Quebec’s Public Security Ministry is warning that the hydroelectric dam at Bell Falls on the Rouge River in the western Laurentians region is at risk of failure.
The ministry is advising anyone down river from the dam to evacuate the area immediately and stay far away from waterways, valleys and low-lying areas.
Hydro-Québec said the dam has reached its capacity, but as of 5 p.m. Thursday it had not broken.
Francis Labbé, a spokesperson for the utility, said its engineers believed the dam would not break, but that current water levels and expected rain legally obliged them to give an evacuation order for those downstream.
Quebec provincial police said round 30 residences are being evacuated, and some 250 people are being ordered to leave the area.
If the dam ruptures, it will take around 45 minutes for floodwaters to reach those buildings under the evacuation order, police said.
Police said they are using “all the means at their disposal to ensure people’s safety.”
“We are asking residents of areas affected by forced evacuations to co-operate with the authorities,” the Sûreté du Québec said on Twitter.
Dam built to withstand once-in-1,000-years flood
Francis Labbé, a spokesperson for Hydro-Québec, said the 10-megawatt dam was built to withstand water levels in the Rouge River that experts expect might occur once in 1,000 years.
“The problem is we’re at this level now,” Labbé said. “And we do know that in the next 24 hours or a bit more, we’re going to receive a serious amount of rain.
“Because we’re convinced that we’re going to get much more water in this river than the dam is built to support, in this situation we cannot do anything else but warn the people that they should evacuate for their own safety.”
Highway 50 closed at Grenville
Transports Québec has closed Highway 50 in both directions at Grenville-sur-la-Rouge. That highway, which links Gatineau to Highway 15 at Mirabel, crosses the Rouge River about 16 kilometres downstream from the dam, where the Rouge empties into the Ottawa River.
The evacuation order for the Grenville-sur-la-Rouge area comes as large swaths of Quebec and neighbouring eastern Ontario are dealing with spring floods.
Bell Falls, or Chute-Bell, is about 23 kilometres northwest of Grenville-sur-la-Rouge, Que., which is on the north side of the Ottawa river, across from Hawkesbury, Ont.
This story originally appeared on CBC