This week, the Capital Regional District warned that Greater Victoria’s water supply is highly vulnerable to the threat of wildfires, should those fires occur in the Sooke and Goldstream watersheds.
Recent warm, dry conditions have led to increased fire activity in northern British Columbia, and the B.C. Wildfire Service has issued a high-danger rating for Southern Vancouver Island, including the Sooke and Goldstream watersheds. Both these watersheds feed into Greater Victoria’s drinking water reservoirs, where there is no filtration system.
Although wildfires are a natural form of disturbance that are important to forest health, massive wildfires such as those seen in Fort McMurray, can can adversely affect water supply and water quality for downstream water treatment plants, rendering them inoperable. These impacts can last for years or even decades, as fluctuations in erosion of ash and debris may continue to enter waterways following heavy rainfall events, causing major challenge for drinking water treatment.
Ted Robbins, general manager of integrated water services for the Capital Regional District (CRD) told the Times Colonist that the CRD manages all the activities in these watersheds in order to maintain such high raw water quality, therefore filtration is not normally necessary. He said that installing filtration would cost in the tens of millions of dollars.
The CRD will soon be conducting aerial patrols to enable early detection of forest fires, and has undertaken longer-term studies to assess the potential impacts of climate change, including projections of more wildfires.
In 2014, the Canadian Water Network conveyed a group of experts to assess the state of knowledge on the risks posed by wildfires to drinking water supplies and the methods available to mitigate them. The experts stated that, in certain regions, historical fire suppression has led to a buildup of fuel that can make future wildfires more extensive and severe. Forest management and water treatment strategies that can reduce wildfire risks to water supply and treatment exist.