The Busse Dam modification project will help alleviate flooding in both Cook and DuPage Counties. Elk Grove Village as well as the many communities downstream along Salt Creek will benefit from the reduction in flooding. The project may benefit upwards of one million people who are currently affected when flooding damages property and closes critical intersections. The disruptions during a flood event can cost our region millions in lost commerce and social impacts, such as school closures, church closures and residents unable to access their homes.
“This project is the culmination of nearly eight years of multi-agency collaboration, engineering studies, modeling, and design work.” said Mayor Craig B. Johnson, “We are excited to be on the cusp of bringing the flood relief sought by Elk Grove Village and communities in the Salt Creek Watershed since the Dam’s original construction in the 1970s.”
The Busse Woods Reservoir was constructed in 1975 as a joint project of the Illinois Department of Natural Resources (IDNR), the Forest Preserve District of Cook County (FPDCC) and the Natural Resources Conservation Service (NRCS) to provide flood mitigation downstream along Salt Creek in Elk Grove Village.
The construction of the Dam created what is now called Busse Lake. The lake serves as a significant recreational amenity of the Forest Preserve District for boating and fishing.
Busse Woods itself contains several sensitive ecological systems that will benefit from the Dam modification. Following floods in 2008, which significantly impacted Elk Grove Village, the Village revived interest in making the reservoir function better for flood relief purposes while also improving the ecology of the Forest Preserve. At that time, the Village worked closely with the Friends of the Forest Preserves who creatively designed the Dam modification proposal that is nearing construction.
Moreover, the Village worked closely with many governmental entities. Mayor Johnson noted that:
“This project could not have come to fruition without the assistance of many people. We especially want to thank “Cook County Board President, Toni Preckwinkle, DuPage County Board Chairman, Dan Cronin, General Superintendent of Forest Preserves of Cook County, Arnold Randall, and MWRD of Greater Chicago Executive Director, David St. Pierre, along with many neighboring Mayors and the staff of many Federal, State, and local governmental agencies. Everyone worked together as a team. We all understood the regional benefits of reducing flooding through this project and the ecological improvements associated with the project as well.”
The Busse Dam modification project consists of two hinged gates, which allow for control of the outflow of the reservoir. During normal operating conditions, the top of the proposed gates will sit at the current fixed weir elevation. During a storm event, as the water surface elevation of Busse Reservoir increases, the gates would be slightly lowered to ensure that the inflow into the reservoir is equal to the outflow, allowing the normal water level of the reservoir to remain constant. As the water surface elevation of Salt Creek downstream rises and maximizes flow within the creek without overbank flooding, the gates would then rise to store floodwater within Busse Lake. As the storm event subsides, or the reservoir reaches a critical elevation as determined by ecological studies, the gates would be lowered back down to the normal operating elevation, allowing the gates to dynamically adjust to each unique rainfall event and maximize storage within the reservoir.
Elk Grove Village engineers modeled 158 historic rain storm events over the past 7 decades, in which 37 events caused severe, damaging flooding. If the gates had been operational, only 17 events would have resulted in minor flooding downstream, and only a few in damaging flooding. Benefits for the threatened and endangered species within Busse Woods Forest Preserve are even greater: In all 37 flood events, the gates would have reduced both the severity (depth) of the flooding and the duration of flooding by cutting the flood inundation hours above critical elevations within the preserve in half.
Additional modeling has been performed to optimize the Busse Woods Dam Modification in coordination with downstream flood control structures in DuPage County. Model results will provide DuPage County with additional flexibility on how/when to operate their flood control structures and provide an even greater level of flood protection to residents of DuPage County along Salt Creek.
Elk Grove Village