From polluted past to global prize: Chicago River honoured with Thiess International River Prize

• Friends of the Chicago River named winner of the 2025 Thiess International River Prize at the International River Symposium in Brisbane.

• Once too polluted to paddle, the Chicago River is now swimmable thanks to four decades of advocacy, restoration and community action.

• The Thiess International River Prize is the world’s most prestigious award for river restoration, celebrating projects that deliver lasting ecological, social and economic benefits worldwide.

Friends of the Chicago River has been crowned the winner of the 2025 Thiess International River Prize at the International River Symposium in Brisbane, earning global recognition for its transformative restoration of the Chicago River. Once too polluted to paddle, the Chicago River is now on track to become swimmable thanks to decades of restoration led by Friends of the Chicago River.

Once heavily polluted, fenced off, and long considered unsafe, the Chicago River will be home to its first open-water swim in nearly a century on September 21. This extraordinary milestone is possible thanks to decades of dedicated work by Friends of the Chicago River to protect and restore the river’s ecological health for people, water, and wildlife.

Established in 1999, the Thiess International River Prize is the world’s most esteemed award for river restoration and management. Valued at A$100,000, the biennial prize serves not only as a financial award but also as provides a global platform that amplifies winners’ work and supports their ongoing impact.

Chair of the International River Foundation and Executive Chair and Chief Executive Officer at Thiess, Michael Wright, said the achievements of Friends of the Chicago River demonstrated how urban rivers can be reclaimed when communities, science and government work together.

“The Chicago River's transformation is evidence of what’s possible when communities, scientists and government unite behind a shared vision,” Mr Wright said.

“Their success highlights a legacy of ecological renewal and civic pride that can inspire cities worldwide.

“I want to sincerely thank all of the river restoration groups who applied, and give special recognition to this year’s finalists for the incredible impact they are making.”

Friends of the Chicago River, founded in 1979, and their success can be measured in species of fish, miles trail, and people in, on, and along the water. Friends restored vital habitat for wildlife, including river otters, expanded public green space, and successfully shaped water policy.

“This tremendous honor recognizes the hard work, innovation, and deep commitment of our team, partners, and tens of thousands of members and volunteers who believe in the urban rivers as natural wonders of health, biodiversity, sustainable economy, and community connection," said Margaret Frisbie, Executive Director of Friends of the Chicago River since 2005.

“Being honored internationally confirms that what we’re doing here in the Chicago-Calumet River watershed has global significance. It shows that urban rivers—when championed—can be restored for all people, water, wildlife, and contribute to climate resilience. We are profoundly grateful to the International River Foundation for the extraordinary recognition of our work.”

The Thiess International River Prize has been awarded since 1999, celebrating over 20 transformative river projects worldwide, including the Danube, Rhine, Lake Eyre Basin, and San Antonio River.

This year’s finalist group included Cumbria Rivers of the UK, Klamath River in the US, and the Vjosa River of Albania—all recognised for pioneering watershed-scale interventions.

The announcement was made during the 26th International River Symposium, held this week at The Star Brisbane, where hundreds of delegates from around the world met to explore the theme: River Revolution: Accelerating Solutions for Climate Resilience.