Overview and Background

The River Seine in Paris reopened to swimmers on July 5, 2025, marking the first opportunity for public swimming in the iconic waterway since 1923. This reopening follows a significant cleanup effort, costing approximately €1.4 billion (around $1.6 billion), aimed at improving water quality ahead of the Paris 2024 Olympics. The seasonal opening is seen as a major legacy of the Olympics, which featured open-water swimming and triathlon events in the Seine.

Three designated swimming zones are available: Bras Marie in the historic center, near the Eiffel Tower, and in eastern Paris. Each zone is equipped with changing rooms, showers, and beach-style furniture, accommodating between 150 to 300 swimmers. The opening comes as a relief during a heatwave affecting the region.

Key Findings

• First Swim in a Century: The Seine had been closed to swimming for over 100 years due to pollution concerns.
• Safety Measures: Lifeguards will monitor the zones, and daily water quality testing will assess levels of Escherichia coli and enterococci bacteria.
• Historical Significance: The push to reopen the Seine for swimming dates back to 1988, initiated by former Paris Mayor Jacques Chirac.
• Public Access: Swimming is free and open until August 31, 2025, for individuals aged 10 or older, depending on the location.
• Environmental Concerns: The Seine's water quality is subject to fluctuations, especially after rainfall, which can lead to temporary closures of swimming sites.

"It’s a childhood dream to have people swimming in the Seine," said Paris Mayor Anne Hidalgo during the reopening.

Officials emphasize that while swimming is now permitted, the Seine remains a challenging environment due to strong currents and boat traffic. Swimmers must undergo an assessment of their abilities before being allowed to swim independently, and fines will be imposed for swimming outside designated areas.

The reopening of the Seine reflects broader efforts to adapt Paris to climate change and improve the quality of life for residents, as noted by Mayor Hidalgo. With ongoing monitoring and improvements, the Seine aims to provide a safe and enjoyable experience for both locals and tourists alike.