BC Hydro reduced the Puntledge River flow by about 11 per cent on Dec. 9 in its ongoing response to the record dry fall conditions within the watershed. The Comox Lake Reservoir is around the bottom operating range and the water inflows into the reservoir remain low. Hydro’s focus is to maintain water flows downstream for fish habitat and to keep salmon eggs covered with water.
Water storage is very low on the Puntledge system and other Vancouver Island hydroelectric watersheds, though we are fortunate to have an integrated provincial system and the supply of power is not an issue with our large hydroelectric systems in the interior. The Puntledge River powerhouse is not operating given the low water levels.
“This fall, since Sept. 23, the upper Puntledge watershed has had the lowest precipitation in 41 years,” said BC Hydro spokesman Stephen Watson, in a press release. “There’s been 278 mm of precipitation. The average over this time period is 746 mm. That’s a deficit of 460 mm or about 46 cm of water. We’ve received only about 37 per cent of normal precipitation. For water inflows in the reservoir, this has also set a new fall season 60-year record with inflows coming in at about 26 per cent of normal. By comparison, over the same period in 2021, there was 1,041 mm of precipitation in the upper watershed.”
Water inflows into the Campbell River system are only about six cubic metres per second (m3/s) this week.
The snowpack is about 50 per cent of normal for this time of year though lots of time to recover. The snowpack typically peaks in April.
The Comox Lake Reservoir operating range is between 131 metres above sea level to 135.3 metres. The level has been hovering at 131 metres, and is currently at 131.03 metres. The Comox Dam is about 300 metres downstream from the lake outlet.
The minimum fish habitat flow below the Puntledge powerhouse is 15.6 m3/s.
“On Friday (Dec. 9), we reduced the river flow from nine m3/s to eight m3/s,” said Watson. “Fish salvage crews were on the river at key areas to move small fish that may get isolated back into the main river flow and to monitor water depth at fish spawning areas called redds. Our goal is to have salmon eggs remain covered with water. The Puntledge riverbed above the powerhouse, which has a lower minimum fish habitat flow, will have more typical water coverage and keep the salmon eggs covered with water.”
The reservoir level and the Puntledge River flow are both at record lows for this time of year.
BC Hydro will continue to focus our operations on environmental efforts until some significant storms may hit the watershed. The next two weeks look to be dry and cool, thereby extending the very dry conditions and the need for last weeks’ reduction of downstream river flows.