Restoring Southeast Chicago Wetlands
Just fifteen miles south of downtown Chicago, on the city’s Far Southeast Side, sits historic Lake Calumet, the largest lake within city limits. And most people have never seen it.
For much of the late 19th and early 20th centuries, Lake Calumet was at the center of Chicago’s industrial empire. Unfortunately, that came at a cost. The surrounding wetlands were filled, dredged, and written off. Sites that weren’t paved over became dumping grounds for slag (a byproduct from smelting) and industrial waste. By the time the steel mills closed, much of the area had been fenced off, left degraded, and cut off from the communities that lived alongside it for generations.
Alongside local partners, the Wetlands Initiative is working to change that. Currently, we’re combining ecological science with hands-on engineering at two sites near Lake Calumet. The conditions at Indian Ride Marsh North and Square Marsh allow TWI to try new methods to tackle some of the most challenging restoration work in the region. The result will be more than just healthy habitat. It will be open, accessible green space on Chicago’s Southeast Side, and a new chance for a lot more people to see what wetlands have to offer.
Indian Ridge Marsh North
113 acres | restoration began: 2016 | Open to visitors
Indian Ridge Marsh North is a Chicago Park District site at the center of a vast wetland habitat complex that includes Indian Ride Marsh South, Big Marsh, and Square Marsh. This web of interconnected wetlands is part of what made it a priority for restoration, and part of what makes progress here matter far beyond the site’s explorable 113 acres.
When TWI and its partners (Chicago Park District and Audubon Great Lakes) began work in 2016, the site had a history worth noting. It was once home to a large colony of breeding Black-crowned Night Herons, and it holds a unique place in botanical history. It’s also where the North American fairy lantern (Thismia americana), the only flower to be endemic to Chicago, was discovered and documented. This incredible past made Indian Ridge Marsh North’s degraded condition all the more unacceptable and its restoration compelling.
Did you know?
Thismia americana is Chicago’s phantom plant. Discovered in 1912 by University of Chicago graduate student Norma Pfeiffer in Indian Ridge Marsh, the tiny, nearly translucent flower hasn’t been seen since 1916! Although broadly considered to be extinct, many believe it still could be found in Chicago’s Southeast Side. Over the years, TWI has organized community hunts for the elusive plant at Indian Ridge Marsh North. So far, no luck. But the search continues!
Aside from reestablishing hemi-marsh, one of TWI’s most significant contributions at Indian Ridge Marsh North is a new shoreline modification technique developed and successfully tested here in 2021.
When a shoreline drops steeply from land into deep water, there’s no shallow zone where emergent marsh plants can take hold. Basically, no shallow zone means no hemi-marsh. At Indian Ridge Marsh, TWI used sediment and soil to reshape the harsh banks of slag and rubble into gradual slopes, creating the shallows marsh plants need to thrive. It’s a straightforward idea with powerful results. Marsh Bird monitoring is already showing the returns. In short, biodiversity is coming back.
Learn more about marsh bird monitoring at the Marsh Bird Monitoring Hub at Audubon Great Lakes
Square Marsh
184 acres | restoration began: 2023
For decades, Square Marsh was fenced off from the communities that surround it, used as a dump site and left to degrade while the rest of the Lake Calumet area changed around it. The water turned brown, invasive carp took over, and native plants disappeared entirely. As TWI executive director Paul Botts puts it, “no one living has ever seen Square Marsh as anything but a muddy mess.”
That’s exactly why it matters so much to get it right.
Square Marsh is a remnant of historic Lake Calumet itself, making its restoration one of the most significant opportunities in the entire Calumet effort. At 184 acres, it’s also one of the largest. TWI is working here in partnership with The Nature Conservancy and the Illinois International Port District. It’s a partnership bringing together ecological expertise and the institutional access needed to tackle a site that has been off limits for generations.
Work is in its early stages. Phragmites treatment is underway and soil analysis is informing next steps. Long-term, TWI envisions restored habitat, new public access, and trail connections linking Square Marsh to the broader network of nature spaces taking shape around Lake Calumet.
For a site no one has been able to visit in decades, that’s no small thing.
Returning to What Once Was
What’s happening at Indian Ridge Marsh North and Square Marsh isn’t just ecological restoration. It’s the return of land that was taken out of public life for generations, given back as green space, open water, and thriving habitat. Lake Calumet is still largely unknown to most Chicagoans but these two sites are starting to change that.
The Wetlands Initiative is working closely with Audubon Great Lakes, the Chicago Park District, and other partners on a conservation action planning effort that will inform restoration and management of important remnant wetland sites in the Calumet area.