Only 21 people attended the public information session to outline plans for the decommissioning of the Providence Dam at Marshall Lake hosted by the Ministry of Forests, Lands and Natural Resource Operations (FLNRO) on June 26.
Dan Peterson, Thompson Okanagan director of resource management, and Mike Burwash, section head for Fish and Wildlife, were joined by Fisheries biologists Tara White and Brian Janze from Penticton, who delivered the bulk of the presentation.
According to the government, Providence Dam no longer meets provincial or Canadian dam safety standards and has outlived it’s original purpose to supply water to the Phoenix Mine and that a dam failure has the potential to impact the entire community of Greenwood. So to ensure the public’s safety, the dam is being decommissioned.
The plan calls for a 46-metre opening at the top of the 30-metre high dam with sloping sides down to a four-metre spillway at the base (the dam is currently 110 metres long).
This is the minimum amount of removal that will meet dam safety regulations and allow the Ministry of Environment Fisheries Section to be clear of their responsibility for maintenance and liability.
White said Providence Dam has been designated a high consequence dam, with potential for loss of life, substantial economic, social, environment or cultural loss if the dam were to fail.
Midway resident John Greaves questioned the high consequence classification, suggesting the potential for failure is low and could be mitigated.
“This keeps coming up and I feel like I am being lied to,” said Greaves, who regularly posts on the Marshall Lake Stewardship Group Facebook page.
In 2011, the City of Greenwood was given a year to try to put together a plan to take over the licences. “In June 2012 local government responded it was not feasible and they were not capable to take on the dam,” said White.
Last fall the lake was pumped down to the natural level of storage, reducing it from 6.5 hectares in size to 2.6 hectares – the depth changing from 13.85 metres to 7.7 metres.
“Essentially what Dam Safety are looking for is a structure that will not fill up or block in any way to cause any backup of water what would give out in any heavy storm event,” said Janze.
At the request of neighbouring property owners, the ministry sought cost estimates for both the 46-metre breach and for removal of the entire dam. Janze put the figure for total removal at “probably $1 million,” whereas the preferred 46 metre breach comes in at under $200,000. The cost of the lake drawdown last year was put at $100,000.
Greaves and others at the meeting questioned the costs to keep the dam versus the cost to decommission it.
“One of the key considerations is that we want people to be able to maintain recreational activity at Marshall Lake,” Janze said as he gave an overview of site rehabilitation.
“I don’t want to see you guys just walk away from it,” said Greenwood Mayor Nipper Kettle. “In the end we need something up there. Because there are quite a few people in the community that like that place. They go up there and use it on a regular basis. I just want a commitment from you guys that there is going to be something left there so the citizens of our community will have something.”
“That’s our agenda,” replied White, “to maintain the natural storage and continue to stock it to provide recreational opportunities. Rehabilitate the area for recreation. There will still be a recreation corridor there.”
“Once we get out from under this licence and the maintenance costs, we can spend more for the Fisheries,” said Janze. “We have 300 lakes in the region with less than $100,000 a year in the budget.”
He said that because of the high consequence classification, two staff members must drive from Penticton each month to do an inspection and every seven years, an engineering review is required at a cost of $30,000. “It doesn’t make a whole lot of sense to maintain it.”
Jim Forshaw, who said he spent his career in the mining industry building and maintaining tailings dams, called the decommissioning of the dam a foregone conclusion.
“These poor folks are just doing what they are told to do,” he said after the meeting. “Greenwood needs every little bit of help it can get. Anything that can make it better, can bring tourists and have a nice place to camp.”
In May, FLNRO public affairs officer Brennan Clark said that decommissioning is scheduled to take place in August and September 2013.
– Pat Kelly is reporter for the Boundary Creek Times