Paris Mayor Anne Hidalgo took a historic swim in the Seine River on Wednesday, marking the culmination of a significant cleanup effort just in time for the 2024 Summer Olympics. Joined by about 100 officials, athletes, and local residents, Hidalgo’s swim celebrated the improved water quality, which has been deemed safe for Olympic events.

For the past century, swimming in the Seine was banned due to pollution. Efforts to clean the river have been ongoing, with the most recent and substantial initiative costing €1.4 billion. This included the construction of a large underground water storage basin to capture stormwater and prevent bacteria-laden wastewater from entering the river. The system, operational since June, is a key component in ensuring the river remains clean during the Games.

Despite fluctuating pollution levels earlier in the year, recent tests have shown significant improvement, allowing triathlon and marathon swimming events to be held in the Seine. Olympic organizers, however, have contingency plans in place to postpone or relocate events if heavy rains cause water quality to deteriorate. Tony Estanguet, president of the Paris 2024 organizing committee, expressed confidence in the preparations, noting the transformative impact of the Games on the city’s infrastructure.

The cleanup effort has also positively impacted local wildlife, with over 30 species of fish now present in the Seine, compared to just three in 1970. French Sports Minister Amélie Oudéa-Castéra and Olympic triathlete Léonie Périault have also endorsed the improved water quality, with Périault participating in test events without issue.

While challenges remain, particularly with unpredictable weather patterns, the successful cleanup of the Seine represents a significant achievement for Paris. As the city prepares for the opening of the Olympics on July 26, the Seine stands as a symbol of environmental progress and urban renewal.