Water inflows into the Comox Lake Reservoir have been low since early February, said BC Hydro in a water forecast Thursday.
After a very wet January, the weather since then has been quite dry. The amount of precipitation for February was 48 per cent, 31 per cent in March and 14 per cent in April to date – 14 per cent of normal. This is the fourth consecutive year where the February to March period has had well below normal precipitation.
The Vancouver Island snowpack is about 80 per cent of normal for this time year. The snowpack typically peaks around the end of April, noted Stephen Watson, stakeholder engagement advisor for BC Hydro in a statement.
“Our February to September water supply forecast is updated each month. This forecast guides our Puntledge River operations and water management for various water use interests such as fish habitat, domestic water supply, recreation and power generation,” he noted.
As of early April, the water supply forecast for the February to September period is showing 78 per cent of normal. To compare, the February forecast was showing 103 per cent of normal but the dry weather since then has meant a reduction. The residual forecast for water inflow from April to September is 81 per cent of normal, with that slight difference being the anticipated snowmelt.
The Comox Lake Reservoir is currently at 132.35 metres, which is about 1.25 of a metre below the normal level for this time of the year. The reservoir has been slowly moving down over the past few months. Generally, the reservoir level fluctuates between 131 metres to 135.3 metres.
The 24 megawatt (MW) Puntledge River Generating Station has just been reduced from about 10 MW to about 7 MW, or about 30 per cent of capacity.
BC Hydro, in following a February to April model that was developed in collaboration with DFO and the Ministry of Forests, Lands and Natural Resource Operations, continues to operate the generating station and fish screen within the penstock so that the salmon fry out-migration meets or exceeds the 95 per cent successful fish passage target below the Puntledge River Diversion Dam.
This dam is about 3.7 km downstream of the Comox Dam.
BC Hydro is releasing about 16 cubic metres per second (m3/s) from the Comox Dam, which is slightly above the downstream Puntledge River minimum fish habitat slow of 15.7 m3/s.
Watson said the water flow release may generally continue until we typically see the freshet in May.
The Puntledge River flows this spring and summer will be dependent on snowmelt and rain events. BC Hydro will provide an operational update in early May.