O’Hare’s Expansion Forced Chicago To Invest In Wetlands 20 Years Ago. Conservationists Are Seeing Results

PALATINE — The Deer Grove Forest Preserve was teeming with life on a recent Monday morning.

A pair of sandhill cranes pecked at the preserve’s wet earth, hunting for snails, as joggers watched a snapping turtle slowly cross the walking path.

Deer Grove, Cook County’s first forest preserve, wasn’t always this bustling. Conservationists working with the nonprofit Openlands had to spend more than two decades restoring Deer Grove and four other key natural areas as part of the O’Hare Modernization Wetlands Mitigation Project.

The city of Chicago had to make up for the more than 280 acres of wetlands lost in the $8 billion expansion of O’Hare International Airport. In 2005, the city gave the nonprofit Openlands $26 million to restore five sites within the Des Plaines River watershed.

Nearly 20 years and 530 acres of restored wetlands later, Openlands celebrated the completion of the O’Hare Modernization Wetlands Mitigation Project last fall. Now, the sites are still being maintained by local site stewards and volunteers. Samantha Chavez, the director of restoration at Openlands, said the project should be used as a model for similar restoration across the country.

“It was one of the largest restorations in the region’s history and it demonstrated that you can put high-quality habitat back on the landscape at a large scale if you want to,” Chavez said.

‘Cheaper In The Long Term To Invest In Nature’

In the early 2000s, the Chicago Department of Aviation launched the O’Hare Modernization Program, a project that would add more runways and air traffic control towers to the growing airport.

However, the expansion called for development affecting hundreds of acres of wetlands. Under the Federal Clean Water Act, the city would have to compensate for the lost wetlands by restoring other wetlands located in the same watershed.

“This was the last item they needed for the modernization project,” said Joseph Roth, the former director of restoration programs with Openlands. “They were having difficulty getting enough wetland credits and project was at a bit of a standstill.”

The five restoration sites selected for the project were: the Deer Grove Forest Preserve, the Bobolink Meadow Land and Water Reserve, the Hadley Valley Preserve, the Messenger Woods Nature Preserve and the Drummond Floodplain at Midewin National Tallgrass Prairie.

Chavez said most of the sites had been farm fields, which required first removing drain tiles that had been keeping water off the land. Restoration crews then spent years removing invasive species and planting natives.

Anne Stake, a Deer Grove site steward and volunteer who’s been working at the preserve for around 15 years, said it was impressive to see how much the landscape changed once invasive buckthorn and honeysuckle plants were removed and native grasses were planted.

Native plants like Big Bluestem have much deeper root systems than non-natives like Kentucky Bluegrass. These deep roots hold water onsite, allowing it to move through the soil structure, filtering out pollutants like nitrates. Wetlands’ ability to absorb and hold water also reduces flooding because it slows the water’s return to nearby streams or rivers, curbing the likelihood the water table will overflow.

A study done at Deer Grove East found that after the restoration, the landscape absorbed 110 million more gallons of stormwater annually.

This spring, many Chicagoans had to deal with flooded basements as the city experienced record rainfall. Some suburban residents even had to surround their homes with sandbags when the Des Plaines River flooded in April.

Annual precipitation in Illinois has increased by about 5 inches over the past 120 years, according to data from the National Oceanic and Atmospheric Administration. Storms are also getting more severe as the number of 2-inch rain days in the state has increased by 40 percent since the beginning of the 20th century, data shows.

As annual rainfall continues to rise, it’s becoming harder for the city’s aging infrastructure to keep up.

“With climate change, we’re getting more intense rainstorm events and where a lot of the infrastructure before was built for a 20-year-flood, now we’re getting 100-year floods regularly,” Chavez said. “It’s cheaper, in the long term, to invest in nature.”

With recent changes to the Federal Clean Water Act putting 72 percent of Illinois’ remaining wetlands at risk, investing in and protecting these natural resources has never been more important, Chavez said.

A ‘Misunderstood’ Ecosystem

Chavez studied the water lily-lined pond that sits at the center of Deer Grove East.

“A lot of people might see a field that is wet and say, ‘Oh that’s unused space, why don’t we put something there?’” she said. “Actually, that is the most useful thing that could be there.”

Decades of farming and development has left Illinois with just 10 percent of its original wetlands. After a 2023 Supreme Court decision that narrowed the types of wetlands protected under the Clean Water Act, thousands more acres could be lost.

Openlands and other conservation groups are pushing for state-level wetland regulations.

“Federally, wetland regulations tend to be a bit of a hot potato with the regulations changing all the time because of the political climate surrounding what I believe to be the misunderstanding of wetlands and what they do,” Chavez said.

She said “wetlands have historically gotten a little bit of a bad rap. People think of swamps and bogs and mud.”

“Wetlands seem to be the first thing that people want to cover up and get rid of,” Stake, who volunteers with the Deer Grove Nature Area group, said.

Yet wetlands are one of our most valuable ecosystems. In addition to flood control, wetlands sequester carbon and provide important habitat for wildlife.

Just a few years into the restoration at Deer Grove East, sandhill cranes started nesting at the preserve, said Linda Masters, a retired restoration specialist with Openlands.

“If you build it they will come,” Masters said. “Deer Grove quickly became a destination for birders because the birds just came back.”

Bobolink Meadow is now home to 142 different native and migrating bird species and has been recognized by the state as an Important Bird Area and Midewin is considered one of the most important grassland bird areas in Illinois.

“It’s been really amazing to see all the life that’s returned,” Stake said. “It doesn’t happen overnight, but we’re really starting to see the benefits of what was done.”