TransAlta is planning a $20 million upgrade to its Pocaterra Hydro Facility in Peter Lougheed Provincial Park next year.
Representatives with the company were on hand for an open house at Boundary Ranch in Kananaskis Country on April with details of the upgrade.
Project manager Roger Drury explained the work proposed is to replace the penstock at the hydro facility, which dates back to 1955 and is made of wood.
The penstock is a 1.37 kilometre long pipe that diverts water from its source to the hydro facility.
“The reason we are replacing it is because over time the wood penstock joints get worn and it leaks water,” Drury said. “We have done maintenance over the years, but we have hit the point that it needs to be replaced.”
The water leaking out does not significantly affect the power generation of the facility, he said, but it presents a risk of eroding the earth away from under the pipe.
At 11 feet in diameter, the penstock sees 30 cubic metres of water flow through it per second while the Pocaterra facility generates 15 megawatts.
It was built a distance away from the water source because the vertical elevation gain increases the amount of power generated.
During construction, which is expected to be underway in the fall and take up to a year to complete, the existing penstock will continue to function until the new one is ready to be hooked up.
That process of switching over to the new pipe is expected to take three months.
The new pipe will be constructed of either steel or glass-reinforced plastic, depending on cost and tenders.
Drury said TransAlta is deliberately trying to reduce the affect this construction project will have on the surrounding area by limiting the area needed to be cleared to 18 metres. Typically, pipeline construction requires clearing up to 30 metres, he added.
Currently, TransAlta is engaging stakeholders and the public while going through permitting approvals with several different government agencies including Alberta Environment and Fisheries and Oceans.
Golder and Associates were hired to complete an environmental impact assessment and do ongoing studies.
Golder fisheries biologist Jeff Brezenski said the assessment looked at climate and air quality, hydrology, fish and fish habitat, soils and terrain, vegetation and wildlife.
He said accurate flow data on the river is needed to ensure enough water is bypassed during the time the penstocks will be switched over to maintain flows for fish, habitat and recreational uses.
“It is not expected to have any noticeable impact,” he said. “We have to maintain flows immediately downstream.
“There is fish, fish habitat and other wildlife that rely on water to be there.”
Brezenski said one benefit of the project is having the new penstock buried underground.
The current penstock is above ground and presents a barrier to wildlife movement.
