Recent rain helped, but Comox Lake still lower than normal
The past month, and this past weekend, have provided a well-needed break from the dry weather conditions since October, BC Hydro reported Tuesday.
While this has helped marginally for near-term operations, the wider concern for water abundance for the spring and summer hasn’t changed that much.
The February water inflows into Comox Lake Reservoir were 37 per cent of normal. However, there was a normal amount of precipitation for the month and it mostly fell as snow to improve the snowpack.
The daily water inflows from last Saturday’s storm were the highest in the Comox Valley in five months, but there were not as high as forecast due to less-than-forecast precipitation and greater-than-forecast snow accumulation.
Water inflows into Comox Lake reached about 89 cubic metres per second (m3/s). The next two week or so looks to be relatively dry with light precipitation likely this weekend. Water inflows are looking to be around 25 to 30 m3/s by the end of the week.
The Comox Lake reservoir has hovered near the 132- to 132.4-metre range for months. There’s been little fluctuation. It has risen nicely from the Saturday storm and is at 133.1 metres and slowly rising. 135.3 metres is considered full.
BC Hydro has been operating the 24-megawatt generating station at 20 to 40 per cent of capacity since October to conserve water for downstream fish habitat. The current output is 18 MW (release of about 23 m3/s from the dam) or about 75 per cent of capacity.
BC Hydro sees this decreasing over the next few weeks back down to 10 MW or possibly 5 MW depending on inflows.
The Snow Survey and Water Supply Bulletin for March was issued by the Province, and for the Vancouver Island region, the snowpack is now 52 per cent of normal — up from only 28 per cent of normal last month. There’s still time for snow accumulation.
BC Hydro’s updated February to September water supply forecast, now into March, shows water inflows into the Comox Lake reservoir are forecast to be about 75 per cent of normal. This forecast considers snowpack, precipitation, and historical water inflows from the past 50 years.
Should the weather be dry or wet, the water inflow variance can be +/- 18 per cent.
We still need much more wet weather over the next few months to recover, and even then, it may not get to average conditions.
BC Hydro will provide an operational update around mid-April.
— BC Hydro