With water levels dropping dramatically in Cowichan Lake and Cowichan River this summer, the Town of Lake Cowichan has dropped its treated wastewater effluent inputs to the river by half, with releases now happening overnight in an attempt to reduce algae growth.
The latest data is showing conditions in Cowichan River are similar to those of 2023, with rising temperatures and significant daily fluctuations in pH and dissolved oxygen levels.
Combined, these factors can be lethal to fish and other aquatic life.
In 2023, more than 84,000 fish died in the river due to low summer river flows, warming water temperatures, and declining water quality.
The annual closure of the fishery on Cowichan River, which usually runs from July 15 to Aug. 31, started on July 4 this year to protect fish populations as conditions in the river worsen.
Cowichan Tribes Chief Cindy Daniels (Sulsulxumaat), who is co-chair of the Cowichan Watershed Board, said the First Nation’s lands and natural resources staff have been closely monitoring conditions on the river and, over many weeks, have contributed valuable knowledge and advocacy for the recent decision to close the fishery early.
“We take our guardianship responsibilities seriously to protect the river, the fish, and other species that depend on it,” she said.
Cowichan Valley Regional District Chair Kate Segall, who is the other co-chair of the CWB, added that the CVRD is committed to maintaining healthy watersheds and aquifers across the region.
“The effects of climate change are being felt in the Cowichan as summer droughts are affecting the health of our environment and our communities,” she said.
“The CVRD supports the efforts to raise the Cowichan Lake weir to increase our resilience to climate change.”
The Cowichan River is currently being monitored by a system that has been called the best in the country, according to a press release from the watershed board, with data being collected continuously at six different locations.
“A highly skilled coalition of experts, including Fisheries and Oceans Canada, BC Ministry of Water, Land and Resource Stewardship, Cowichan Tribes, CVRD, BC Ministry of Environment, the Town of Lake Cowichan, CWB, local knowledge holders, and special advisor, Dr. Ken Ashley, an internationally recognized fish and water quality scientist, is meeting regularly to review the data and respond to emerging conditions with the best tools available,” the release said.
“This information is supplemented by river flow data provided through a Water Survey of Canada partnership with Domtar, the current owner and operator of the Cowichan Lake weir.”
Field research is currently underway to identify, protect and improve “cold water refugia” areas, in the river which are extremely important to fish during warm water conditions.
But authorities acknowledge that while every available action is being utilized to deal with the worsening conditions, without rain or cooler temperatures in the near future, it may not be enough to prevent another major fish kill this summer.
“This is an all-hands-on-deck moment for the Quw’utsun Sta’lo’ (Cowichan River) and other rivers in our region,” said Danielle Paydli, executive director of the CWB.
"Every action, no matter how small, helps protect the rivers and life that depend on them."
The CWB is encouraging the public to report distressed fish in the river to DFO’s 24/7 hotline 1-800-465-4336 or DFO.ORR-ONS.MPO@dfo-mpo.gc.ca, and report pollution in the river to B.C.’s RAPP line at 1-877-952-7277 or forms.gov.bc.ca/environment/rapp.
The CWB also encourages people to conserve water this summer and avoid swimming in the river during low flows to avoid damaging fragile habitats.
