Mayor of Paris Takes an Olympian Plunge in a Beautified Seine

After multiple delays caused by a combination of torrential rain and torrid domestic politics, Anne Hidalgo, the mayor of Paris, took to the cleaned-up waters of the Seine on Wednesday, fulfilling a promise that has become a symbol of the Paris Olympics.

With the Games just nine days away, on the kind of perfect Paris morning that inspires wonder, Ms. Hidalgo, a socialist who has pursued the ecological transformation of the city, stepped down into the murky river that will be a focal point of the Olympics.

A vast engineering project, costing some $1.5 billion over the past several years, has stanched the flow of sewage and industrial waste into the Seine. The result is a river that is clean enough for several Olympic events — including the triathlon and two 10-kilometer swimming events — to be held in it and for the opening ceremony involving a flotilla of boats carrying thousand of athletes to take place on it.

As crowds looked on from the riverbanks and bridges, Ms. Hidalgo, 65, in goggles and a black wet suit, swam the crawl rapidly downstream, accompanied by Tony Estanguet, head of the Paris Olympics Committee and a three-time Olympic gold medalist as a slalom canoeist.

After much rain in the past two months, the river is still flowing at about three times its normal speed.

Ms. Hidalgo’s initial plan to swim on June 23 was postponed because of the level of the river and the bacteria in it. The swim was put back to June 30. But that idea was blown out of the water by President Emmanuel Macron’s surprise move to hold snap parliamentary elections that day — a decision Ms. Hidalgo deplored. “Why ruin this beautiful moment?” she said, alluding to how the vote would encroach on the Olympics.