B.C. is known for its rainy weather, so it may be surprising to suggest that serious droughts might occur here.
California has been fighting drought, with partial success, for a number of years. It has only been able to do so because the bedrock there consists of thousands of feet of clastics, many of which are porous. Some contain oil and gas, but the majority hold, or held, huge amounts of fresh water which percolated in, over time. Unfortunately, this supply is presently running out.
Here in B.C. the bedrock is igneous and metamorphic rocks, with a limited amount of older, indurated sediments. None of these make effective water storage reservoirs.
The most recent geological event in B.C. was the ice age, which scoured the bedrock clean. Since then alluvial beds have developed in valleys and low-lying areas, and most hold water. For example the Fraser delta will have aquifers. Qualicum Beach has some, in either glacial or old seashore sands, but the volume is limited.
The mini-drought which occurred this past summer indicates what a major one could be like. The size of the catchment area would determine the rate of drop in the flow. For example, on the Little Qualicum River at the flats near the access road, where the water is usually about a foot deep, the level dropped rapidly and stayed at a couple of inches. By that point, the adjacent aquifers had taken over. Had these dried up the river bed also would have become dry.
This makes it clear that a serious drought lasting, say, a year or more, could have a major effect on the province. The ideal scenario for B.C. would be to have heavy snowfall in winter to provide water in the summer. The next best would be rainfall all year.
The significant weather changes taking place today are probably due to human activities, but they have no quick solution. Here in B.C. we can only hope for the best. The saying “man proposes, God disposes” might be appropriate.
Jim DrummondQualicum Beach
