set included plans for existing conditions and demolition, proposed grading, geometric layout and utilities, storm water pollution prevention, a suggested construction phasing plan, general notes and details. A detailed hydraulic analysis was provided of both existing and proposed conditions for the Bull Creek Tributary floodway floodplain, demonstrating compliance with floodplain regulations. GHA also coordinated the wetland delineation review, jurisdictional determination, and Regional Permit authorization with the Lake County Stormwater Management Commission, US Army Corps of Engineers, Illinois Environmental Protection Agency, Illinois Department of Natural Resources, and U.S. Fish & Wildlife Service.
Within the Township’s accelerated timeline, the failed culverts were replaced with a double-reinforced concrete box culvert in September 2017, providing a stabilized stream crossing prior to additional storm events in October 2017.