Water flows over Elk Falls will increase 12-fold in August as BC Hydro diverts water from its John Hart hydroelectric facility’s underground tunnel
However, downstream flows in the Campbell River will remain unchanged, BC Hydro says.
In addition, there will be three days of Brewster Lake Road closures across the John Hart Dam.
The water is being diverted so BC Hydro can conducted planned John Hart facility tunnel inspections and maintenance work.
“Every four years we dewater and inspect the approximate 2.1 kilometres of underground tunnels that lead from the John Hart Dam down to the powerhouse, and from the powerhouse to the tunnel outlet at the river,” BC Hydro spokesperson Stephen Watson says. “This will be the first time for this maintenance cycle since the new replacement facility went into operation in October 2018. During this time there will also be annual generator and related equipment maintenance. The work is timed to coincide with low water conditions in the summer.”
To allow for the inspections, the water flow down the tunnel will be redirected through the spillway gates at the dam down Elk Falls Canyon to maintain the downstream river flow. The four cubic metre per second (m3/s) canyon base flow will increase to about 50 m3/s on the evening of Aug. 6. The flow transfer back to the tunnel is planned for Aug. 24. BC Hydro is issuing a public safety notice to stay away from Elk Falls and the canyon water flow from Aug. 7 to 24. Temporary safety signage will be in place around Elk Falls. People will be able to view the falls from the safety of the Elk Falls suspension bridge.
The lower Campbell River is currently flowing at about 50 to 54 m3/s and it will stay at that level through August 6.
Part of the inspection process and maintenance work is to install and remove metal stop logs to prevent water from entering the water intake to the tunnels under the John Hart Dam. Cranes will be required and to safely complete the work, Brewster Lake Road across the dam is scheduled to be closed on Aug. 9, 12 and 19, from around 8 a.m. to 5 p.m. There is a chance the work schedule could shift so check on the site road closure signage.
People walking the Canyon View Trail near the tunnel outlet may see intermittent, short duration closures around Aug. 8 to 12 to move in cranes and equipment to allow for the dewatering on the tunnel that goes from the underground powerhouse to the river.