Cooler and drier weather hit the Campbell River area just in time to prevent the Upper Campbell reservoir from running out of room for water storage.
That change in weather around Dec. 30 combined with the lack of an ocean storm surge in the same period diminished the risk of flooding from the Campbell and Quinsam rivers, BC Hydro spokesperson Stephen Watson said.
“The fortunate aspect of the week was there was little ocean storm surge from winds,” Watson said in a Jan. 3 update. “It is also fortunate the weather turned drier and cooler on Saturday given we were running out of available water storage room within the reservoir to hold back water at key times.”
Watson was updating the community on the storm activity last week and provided notice of a public safety advisory extension to stay away from the water flows within Elk Falls Canyon and the Campbell River through to Jan. 5.
The water inflows from the successive storms last week were significant, Watson said, with about 300 mm of precipitation falling in the upper Campbell River watershed from Dec. 25 through Dec. 30. The storms were focused on Central Vancouver Island. It was also a warm week that led to significant snowmelt from Dec. 28 to 30, and the snowpack remains well below normal for this time of year.
A nice silver lining from all that storm activity last week for the #CampbellRiver system is more clean power generation. ⚡️ pic.twitter.com/Tq8VQiOjAe
— Stephen Watson, BC Hydro (@SWatson_BCH) January 3, 2024
The month of December finished off at 154 per cent of normal precipitation, with water inflows into the Campbell River system for the month being 176 per cent of normal – the third highest in 61 years of record.
Water inflows into the reservoir from Dec. 25 to 30 were high, reaching a peak hourly inflow rate of 920 cubic metres per second (m3/s). The discharges below the John Hart facilities were moved down and up for a number of days last week as BC Hydro responded to high ocean tides.
Discharges from the facilities ranged from as low as 80 m3/s for three hours at high tide, to as high as 230 m3/s. The flow rate of about 185 m3/s from the John Hart facilities was increased to 230 m3/s on Dec. 28. The current water release is 230 m3/s and will be reduced to 165 m3/s by early Thursday, Jan. 4 morning. The water release down Elk Falls Canyon will then be reduced to the base flow of 4 m3/s by Saturday morning. The public is advised to view Elk Falls from the safety of the suspension bridge.
The Quinsam River, that flows into the Campbell River below the John Hart facilities, was also flowing high last week and hit a peak of 75 m3/s.
The Upper Campbell Reservoir/Buttle Lake level increased by about two metres and hit a peak of 220.05 metres on Dec. 31. The reservoir storage is considered full at 220.5 metres. The water inflows over the weekend dropped off significantly and with the continued high water release downstream, the reservoir level is slowly dropping and is 219.85 metres.
“We closely monitored the downstream Quinsam River flows and high tide and operated within those considerations for flood risk management,” Watson said.
Throughout the storm activity there was close communication with the City of Campbell River and the Strathcona Regional District.
READ MORE: Expect flows from the John Hart powerhouse to fluctuate over next few weeks