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The County of DuPage
Wheaton, Illinois

Warrenville Grove Dam Modification

The Warrenville Grove Dam Modification project is a priority within the DuPage County West Branch DuPage River Watershed. Modification/removal of the Warrenville Grove Dam is a key component in improving the water resources of the West Branch DuPage River watershed.

he purpose of this project is to restore the ecological health of an impounded segment of the West Branch DuPage River extending the length of Warrenville Grove Forest Preserve. Through the notched removal and modification of the existing dam and re-creation of upstream and downstream channel conditions, this project seeks to:

  • Restore the natural ecological functions and processes of a free- flowing river segment
  • Decrease lake-like conditions upstream of the dam that support high algal biomass, high water temperatures, and substandard dissolved oxygen levels, considered a non-pollutant impairment by Illinois Environmental Protection Agency (IEPA)
  • Decrease barriers to fish movement and mussel dispersion
  • Decrease liability exposure and maintenance of the dam
  • Provide improved educational and recreational opportunities for the community
Warrenville Mill Race Concept Plan
Warrenville Mill Race Concept 
Rendering of River Post Dam Modification
Rendering of River Post Dam Modification 
Existing Warrenville Grove Dam
 Existing Warrenville Grove Dam 
Mill Race at Warrenville Grove Dam
Mill Race at Warrenville Grove Dam 

Letter of Support for Dam Modification from Governor Quinn (then Lieutenant Governor) (PDF)