Snow pillow, doesn’t sound like a comfortable place for your head to get a good night’s sleep. If you are concerned about water though, a favourable snow pillow reading might help you to rest a little easier.
A snow pillow instrument consists of a three metre bladder containing antifreeze. As snow accumulates on the pillow over the winter, the weight of the snow pushes an equal weight of antifreeze up a tube. The water content of the snow or the Snow Water Equivalent ‘SWE’ is measured each hour and the data is automatically transmitted to the Water Stewardship Division of BC’s Ministry of Environment.
By the end of April, higher elevations have received close to 100 percent of the total winter snowpack. In some springs we have above normal SWE readings and there is more chance of flooding, especially if an early season hot spell melts the snow at a faster rate. In other years, when measurements are below average, there is concern about having enough water to last through the summer months. It doesn’t seem to happen that often that we have an average amount.
So what does this all mean for the Shuswap you might ask? The closest snow pillow readings are taken at the 1500 metre level on Celista Mountain, north of Shuswap Lake. This year the SWE numbers in early May are approximately 80 percent of normal. Therefore, as the snowpack starts to melt, the flooding danger appears to be minimal this spring. There is however, the potential that we will see lesser amounts of water available for domestic, farm and industrial usage by this summer.
The weather over the next couple of months will determine if there are going to be any water shortages. April was drier than normal but currently, in the early part of May, rainfall has been above average. The ‘cold low’ season that can bring considerable amounts of rain, seems to have arrived a bit earlier than usual.
Cold lows or upper low pressure centres, typically migrate from the Gulf of Alaska through southern and central BC in June. Usually by the first week of July, high pressure ridges take over and the warmer and drier days of summer begin.
It is impossible to say at this point what the rainfall amounts will be in the next few months. Environment Canada’s forecast for May to July calls for near normal precipitation. However the track record of this product is under 40 percent accuracy, not exactly inspiring too much confidence.
Whatever comes our way, it is still a good idea to conserve as much water as possible just in case this turns out to be a dry year. Using mulch in gardens and cultivating drought-resistant native plants can save a lot of water. Xeriscaping can reduce or even eliminate supplemental irrigation. BC Hydro has a lot of great tips on how to save water. Google ‘BC Hydro – Save Water Outdoors’ to go to the website.
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