It’s that time of year when BC Hydro bumps up the seasonal fish passage flows down Elk Falls Canyon.
BC Hydro will provide nine, 48-hour pulse flows down the canyon on the Campbell River system to benefit migrating salmon. Elk Falls is a natural barrier to fish passage, though there is good habitat between the new powerhouse tunnel outlet and the falls.
This year the first migration flow will happen today and tomorrow (Sept. 18 and 19), and continue to occur on those same days of the week for eight more weeks ending Nov. 14.
Flow in the canyon will increase from about 4 m3/s to about 7 m3/s during each migrating flow. BC Hydro is advising the public to stay away from the upstream side of Elk Falls when the migrations flows are in place. Temporary safety signage will also be in place. During some of the pulses, BC Hydro may reduce the flows out of the John Hart generating station by 3 m3/s should watershed conditions continue to be dry.
Meanwhile, the water levels conditions in the Campbell River system remain low. As the company has communicated all year, the late winter, spring and summer inflows have been below normal and the snowpack was also depleted earlier than normal.
Records have been set at various times in 2019 for low precipitation and water inflows. Inflows into the system have been below 20 m3/s for the last month while BC Hydro has been releasing about 30 m3/s downstream into the lower Campbell River for fish habitat, about the lowest level permitted by the utility’s water licence. Inflows are expected to go up slightly with the modest rain we’ve had lately and then potentially drop down again.
The combined water supply observations and forecast for the February to end of September period continues to track as the lowest water supply year in BC Hydro’s 57-year period of record.
Moving upstream, the water level in Upper Campbell Reservoir/Butte Lake is currently at about 216.25 metres. The dry conditions resulted in this reservoir not reaching the preferred range for the summer recreation period, which is between 217 and 220.5 metres.
“We were able to manage it between 216.3 and 216.9 metres, which was a bit better than expected given a wetter July and a good rain event on Aug. 1,” BC Hydro spokesperson Stephen Watson said.
The Lower Campbell Reservoir/McIvor Lake is currently at about 176.15 metres and has fluctuated between 175.9 and 176.5 metres during the summer recreation period. This reservoir also did not enter into the preferred summer recreation level of 176.5 metres to 177.5 metres.
Now moving through September and into October, reservoir levels will move into the preferred operating range in the next few days as Hydro’s water use plan allows lower water levels to prepare for the fall rains and potential flood risk management operations. The Campbell River reservoirs are expected to refill with the fall and winter storms.
We have held the Campbell River flow at 30 m3/s since late June. We will begin to increase flows below the John Hart facility to allow for salmon migration within the Campbell River and to lower the water levels in the reservoirs in anticipation of the fall rains.
The Campbell River flow will increase to 50 m3/s in the early morning of Sept. 25, and then to about 80 m3/s in the early morning of Sept. 27. A flow rate of about 80 m3/s keeps the riverbed covered with water and will assist in Chinook salmon spawning.
People fishing for salmon in the river, with waders, should be aware of the increasing flow rate and the substantial change in river flow hydraulics and demonstrate appropriate caution.