Strong winds from the south are causing Quebec's Richelieu River to swell again, pushing yet more water into the flood zone where communities have been paralyzed for weeks.

Winds blowing at 68 kilometres per hour were recorded in the region Wednesday and could lead to record-high water levels last seen May 23 when flooding peaked.

The river could rise by as many as 20 centimetres by the end of Wednesday, especially if it starts to rain, authorities said.

"We had an increase yesterday, we expect an increase today, and tomorrow there will be an increase [in water levels]," said Guy Laroche, spokesman for Quebec's civil security department.

Water levels will eventually fall, Laroche said, but it could be weeks before the situation returns to normal.

Weeks of flooding have tested people as never before, said Venise-en-Quebec resident Yvon Frédette.

"It's frightening. After so many days, we don't have the morale anymore. One week, two weeks, three weeks, now it's six weeks, and it's still the same. We don't see the end."

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Strong winds generated waves along the swollen Richelieu River. ((CBC))

Municipal leaders from the region are visiting the flood zone in turn, offering help.

Longueuil mayor Caroline St-Hilaire visited Saint-Paul-de-l'Île-aux-Noix Wednesday, vowing to help the town by providing technical support as needed.

Montreal mayor Gérald Tremblay visited Henryville and Sainte-Anne-de-Sabrevois Tuesday.

Merchants in the flood zone have banded together to advertise their goods and services, including tourist attractions, that were hit hard by weeks of flooding.

On Wednesday, Venise-en-Québec was expected to launch a "buy local" campaign.