Illinois drained two lakes for farmland for about 70 years; after conservationists bought Emiquon in 2000 and began restoring the wetlands, spring waterbird counts exceeded 119,000

For most of the 20th century, the area of floodplain along the Illinois River near the tiny town of Havana looked like any other Midwestern corn and soybean farm. Yet hidden within those rows of crops was land that had once held two of the most productive natural lakes in the Illinois River valley. Thompson and Flag Lakes were drained and used for farming for around 70 years before conservationists were able to intervene.

Thompson and Flag Lakes remained drained and farmed until 2000, when The Nature Conservancy purchased the 7,000-acre parcel, now known as Emiquon Preserve, and began re-flooding the area. Long-term records kept by the Forbes Biological Station, an arm of the Illinois Natural History Survey, later helped document how the site changed before and after restoration. At the time, very little was known about whether wildlife would return to land that had been cultivated for so long.

Since the restoration began, spring waterbird counts have exceeded 119,000, including 20 duck species, three goose species, three swan species, and 23 other non-waterfowl species. Autumn counts have also exceeded 90,000. These numbers mark one of the more notable waterbird recoveries documented along the Illinois River in recent decades.


A farm field that used to be a lake, and is now a lake again

It was not simply a case of switching off a few pumps. From the start, the Emiquon project was seen as a true restoration experiment. According to a 2017 paper titled “Application of key ecological attributes to assess early restoration of river floodplain habitats: a case study,” published in the journal Hydrobiologia, ecologists monitored key indicators such as water quality, native plant cover, and fish and bird populations. The restoration led to an increase in wetland habitats, with the site growing from 630 acres to 4,747 acres by 2010. In 2012, the site was recognised as a Ramsar Wetland of International Importance.

Why this story reaches beyond Illinois

Whilst this may seem like a local fact, it is actually extremely important. Over half of the wetlands in the US have been lost since colonial times. The Mississippi and Illinois River systems were highlighted decades ago as a priority for floodplain restoration in the country by the National Research Council.

The Emiquon site has become a real test site for floodplain restoration, with over a hundred restoration permits issued between 2006 and 2015 to scientists from over 20 organisations across 3 continents to study how restoring a river and allowing it to interact with its floodplain works. This is a really positive message for the youngsters who have often associated environmental stories with negative outcomes.

What the press releases might have missed

Despite the success of the Emiquon site, this is not a self-sustaining project. Whilst the restoration has been successful so far, the paper highlighted that the site is at risk of degradation. A separate 2017 study titled “Why experiment with success? Opportunities and risks in applying assessment and adaptive management to the Emiquon floodplain restoration project,” by Sparks et al., published in Hydrobiologia, notes that issues with aging infrastructure controlling the water and invasive species can occur if the site is not actively managed. This shows that whilst nature does have the ability to bounce back, it can only do so if humans invest in it. That lesson may be less attention-grabbing than the recovery itself, but it is likely the most instructive part of the story.