Safety review proposed for Spruce River Dam

This agreement, however, expired in 1995.

“The agreement expired in ’95, but there is an agreement that we would follow the intent of that agreement [from 1960] until a new was established,” Stolle said, and added they’re working on a new agreement with the WSA over the next year.

He explained this agreement is because they don’t have the expertise operate such a structure, saying “We’re not the dam business.”

Although the WSA decides when and how much water to release, Stolle said they must still work with the water levels identified within the agreement. Should the WSA want to go outside those limits they must consult with Parks Canada.

The decision made to release water this past spring that resulted in flooding downstream in places like Cumberland House was a smart one said Jim Reeves, strategic asset management advisor for Western northern Canada Parks Canada Agency.

Reeves said in light of the situation, releasing some water was needed in order to avoid breaching the dam.
“It has been designed in order to be able to retain what is called 40,000 bam … which is equivalent to about 40,000 cubic metres of water,” Reeves said.

Luckily, the he explained the dam is actually in good shape and hasn’t required any reconstruction work since construction, “in fact the dam, its structural integrity, is very good at this time.”

He said dams “historically” can stand for hundreds of years, he said. He described the earth-made structure as composed of a clay core, an impervious layer that prevents water from migrating through.

Although no reconstruction work has needed to take place, routine maintenance work is required.

“Most of the maintenance work that has been vegetation removal,” he said. “Also crest increases in height, like they’ve increased the height of the crest of the dam, the embankment, but other than that there there’s no requirement to do anything else. Earth-filled dams generally don’t need too much maintenance on them.”

Despite not needing much work over the years, Reeves said they are planning review the safety of the structure.
“I have planned what’s called a Dam Safety Review of the dam this year,” he said, but according to him, the timing has nothing to do with the recent flooding in the province and is purely coincidental.

“It was schedule. I’ve been doing them for Western Northern Canada for about three, four years now, so this one was schedule for it,” he said.

“It just so happens that we did have our dam engineer look at this dam in 2007 I believe it was … and he came back with an assessment that ‘dam was in good shape.’”

This review is expected to be completed by the end of the year, and is important in terms of ensuring the major components like the embankment and the concrete spillway, in this case, are not being compromised.

“I currently have put together a proposal for that and I will be putting that out to solicit services from a consultant. And the Dam Safety Review will cover a number of different components of the dam. It will address any sort of failure consequences, so what they do is essentially model what will occur if the dam did fail,” he said.

It will also review the operation and maintenances practices presently being conducted on the dam, so they will look at what WSA is doing and as well as develop an emergency preparedness plan and emergency response plan.

These plans will be created after reviewing models of the structure. Reeves said whoever conducts the review will be taking a look at catchment areas and taking a look at what would happen if the dam would overtop or even if the dam filled completely, what would happen downstream. This helps them make the emergency plans.

After that, it will be presented to the WSA.

“The park and WSA will be very intimate on the development of [the plan], so that all parties are aware of what’s being stated.”

sstone@panow.com

On Twitter: @sarahstone84

by Sarah Stone

Safety review proposed for Spruce River Dam

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