Bee Slough River Floodgates

The City of Evansville is implementing the Integrated Overflow Control Plan (IOCP), the largest public works project in the city’s history, to address water quality in the Ohio River. Central to this effort is the restoration of Bee Slough, a major concrete-lined swale that directs roughly 70% of the city’s combined sewer overflow (CSO) volume toward the river.

Bee Slough is now equipped with a new floodgate structure featuring two 10-foot by 9-foot flap gates at its downstream end, allowing surface drainage to flow freely while preventing backflow from the Ohio River. CHA’s design of this structure enables the Evansville Water & Sewer Utility (EWSU) to better pump out and drain water in the slough, reducing stagnant water and associated odors. Hydraulic controls were fit within a tight space.

This design increases CSO containment and treatment, marking a vital step toward healthier waterways and improving the quality of life for residents in the historic neighborhoods of Evansville. Additionally, ADA-compliant ramps and sidewalks were added to make the structure accessible to everyone. This integration of community-friendly features into wastewater infrastructure is unique and has already garnered positive public perception.