Paris reopens this iconic spot to public after nearly 100 years. Courtesy, Olympics

The River Seine reopened in Paris on Saturday morning for the first time since 1923, offering locals and tourists a welcome respite after scorching temperatures.

Three sites along the banks of the Seine in the city will be able to welcome over 1,000 swimmers daily until August 31, local officials said.

"We're especially happy to have proved the sceptics wrong and to be able to deliver on the commitments we initially made, on something that was very big and very complicated to achieve," said Pierre Rabadan, Paris deputy mayor for the Seine river.

The reopening of the Seine for public swimming follows efforts by authorities to improve its water quality so it could be used for Olympic events last summer.

Authorities invested in expanding the sewer network to cover tens of thousands of homes, modernising water treatment plants, and building large reservoirs to hold rainwater and reduce sewer overflows during storms.

Although some Olympic training events and the men's triathlon were disrupted due to health concerns from heavy rainfall, events in the Seine later proceeded, boosting trust in the river's safety for public use.

Throughout the swimming season, water quality will be monitored daily. Green and red flags, similar to beach alerts, will signal whether swimming areas are safe or closed.

As well as the three sites within Paris, 14 swimming areas outside the capital's boundaries will be set up on the Seine and the Marne rivers. Two of those already opened on the Marne in June.

(With agency inputs)