Overview

• Three lifeguarded swim zones opened July 5 for the first public bathing since 1923 under a €1.4–1.6 billion cleanup program.
• Heavy rainfall on July 6 triggered red flags and shut the sites as Paris’s 19th-century sewers risk overflow and bacterial contamination.
• City officials test daily for E. coli and Enterococci and display green, yellow or red flags to signal when swimming is permitted.
• The infrastructure upgrades connected 20,000 homes to sewers, expanded treatment plants and built rainwater reservoirs to curb stormwater overflows.
• Swimming remains free through late August with capacity capped at about 1,000 bathers per day, subject to weather-driven water-quality checks.