We’re learning more about what was likely behind a mass fish die-off in the Cowichan River last summer, as the waterway faces potentially another dry summer in light of low snowpacks.
The province says tens of thousands of juvenile rainbow trout were likely killed in the event in 2023.
“We are seeing a wildly overproliferation of nutrients at the outfall of the Lake Cowichan sewage outfall. We know that affects the river in a number of ways,” said Lydia Hwitsum, the Cowichan Watershed Board co-chair and Cowichan Tribes Chief.
The province says at the time, water temperature and increased nutrients led to an increase in algae growth, which degraded water quality. With PH and oxygen levels outside of the tolerable range for fish, they died.
Fisheries and Oceans Canada says low flows and hot, dry weather were also factors, which is concerning considering how low the snowpacks are this February.
B.C. government data shows Vancouver Island’s snowpack is just 30 per cent of normal right now.
“The low snowpacks are clearly a concern and we need to monitor them because we count on them to feed the water system,” said Hwitsum.
Hwitsum says the nation has been helping work towards a critical solution of raising the Lake Cowichan weir – a project that’s been in the works for years.
“We’ve got some funding from the federal government. We’re working to leverage a final piece of funding from the provincial government and that funding will go towards raising the weir, so replacing the weir and being able to hold back up to 70 centimetres more of water so that we can feed the river at critical times.”
Fishing guide Alex West loves when his customers catch fish on the the Cowichan River, but fishing opportunities have been becoming more scarce with environmental changes and dwindling fish populations.
“After the last few years it’s scary, really. Every year it’s getting worse and worse. Our rivers, our fish, they’re taking a beating,” said West.
West says he wants the Cowichan River to thrive and he hopes there is a silver lining from last year’s die-off, a speeding up of the projects that will aid the river’s health.
“Hopefully this is what it takes in order for the government to step in there and make some changes for the better effluent going into the river,” said West.
Another move in the right direction was when federal funding was announced this past fall for a project to better treat the Town of Lake Cowichan’s wastewater before it enters the river.
It’s hoped provincial funding to raise the weir might be coming this year.
Kendall Hanson
