Project restores nearly 600 acres and adds capacity to store 110 million more gallons of stormwater annually
September 23, 2025 – After nearly two decades of dedicated restoration, the O’Hare Modernization Wetlands Mitigation Project at the Forest Preserves of Cook County’s Deer Grove in Palatine is officially complete. What began as a mitigation response for wetland losses due to the expansion of O’Hare International Airport has become a landmark restoration effort that continues in the landscape and communities of Deer Grove.
“The completion of restoration at Deer Grove is a tremendous milestone for the Forest Preserves,” said Cook County Board and Forest Preserves of Cook County President Toni Preckwinkle. “This work not only revitalizes the prairies, woodlands and wetlands that make Deer Grove so special, but it also delivers real benefits for our communities with cleaner water, better flood protection and healthy natural areas that people can enjoy for generations to come.”
The work funded by O’Hare Modernization Wetlands Mitigation funds was conducted by Openlands in partnership with the Forest Preserves of Cook County, with guidance and support from multiple agencies: Stantec, the U.S. Army Corps of Engineers, Audubon Great Lakes, Chicago Department of Aviation and many dedicated volunteers from Deer Grove Natural Areas Volunteers.
Thanks to this project, Deer Grove has been transformed with more than 589 acres restored, including 41 acres of wetlands, and major work in prairies, woodlands and other natural areas. Restoration efforts included hydrologic improvements, such as restoring water flow and fixing drainage issues, invasive species removal, native seeding and planting, the use of prescribed burns, and interpretive signage to engage the public.
“I think one of the most compelling things about the Deer Grove-East project is that it was done without closing the preserve,” says former Openlands restoration ecologist Linda Masters. “The public was able to witness the entire transformation of a place that was overgrown with invasive brush to one with views and a diversity of plants and animals.”
Thanks to deep-rooted prairie plants and revitalized wetlands, Deer Grove-East can absorb 110 million more gallons of stormwater per year than before restoration. ‘’These landscapes improve water quality, reduce flooding, and recharge groundwater, and they give people a place to truly immerse themselves in nature. Even in the third-largest city in the country, people don’t have to travel far to experience diverse and rare natural areas. Our Forest Preserve system is a unique and invaluable asset, and Deer Grove is a shining example of that.’’ says Michael S. Davidson, President and CEO at Openlands.
“The success of the Deer Grove Forest Preserve habitat restoration project demonstrates the importance and power of collaboration for restoration and ecological stewardship,” said David Bart, senior ecologist at Stantec. “It has been our honor to work with Openlands, the Forest Preserves of Cook County, the Deer Grove Natural Area Volunteers, and our project partners for the last 17 years. Between Deer Grove East and Deer Grove West, the 589-acre enhancement serves as a model for restoration in the region. This vibrant transformation provides crucial habitat for native plants and wildlife, and today Deer Grove Forest Preserve is celebrated as a jewel of the local community.”
“For nearly two decades, the U.S. Army Corps of Engineers Regulatory Branch has worked alongside the Forest Preserves of Cook County and our partners to restore Deer Grove’s prairies and wetlands as part of the O’Hare Modernization Mitigation Program,” says Colonel Kenneth Rockwell, a commander with the Chicago District of the U.S. Army Corps of Engineers. “Together with the U.S. Fish and Wildlife Service, the Illinois Nature Preserves Commission, Openlands, and dedicated volunteers, we have transformed more than 180 acres into thriving habitat that people can experience and enjoy. This progress demonstrates how strong partnerships and long-term stewardship can deliver both essential infrastructure and lasting environmental benefits.”
“I am amazed and gratified by the increase in knowledge surrounding this restoration,” says Anne Stake, a volunteer at Deer Grove-East. “Our volunteers are learning how best to support the project through on-going training and hands-on work. And the visitors to Deer Grove that we meet have gone from being very skeptical of the dramatic changes to being very appreciative of the results.”
While the formal restoration and monitoring phases are now complete, Deer Grove will continue to benefit from long-term stewardship and community engagement. Activities such as prescribed burns, invasive species control, habitat monitoring and public education will ensure the wetlands, prairies and woodlands remain resilient.
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Founded in 1963, Openlands protects the natural and open spaces of northeastern Illinois and the surrounding region to ensure cleaner air and water, protect natural habitats and wildlife, and help balance and enrich our lives. Openlands works across areas to advance nature-based solutions to climate change, improve the health and well-being of communities, and create a more verdant region for all. For more information, please visit www.openlands.org
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