Hydro-Quebec says dam at risk of failure holding up as police evacuate homes

FILE: The Hydro-Québec Building is a landmark of Montreal’s downtown. (Photo By llahbocaj from nyc – hydro quebec (2), CC BY 2.0)

MONTREAL – As a steady rain moved into Quebec Friday, authorities were keeping close tabs on a dam and a dike west of Montreal that were placing nearby residents at risk.

Provincial police were patrolling an area of homes and cottages along the Rouge River, about 140 kilometres west of Montreal, where 75 people were forced out when a dam to the north at Chute Bell was declared to be at risk of failing.

Meanwhile just to the east, Canadian Forces soldiers were dispatched to reinforce a dike in Pointe-Calumet that was threatening to give way and force 1,000 people from their homes.

In Grenville-sur-la-Rouge, provincial police Sgt. Marc Tessier said people left voluntarily, though some in more remote areas had to be airlifted by helicopter. Police planned to remain in the area to ensure no one returned.

“Our message is, if you’re in the zone, we’re going to ask you to leave,” Tessier said. “We don’t have a time frame for when they’ll (be able to) go back.”

Quebec public security officials issued an alert Thursday afternoon warning residents downstream from the Chute Bell dam on the Rouge River to leave their homes immediately. They had initially said about 250 people would be affected.

The evacuated area stretches about 18 kilometres south to the Ottawa River in Quebec’s Lower Laurentians region, about 140 kilometres west of Montreal. The alert is in effect until May 3.

The infrastructure was intended to withstand what officials call a millennial flood – an occurrence expected once in a thousand years.

Francis Labbe, a Hydro-Quebec spokesman, said those levels have been reached, and with rain in the forecast in the coming days, the Rouge River will likely rise.

“Right now everything is stable, it’s under control,” Labbe said Friday. “The problem is the rain that we are expecting in the next 24 hours or so, and we know this rain will make the flow of the river rise 30 per cent more than what it is right now.”

Eric Moisan, another utility spokesman, acknowledged that once the river flow surpasses the current 980 cubic metres per second, “we don’t know how the power station will perform.” He noted that a dam does not necessarily give way when the flow is excessive.

“It’s concrete. It’s very solid,” he said.

Hydro-Quebec has installed equipment and has employees on site to monitor the dam. Labbe said the 10-megawatt power station, originally built in 1915 but modified over the years, has been dormant for about a decade. He said other Hydro-Quebec dams are not experiencing the same stress.

Much will depend on the amount of rain, Labbe said. Environment Canada issued a rainfall warning for Quebec with the Montreal area expected to receive between 30 to 50 millimetres through Saturday.

“If the worst case occurs, we’re going to have lots of water, not just in the Rouge River, but in the Ottawa River and all the rivers around, and we think we might exceed the 2017 level two days from now,” he said.

Public Security Minister Genevieve Guilbault said heavy rain – particularly in the northern Outaouais and north of Quebec City – will cause water levels to the south to rise, and people living near bodies of water at risk need to be prepared.

She said Canadian Forces soldiers were being redeployed as needed, noting they’d been sent to Pointe-Calumet, a town northwest of Montreal that lies on the Lake of Two Mountains. They were working to reinforce a dike which, if it gives way, could put 1,000 people at risk and force them from their homes.

As of 1 p.m. Friday, Quebec’s Public Security Department said 3,148 residences had been flooded in the province, 2,362 residences had been cut off due to rising waters and 1,110 people had been forced from their homes.

In Gatineau, Mayor Maxime Pedneaud-Jobin warned residents Friday to prepare for the worst. “By Monday or Tuesday, we should exceed the highest levels of 2017,” he said, adding it could stay that way for up to two weeks. “What we will live through in the coming weeks, we’ve never experienced.”