World Aquatics Championships: Open water swim off Sentosa postponed over water quality concerns

SINGAPORE: The start of the open water swimming competition at the World Aquatics Championships has been delayed by a day due to concerns over water quality off Sentosa, organisers confirmed on 15 July 2025.

The women’s 10km race, which was scheduled to begin at 8am on 15 July, was postponed to the following day after organisers determined that recent water samples exceeded the acceptable safety thresholds. The decision was announced just under eight hours before the race was set to start.

World Aquatics, in collaboration with the Singapore 2025 organising committee, said the move was made in the best interests of athlete health and safety.

“The decision was made in the best interests of athlete health and safety, which remains World Aquatics and the Singapore 2025 organising committee’s top priority,” the federation said in a statement.

The women’s 10km race will now take place on 16 July, the same day as the men’s 10km event.

A total of 69 swimmers were set to compete in the women’s race, which was meant to open the open water swimming segment of the Championships.

The water quality review involved World Aquatics, the local organising committee, the World Aquatics Sports Medicine Committee, and the Open Water Swimming Technical Committee.

Earlier samples collected before the race had met competition standards. However, tests conducted on 13 July found that water quality had fallen below acceptable levels.

Officials did not disclose the specific readings but confirmed that bacteria levels were the cause for concern. The results prompted an emergency review and the eventual postponement of the race.

Despite the delay, organisers stated that the rest of the open water programme remains unchanged. The men’s and women’s 5km events will go ahead on 18 July, followed by the 3km knock-out sprint on 19 July and the mixed 4×1,500m relay on 20 July.

Further testing and monitoring will continue throughout the competition to ensure that water conditions meet international safety standards.

This marks the first time Singapore is hosting the World Aquatics Championships, which officially opened on 11 July with the water polo tournament at the OCBC Aquatic Centre. The event features six disciplines: swimming, diving, high diving, artistic swimming, water polo, and open water swimming.

More than 2,500 athletes from over 200 countries and territories are participating in this year’s competition, which runs until 3 August.

The decision to postpone the Sentosa races highlights ongoing challenges in maintaining water quality for open water sports, especially in urban coastal environments.

Similar issues have affected major international competitions in recent years. During the 2024 Paris Olympics, the men’s triathlon was postponed only hours before its scheduled start after a pre-dawn inspection revealed pollution levels in the River Seine were too high for competition.

That incident underscored the persistent difficulties in ensuring clean and safe open water conditions even after large-scale remediation efforts. In Paris, authorities had invested €1.4 billion (S$2.09 billion) in a river clean-up initiative to prepare the Seine for Olympic events — a project aimed at reopening the river to public swimming for the first time in over a century.

In Singapore, World Aquatics and the local organising committee have stressed that athlete well-being remains their foremost priority. Regular water quality testing will continue at Sentosa to ensure that all upcoming events proceed safely and on schedule.