At this time of year, BC’s rivers are running at full throttle. Spring runoff fuels their flow. Power production from rivers is at peak levels, too, as I saw when I visited Innergex’s Ashlu Creek Hydro Project north of Squamish last week.
After hours spent hammering out Shared Principles for a low carbon economy, with Energy Forum partners like Innergex, it was great to see one of their projects in operation.
Run of river is a fast-growing industry in B.C. Its’ obvious climate change benefits must be balanced with the impacts of taming rivers.
A bit of background: the Ashlu project was built off an existing forestry road on a prime whitewater kayaking river containing trout and salmon. Residents were incensed that the local government‘s refusal to rezone the property was overturned by a hastily passed provincial law. A fish kill incident after the project was built in 2010 didn’t help. Most recently, the company was criticized in a Department of Oceans and Fisheries (DFO) audit Review of Habitat Monitoring at Twenty-Two Independent Power Projects though Innergex says it follows monitoring practice Long Term Aquatic Monitoring Protocols for New and Upgraded Hydroelectric Projects required by the DFO.
Altering water flows is the main concern with these projects. As DFO’s important new science advice report states, “The scientific literature supports natural flow regimes as essential to sustaining the health of riverine ecosystems and the fisheries dependent on them.” And these systems are “placed at increasing risk with increasing alteration of natural flow regimes.”
So we asked many questions about how the Ashlu Creek project alters the natural river flow. The company takes flow maintenance seriously, and has taken several steps to improve social and environmental licence. The project starts at a constructed headpond, smaller than a traditional dam’s large reservoir. It diverts water through a 4 km-long tunnel drilled through the mountain rock, and empties the water at three turbines in the powerhouse. Due to run-off, the instream flow rate of 60 m³/s was higher than the 2.42 m³/s rate that the company is required to maintain year round.
These unique project features deserve note:
- A fish ladder at the intake site is covered to keep the fish from “committing suicide” by jumping off the ladder and to protect the fish from marauding birds. About 1,000 rainbow trout are tagged to monitor their health. According to Innergex, so far Ashlu Creek maintains the same amount of fish that were in the creek before the dam was constructed.
- An Energy Dissipation System acts as a giant shock absorber for the huge volumes of water flowing through the intake to the turbines. This system, now marketed around the world, allows a controlled and progressive change of water flow in the stream, beneficial for kayakers as well as fish.
- Innergex constructed over 50,000 square metres of ponds and channels of new fish habitat to help compensate for habitat lost or damaged during project construction and operation. We walked around ponds and channels named Spirit, Black Bear, Toad and Crow’s Nest that support pink and coho salmon, rainbow trout and another forty wildlife species.
- The company maintained kayak access for local paddlers and came up with innovative ways to accommodate them, such as scheduled recreational days where specified flows are released and the company’s web site for recreational users.
The climate benefits are clear too. The facility supplies enough electricity for 24,000 homes each year. By comparison, the company calculates that an equivalent-sized, coal-fired power plant releases approximately 219,000 tons of carbon dioxide gas. By contrast, the Ashlu Creek project operates with zero emissions. ( However, construction, maintenance and decommissioning of the plant all involve emissions)
Run-of-river hydro was ranked as the least environmentally disruptive technology available in an Ontario Power Authority study of fourteen electrical generation methods though problems still remain with an industry chided for multiple water use violations that to date carry no repercussions according to a provincial audit. Progress is slow, as well, on measuring cumulative impacts of multiple run of river projects, though researchers are working to fill this gap.
This clean energy source stands out as a solution in our carbon constrained world. Thanks for the tour, Innergex!