MONTREAL - A Transports Quebec warning has been lifted for flooding on Highway 20.

The agency warned of lane closures and encouraged drivers to consult or check the Transports Quebec Twitter account before taking the highway.

At 10 p.m. on Thursday, Transports Quebec said water was accumulating on the westbound lanes of the highway, but the eastbound lanes were open. 

As has happened before on at least two occasions, sudden and persistent rain built-up on the new stretch of highway between Angrignon Blvd. and the Saint-Pierre interchange.

Overflow basins in the area are temporary, and pumping is insufficient to contain the water, Transports Quebec told CTV on Oct. 2, when the highway first flooded. On that day, 40 mm of rain fell over two hours. Despite the addition of pumps, the highway flooded again on Oct. 17, when a violent storm lashed the city and knocked out power across the province.

On Thursday, as rainfall prompted the city of Montreal to postpone Halloween, 50 to 80 mm of rain would fall into Friday morning, Environment Canada forecast. High winds were also expected.

In the summer of 2020, when permanent retention ponds and pumping systems are built, the risk of the highway flooding will be "virtually zero," Transports Quebec said.