Picture a garden hose. If you’ve got a leak spraying water all over the place, you’d run back to the valve and turn the water off so you could deal with the problem. In a hydropower facility, a series of gates serve a similar purpose as a hose’s valve. If something is happening in the facility and you need to shut off the flow of water, you’d roll down these gates—a move that protects other equipment in the facility and the people who need to go inside to fix and maintain it.
This important role is why “intake operating gates” need to be kept in tip-top shape. At Arrow Lakes Generating Station, its six gates are in the process of being refurbished—ensuring they can continue to do their vital job.
“It all goes to keeping the facility reliable and making sure that the critical equipment works when we need it to,” says Matthew Tonner, Senior Dam Safety Engineer at the Trust. “Specifically for the gates, it comes down to protecting the assets and protecting the people that work downstream of them.”
Located 400 metres from existing Hugh Keenleyside Dam on Arrow Lakes Reservoir near Castlegar, Arrow Lakes Generating Station makes use of water that would otherwise be spilled by the dam, generating enough power to supply 80,000 homes.
During annual inspections, staff noticed that its gates were starting to age. The biggest issue was the coating that covers the gates’ underlying steel structure. It was degrading, which meant that water was able to access each gate, causing corrosion.
Fixing the six gates has been a multi-year process. First, the facility purchased one new gate. During an annual maintenance period, it replaced one of the six failing gates with this new one. The removed gate—which weighs many tonnes—was then sent to an enterprise in Quebec to be refurbished.
During the next annual outage, the refurbished gate replaced yet another of the failing gates, and the cycle was repeated. All six gates should be refreshed by spring 2025.
Why not simply replace them instead of fixing them up? One reason is cost—refurbishing a gate costs about 60 per cent of what a new one does. Plus, most of the gate components can be reused, so this tactic minimizes waste.
Tonner says that the process has been “going smoothly. Three or four years ago, we had never removed a gate before, and now it’s becoming a pretty standard operating procedure for the crew. They know what to do.”
Once this project is done, they won’t need to do it again at Arrow Lakes Generating Station for two or three decades. Another facility may be on the horizon for a gate refurbishment—Brilliant Expansion Generating Station—but not for 10 years or so.
Planning ahead and preventing failures before they take place is a crucial step when it comes to ensuring that such facilities continue to function with minimal unplanned outages and costs. This is important because so many people benefit—not just from the electricity itself, but from the operations’ broader positive effects.
Together with Columbia Power Corporation, the Trust owns four hydropower facilities. Columbia Power’s half of the income streams back to the Province and therefore to all residents of BC. The Trust’s half supports its work in the region, including the delivery of programs that strengthen well-being. Such impact provides a solid reason to make sure the facilities work as flawlessly as possible. When it comes to stable operations, Tonner says, “Good maintenance programs are the best strategy you can have.”