Two major rivers on Vancouver Island have reached historic lows for water flow, but BC Hydro says power supply is not an issue.
The Puntledge River flow and the Comox Lake Reservoir level have never been as low as they are now heading into December, and the Campbell River reservoir storage is the lowest on record since 1984, BC Hydro said in a news release Monday.
The Campbell River flow release will also be the lowest it’s been since 1983, the company said.
BC Hydro says the company was hoping for good storm systems to get things back to normal in the Puntledge River, but the forecast looks dry and cold into next week.
The Puntledge River flow rate will be reduced to nine cubic metres per second from the current rate of 11.m3/s. Fish salvage crews were on site as the flow was reduced at key parts of the river.
“Anything lower than this level will begin to expose salmon eggs in the gravel,” the release says. “The one positive about having the river flows so low this fall is that salmon, like chum, which typically spawn after October 1, have spawned in areas near the middle of the river versus the entire riverbed so with our latest river flow reduction, those eggs should remain wetted.”
The water flow should be fine for fish habitat from the Comox Dam to the powerhouse, but from the powerhouse and down the water flow has a potential impact to fish habitat and the fish hatchery, which has a minimum fish habitat flow of 15.6 m3/s.
The Comox Lake Reservoir is currently at at 130.98 metres, which is below the minimum operating level of 131 metres where it is considered full at 135.3 metres.
“With the unprecedented delay in the fall rains, the reservoir level has hovered around 131 metres and is forecasted to decline with the upcoming cold weather,” the release says.
Snowpack in the upper watershed is less than 25 per cent of what is considered normal for this time of year, though BC Hydro notes main snow accumulation generally occurs in December through March.
The Campbell River system is in a similar position.
BC Hydro is planning to reduce flow on Tuesday from 65 m3/s to 55 m3/s, which should not impact salmon eggs in the gravel.
“The forecasted water inflows into the watershed for this week are around 25 m3/s,” a release says. “We continue to lose available water storage. The Upper Campbell Reservoir/Buttle Lake is currently at 213.4 metres above sea level and slowly rising as we rebalance the reservoirs.”
The minimum reservoir level is at 212 metres.
BC Hydro says there is little flow moving below the Strathcona Dam, but downstream Campbell River flow requirements are being met from the Lower Campbell River reservoir.
READ MORE FROM OCTOBER: Fish salvage crews on scene at Puntledge River as flow reduced: BC Hydro
Laura Brougham
