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player ready...In the shadow of an imposing 27-foot earthen levee, a coyote slinks through tallgrass prairie. American coots, mallards and great blue herons dart around a shallow lake peppered with the flowers of the American lotus and flanked by the Illinois River.
The river was once one of the most ecologically and economically significant river systems in North America, supporting inland commercial fisheries and the continent’s highest mussel abundance. Emiquon Nature Preserve, 40 miles southwest of Peoria in central Illinois, offers a small glimpse into that past.
Outside the 6,000-acre preserve, the landscape starkly changes from brush to massive fields of corn and soybeans.
In the early 20th century, wetlands were drained for agriculture and disconnected from the thriving river and its adjacent low-lying land or floodplain — which was then farmed “intensively,” according to Randy Smith, Illinois rivers program director at The Nature Conservancy. “The whole site would have looked like that prior to restoration,” he said, pointing to the row crops neighboring the property.
Owned and managed by the conservancy, Emiquon has become the stage for one of the most ambitious floodplain restoration projects in the Midwest.
For scientists and environmentalists, the reasons to protect wetlands couldn’t be clearer: These ecosystems alleviate flooding intensified by climate change and support unique biodiversity. The latter is a crucial goal of the restoration project at Emiquon. A restored connection, Smith said, allows important nutrients and native species to once again move and flow more easily between the Illinois River and its floodplain.
“We can’t talk about conservation without talking about rivers” — and their surrounding wetlands, Smith said.
A hundred years later, the water and land are returning to their former abundance in Emiquon. But 30 million acres of unprotected wetlands remain at risk of being destroyed largely by industrial agriculture in the Midwest. Urban development and agriculture in Illinois have destroyed as much as 90% of the state’s original marshy, swampy land. And federal protections have been challenged in recent years.
In 2023, the U.S. Supreme Court stripped protections from inland wetlands in Sackett v. EPA, allowing private property development where there is no “continuous surface connection” to permanent bodies of water. After the decision, the University of Illinois at Urbana-Champaign found that roughly 72% of remaining wetlands in the state are no longer protected by the federal Clean Water Act.
In March, the Trump EPA announced it was seeking to redefine, and likely further narrow, its definition of protected waterways. Earlier this year, a federal judge in Iowa dismissed a lawsuit from a Chicago-based investor claiming that a federal provision that discouraged farmland owners from converting wetlands into cropland infringed on property rights.
“I would argue we don’t need to plant more corn in wetlands,” Smith said.
Interconnected nature
Pumps that had long been used to keep the land dry near what is now Emiquon were shut off in the 2000s after the conservancy began restoring the property in earnest, which allowed water to reform the lakes.
A crucial component of the project is the water control structure between the river and the floodplain that allows scientists to replenish and drain the wetlands in a way that mimics nature’s seasonal cycles.
On a recent fall day, the structure remained unused. Dried-up, cracked mud revealed the river’s connection to Emiquon.
“It’s been so dry. We haven’t had rain and — well, I guess it rained earlier this week, but prior it had been like 50 days or something,” Smith said. “So we are hopeful that we get a little raise in the river this fall, and we are hoping, sometime between now and next spring, about 2 feet of water we would like to move in (to the wetlands).”
Allowing water levels to rise in the preserve lets aquatic life such as plants and fish thrive, while lowering levels is good for the soil and the wetland plants growing in it, and lets migratory birds more easily prey on fish.
Two large culverts, some 7 by 8 feet, tunnel through the levee and have a door that opens and closes vertically, separating the river and the wetlands.
On the preserve’s side of the levee, water levels were high enough that day that opening the control structure would’ve allowed about a foot of water to flow out of the wetlands and into the river using gravity alone. Nearby, a station with two pumps — each with a capacity to remove 32,000 gallons per minute — can be used to more quickly lower water levels in the wetlands, whether for research, restoration or repairs to the levee. Scientists are trying to ensure its stability after years of water exposure and burrowing from beavers and muskrats, for the benefit of the preserve and nearby farms.
The structure is meant to preserve the health of both the Illinois and Emiquon, Smith said.
“So, when we connect to the river, all of these aquatic insects, the phytoplankton, the zooplankton, the seeds from all these other species are being released into the system, we are potentially helping end up in appropriate habitat,” he said.
Reconnecting the river with the floodplain is not one-and-done, however, especially as the Illinois River has proved particularly challenging to work with.
The reversal of the Chicago River in 1900, while hailed as a groundbreaking feat of engineering and an important public health measure to protect Lake Michigan’s drinking water, had downstream impacts that are less discussed. For instance, accounts at the time reported that the Illinois River almost doubled in size because of the increased flow from the lake.
“(That) makes a huge difference in the area that you could farm,” Smith said. “All of a sudden, it became necessary to build a levee in order to continue to get something.”
Joy Morton, founder of Chicago’s world-famous salt company, financed the levee and drainage tiles and ditches around the Emiquon area in the late 1910s.
“They basically kept (the wetland) pumped down and farmed for 80 years,” Smith said.
By 1926, almost all natural lakes and floodplain habitats near what is now Emiquon had been converted to farmland.
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“When it was a natural floodplain, it was getting all that rich sediment,” said Megan Baskerville, the conservancy’s Illinois agriculture program director. “If it’s not flooded, it’s really, really, really fertile ground.”
The reversal of the river also meant sewage and pollution from Chicago began flowing downstream.
“That essentially killed the Illinois River,” Smith said. “Zero oxygen, zero aquatic life, from Chicago to Peoria, for a number of years, decades.”
Even now, this pollution remains a concern for scientists. Allowing the river to flow into the floodplain is a tricky decision every time, he said, “because of the things that are associated with (it).”
Besides contaminants, this includes invasive species such as silver and bighead carp, some of which actually entered the preserve in larval form during a 2015 flood. They are particular in that they eat plankton from the base of the aquatic food chain, and thus can outcompete and starve native fish and mussels. Bighead carp are nearly nonstop eaters that regularly reach 40 pounds and can top 100 pounds.
But these invasives can’t breed in the preserve, Smith said, as they need periodic inundation with fast currents to trigger spawning and ensure their larvae survive. Under a managed connection, that doesn’t happen naturally, since the conservancy can more effectively control flooding with the water structure.
Rather, the concern is for common carp, another non-native fish that also breached a decade ago, and which breeds most aggressively in the wetlands. The species is known for destroying native vegetation, particularly rooted aquatic plants that serve as shelter for native fish species and food for waterfowl.
The preserve has tried to deal with the carp problem in creative ways through partnerships with government agencies and tech companies. For instance, researchers with the U.S. Geological Survey have sent out unmanned kayaks equipped with sonar to gather data that will allow anglers to target areas with high carp population concentrations and remove them.
Small larval carp can be easily swept in through screens when scientists are letting water flow into the preserve, Smith said. So it is easier to prevent adult carp from entering.
Some of the multipronged defense features against the invasive fish that will be included in the billion-dollar Brandon Road Interbasin Project on the Des Plaines River near Joliet were tested at Emiquon’s structure, such as the bubble and sound barriers.
A managed connection
Before restoration started, Smith recalled several experts saying, “You need to eliminate the levee. You need to go full connection. That’s how the river is going to be restored.”
“We didn’t do that. It was always about a managed connection,” he said. The water control structure allows for that.
But the project has not been without critics and skeptics, who have expressed concerns that restoring the flow between the river and backwaters could ruin the preserve. They have pointed 55 miles downstream at the conservancy’s smaller restored wetlands in Spunky Bottoms Preserve, where, after a 2013 flood overtopped a levee, scientists had to dig out a breach to allow the water to drain out.
“The whole system became fully connected to the river,” Smith said. “What we saw was an immediate collapse of our vegetation communities, of our fishery and an almost total loss of our positive migratory bird use. The ducks went away, the marsh birds went away, the shorebirds went away.”
This is why he says the ability to raise and lower levels in the wetlands with water from the river is a crucial aspect of restoration.
“The river is still so messed up and behaves so poorly; you cannot have that unmanaged connection,” Smith said. “We need to work with what we’ve got.”
There might never be a fully restored, unmanaged connection in Emiquon’s future.
“The floodplain will never look the same, the wetlands will never look the same,” Smith said. “We have a chance to — probably not undo, I don’t think that’s really in the cards anymore — but we have a chance to certainly, at least, rectify (that) somewhat.”
The river valley still has the capacity for more restored floodplain, most of which is currently degraded. Many backwater lakes and wetlands nearby are still farmland or on property owned by private waterfowl hunting clubs.
Nearby land is also owned by conservation nonprofits, as well as by state and federal agencies such as the Illinois Department of Natural Resources or the U.S. Fish and Wildlife Service, which manages the nearby Emiquon National Wildlife Refuge and Chautauqua National Wildlife Refuge.
Smith said the hope is to reconnect most of the floodplain with the river, not just a few wetlands.
“That’s like using a dialysis machine instead of a water treatment plant for a city,” Smith said. “Like, it’s not enough. The whole system needs treatment — not just one part of it.”
Smith said the team at Emiquon hopes its work can help guide similar large restoration projects or water management solutions around the country and the world, such as in Mississippi and Louisiana, and even as far away as South America and China.
“We’re still bringing folks out and showing them how we’re doing stuff here, and how that can be incorporated into (what) they’re doing,” he said.
The Illinois River still has a high ecological capacity; that is, it can support larger and more diverse populations of native species than it currently does.
“All is not lost. We still have a tremendous fishery. We still have mussel populations. We still have visiting migratory birds and these high-quality marshes,” Smith said. “There’s a lot of good there yet. But we’ve got a chance to push that over the top.”