Dam at risk of failure is holding up after Grenville-sur-la-Rouge evacuated
Published Thursday, April 25, 2019 4:32PM EDT
Last Updated Saturday, April 27, 2019 8:26AM EDT
Steady rain moved into Quebec Friday as officials keep close watch over the Bell Falls Hydro Dam that forced dozens of residents in Grenville-sur-la-Rouge to evacuate their homes.
Environment Canada issued rainfall warnings on Friday for all areas north of the St. Lawrence River, Montreal and the region from Vaudreuil to the American border.
In many regions, up to 60mm of rain will fall over Friday and Saturday, which is expected to increase the snowmelt and cause more flooding.
As for the evacuation in Grenville-sur-la-Rouge, about 60 people left by road while 15 others were taken out via helicopter. Officials initially said 250 people were subject to the evacuation order, but it turned out that only 75 people had to be ordered out of town.
Residents said water has flowed over the dam for several days as water levels on the Riviere Rouge hit what Hydro Quebec considered a thousand-year high point.
"This specific dam was designed for a flood once every thousand years so we've reached that level," said Simon Racicot-Daignault, director of production for Hydro-Quebec. "We're confident at that level it's going to hold up. The question is how much more rain are we going to get over the next few days."
Quebec's Public Security Minister ordered the immediate evacuation of the 18-kilometre-long region, from the dam to the Ottawa river, telling residents they needed to get out immediately and would have to stay away until at least May 3.
"We are doing door to door, Sureté du Quebec is door-to-door to make sure that all people who are there are evacuated as a preventive measure. It is important to reassure all people that we are taking every action to make sure that all people who were there are evacuated," said Genevieve Guilbault.
Residents said police told them to leave without taking anything with them.
"The cops that are evacuating right now, down on Terrevet St. they're just busting open the doors and [saying] everybody out right now, don't shut your door, don't turn your lights off, just leave as fast as you can," said Matthew Paquette.
SQ officer Marc Tessier said officers were patrolling the area to ensure nobody tried to return.
"Every time we do evacuation it's for safety. Because if you're isolated and if you need assistance quickly you're not going to have that. That's why we're asking people to leave, that's the main reason. If something happens you're going to be stuck there and no help is going to be able to get to you," said Tessier.
The town's mayor, Tom Arnold said that he felt like his heart had stopped when the fire chief told him the dam had broken -- but that turned out to be incorrect and the dam is still intact and the water flow has decreased in the past day.
"It's gone down now, I think we're running about 940 cubic metres per second, and they predict it could go up as much as 1300 cubic metres per second. The dam was designed for a maximum one-thousand-year flood of 960 cubic metres per second. So yesterday it went above that maximum, came back down this morning, but it's probably on its way back up again," said Arnold.
Hydro Quebec expects the water volume to increase by about 30 percent in the next few days as more rain hits the area, and the level of the river to rise by 70 cm.
The utility says the dam that was built in 1915 may be fragile, but it does not expect the dam to completely collapse.
About 30 homes in Grenville-sur-la-Rouge are occupied year-round, while another 25 to 30 homes are seasonal cottages.
People living in the evacuated homes who did not have anywhere else to go spent the night in the Lachute Arena, which is serving as a shelter for flood victims.
The Public Security Ministry is warning everyone in the region to stay away from rivers, valleys and low-lying areas, and to follow instructions of local authorities.
The Riviere Rouge empties into the Ottawa river a few kilometres upstream from Hawkesbury and Grenville.
Officials in Rigaud, which is about 30 km further downstream, said that even if the Bell Falls Dam collapses the overall increase in water levels in the Ottawa river would be one to two cm.
Flood waters rise
On Thursday Guilbault toured the Lachute area, northwest of Montreal, where flood waters on the Riviere du Nord have risen in recent days.
She said she was impressed with the level of preparation in smaller communities and was satisfied that the number of people on the ground working on flood relief -- which includes nearly 1,000 Canadian soldiers -- was sufficient.
Guilbault added she wouldn't hesitate to ask for more help if necessary.
Roads, schools closed in Montreal
The rising water levels forced several roads in Montreal's West Island to close, including some that are far inland.
Among the closed roads are Senneville Rd., Anse a l'Orme, sections of Pierrefonds Blvd. and Gouin Blvd., Gratton St., and the northern tip of St. John's Blvd.
Several roads on Ile Bizard are also closed, as is Lalande Blvd. in Roxboro.
On Friday College Charlemagne in Pierrefonds issued a notice that it would be closed because of the flooding on Gouin Blvd. At this point the school expects to reopen on Monday.
Bridge to Ile Bigras closed
High water levels in Laval forced the closure of the bridge connecting to Ile Bigras Thursday, meaning people living on the island can no longer enter or leave by car.
Police put the barrier in place at 11 a.m., forcing residents who wanted to leave to walk on the neighbouring bridge that's under construction.
“We're kind of in survival mode. We're trying to just prepare as much as we can,” said resident Mark Leblanc.
Leblanc’s property isn't flooded but he knows that could very well change.
“Our house is in a valley between the other side of the street, which has ditches, and the river. So if the ditches which hold the rising river level, If that overflows just by a millimetre, then it all trickles down into our property and eventually it will fill up,” he said.
While it’s the second time in three years Leblanc has to worry about water infiltration, he said there's no way he would take a $200,000 buyout.
“Definitely not. This house is worth much more than that. It would be at a tremendous loss,” he said, adding that he hopes to see more permanent solutions put in place.
Army working in Laval
Meantime the army and city workers are trying to seal off the nearby waterfront community of Laval-Ouest.
“We're going to be here probably all day. And if they need help in other areas, it's probably going to be tomorrow, after tomorrow,” said Sgt. Charles Fontaine.
With the help of a private company, large inflatable dikes have been put in place to prevent water from intruding and pumping out any that has already made its way in.
“Inside the barrier, we have a design – it means it stops the barrier to go from side to side. So it's inflated with water, and the weight of the water makes the barrier stable and stuck on the ground,” explained Laurent-Rene Campeau of Atlas Dewatering. “As soon as we close that section and start to pump, it's roughly eight hours and the water is going to go down.”