‘Next to impossible to get people out’

Mud Lake resident says ‘lack of movement’ by Nalcor on emergency plan

Bonnie Learning bonnie.learning@tc.tc
Published on September 18, 2015

Dave Raeburn is concerned about what could happen to the village of Mud Lake if the North Spur dam at Muskrat Falls were to ever break. Raeburn believes there would virtually be no time for residents to get out of the area before the water reached the village. He says there’s been a lack of movement on Nalcor’s part as to what an emergency evacuation plan would look like in the event of a break.

©Dave Raeburn

While the dam at the North Spur is not yet completed, Dave Raeburn can’t help but feel apprehensive about what could happen to his little community.

Raeburn, a resident of the village of Mud Lake — located about eight kilometres southeast from Happy Valley-Goose Bay by boat or snowmobile — said there has been a lack of movement on what exactly the plan is for Mud Lake in the event of a catastrophic break in the North Spur dam at Muskrat Falls.

“The last time (Nalcor) came to Mud Lake to speak to us about an emergency evacuation plan was about two years ago,” claims Raeburn, who has lived in the village of 60 residents for 12 years.

“We haven’t heard anything since.”

The North Spur is a feature of the landscape that juts out into the Churchill River at the Muskrat Falls site, forming a partial natural barrier, which will be incorporated into the Muskrat Falls hydroelectric dam.

Raeburn said there would be little to no time to get residents out of Mud Lake should the North Spur ever break.

“I’d like to get a conversation going about the logistics,” he said. “We’re not talking about a trickle of water; we’re talking about a 20-feet high wall of water, moving at about 20-50 miles per hour, descending on Mud Lake within an hour.

“It would be next to impossible to get people out.”

Raeburn said no one can guarantee the dam will be 100 per cent fail-proof.

“No one can,” said Raeburn. “Whatever the percentage is, there is still the possibility of it happening.”

Nalcor responds

Gilbert Bennett, vice president of the Lower Churchill project, said while the design approach and design standards of the North Spur dam make the possibility of a break an “extremely unlikely event,”Nalcor will be sharing information with each community in the Upper Lake Melville area within the next two months.

“As we look at our emergency preparedness plans and our dam safety plans… it’s an important public safety issue, making sure that the residents of the area are aware of the facility and the consequences of a very unlikely event,” he said.

“That being said, the potential for an event does exist, therefore we would communicate that to the communities.”

Bennett said each of the communities would incorporate this event into their emergency preparedness plan.

“The first one starts with our coffer dam we’re building for construction purposes for our main dam. After that we’ll have another series of documents to deal with the facility after it goes in service and we build the reservoir,” he said.

Bennett said no matter the situation — whether it is a forest fire, natural flood, or a break in a dam — every community across the province should have an emergency preparedness plan ready to implement. He added Nalcor has contact information with each community, as well as contact and designated interfaces with emergency responders such as law enforcement, Fire and Emergency Services and other emergency agencies in case of a break in the dam.

“Then, that becomes an event that each of the communities would look at and say, ‘OK, I have an emergency plan. I have a communication plan for dealing with my residents.’ Then they would take it from there and notify their residents,” Bennett said.

Bennett noted simulations were undertaken to estimate the impacts of a breach at Muskrat Falls on downstream water levels during “fair weather” conditions and are on Nalcor Energy’s website for anyone to view at http://muskratfalls.nalcorenergy.com/wp-content/uploads/2015/07/Muskrat-Falls-Dam-Break-Study_for-web.pdf.

Inundation mapping corresponding to a dam break scenario is provided in appendices A and B of the document, noting water levels could begin to rise around 1.7 hours after a breach and could reach peak levels at around 7.3 hours.

Stabilization

Much of the major concern surrounding the potential for a dam break at the North Spur is the terrain on which it is being built.

Part of the spur is made of a kind of clay, which is prone to landslides if it gets wet. That’s raised concerns among critics of the project about whether the whole scheme is safe.

In a news release from January, Bennett noted Gilbert Newfoundland and Labrador Contracting would conduct stabilization work on the North Spur, building cutoff walls and changing the grading of the land to prevent landslides.

Now, Bennett said with regards to the engineering process at the North Spur, it’s one that Nalcor has been aware of for many years and was something that had to be looked at carefully.

“We’re building that facility to exactly the same standards as our other dams in the province,” he said. “We’re using qualified engineering consultants, we know it’s a major issue in terms of the facility overall. It’s been subjected to third party review by experts who are independent from the designer — we’ve had it looked at by third parties on multiple occasions; it’s been looked at by Canada’s independent engineer, who is there to advise the Government of Canada through the federal loan guarantee.

“I think the other point that’s worth making is that this is an integral part of the Muskrat Falls generating facility and if we look at the total project here, we’re spending $7 billion on the facilities associated with the project. And it’s incumbent upon us to make sure that that’s designed appropriately. It’s subject to intense inspection as we’re undertaking construction and that facility has a design life of 100 years.”

Bennett said there is no issue — from Nalcor’s perspective — in terms of the effort that’s gone into the design and construction of the asset.

But is the dam “rock solid” in terms of its stability, The Labradorian asked.

“Absolutely,” Bennett replied.

“Our facilities are engineered and operated from a very high standard. That’s integral to the stability and ongoing operations of the assets. We also recognize the safety of operating our assets and ensuring they’re constructed properly is an important question from the public’s perspective and one that we take very seriously.”

Bennett noted Nalcor complies with dam safety regulations and inspections that exist in the province and across the board.

“We’re members of the Canadian Dam Association, and they have guidelines for the operation of major facilities like this. …We share best practices and follow their guidelines as well,” he said.

bonnie.learning@tc.tc