After being extremely low in the late summer and high once the rainy season began, the level of Comox Lake is once again low, BC Hydro said Thursday in a news release.
"Some of you have heard about the low water conditions on the Campbell River system and a very similar situation is taking place on this watershed," began BC Hydro spokesman Stephen Watson.
The water inflow conditions into the Comox Lake reservoir have been below normal since August, he noted. The one exception is the significant storm at the end of November and beginning of December, though much of that water was released downstream for flood risk management.
The weather conditions have been relatively dry and cool. What precipitation has fallen has been as snow in the upper watershed, Watson continued.
The lower temperatures are also not allowing for much snowmelt. Water inflows for the last three weeks of December were 40 per cent of normal, and so far for January, 33 per cent of normal.
"BC Hydro is always monitoring reservoir conditions and weather forecasts. In managing through this low water abundance condition, BC Hydro has reduced the downstream flows and the power generation output."
BC Hydro reduced the generation station to about 80 per cent of capacity through much of November and December, and has been operating the generating station at 37 per cent of capacity since Jan. 1.
A minimum fish habitat flow of 16 cubic metres per seconds (m3/s) is in place below the generating station. This is the river flow threshold that allows fish habitat to be covered with water.
The Puntledge River flow has been around 18 m3/s since Jan. 1 but Hydro we reduced the river flow Thursday to the minimum 16 m3/s level.
BC Hydro may consider reducing river flows down further at the end of the month should the weather pattern continue, Watson said. BC Hydro is discussing the situation with Fisheries and Oceans Canada. Water inflows into the reservoir are forecast at only 9 m3/s.
The weather forecast calls for continued dry and cool conditions through the end of next week. February and March tend to be lower water inflow months due to cooler temperatures and fewer storms.
November through January is BC Hydro’s flood risk management period on Vancouver Island and one large storm event can change things dramatically, watson explained. No such storm hit the area in December and it appears that will be the case for January, he added.
The Comox Lake Reservoir was at 132.2 metres Thursday and is dropping three to four centimetres per day. The reservoir is considered full at 135.3 metres and conditions can get critical at around 131 metres for providing suitable flows downstream.
The reservoir, which is the source of public water for most of the Comox Valley, is at the fifth-lowest level for this time of year based on 50 years of record. The upper Campbell reservoir/Buttle Lake on the Campbell River system is at the fourth-lowest on record for the time of year.
BC Hydro said it will provide further updates as conditions develop.