North Cowichan staff have begun the installation of scientific test equipment in Quamichan Lake to assess potential solutions to ongoing cyanobacteria blooms. Quamichan Lake, which is shallow, has experienced many decades of algae blooms, particularly in the summer due to warm, oxygen deprived water and elevated levels of phosphorus. The poor water quality also contributes to fish kills.
Once installation is complete, the trial will run from May to August. Three, eight metre diameter, cylindrical enclosures will be fixed to the lake bed and will extend to just above the lake surface. The first set of trials will measure the effectiveness of using aerators. The second set of trials will test the effectiveness of adding nutrient binders to augment phosphorus removal from the water column. In the trials, two of the enclosures will use different combinations of aerators and metal additions, while the third enclosure will not have any interventions and serve as a reference to contrast changes to see what effects the enclosures themselves have on the water quality.
Following the trial period, the enclosures will be removed, and staff will analyze results to determine the effectiveness of the different treatments. Results will be shared with provincial regulators, Council, and the community to seek direction on a possible lake-wide system. Successful treatment options could also be applied to other parts of the watershed including Somenos Lake and marsh, which also experience regular algae blooms.
The $200,000 trial is funded through the Cowichan Valley Regional District’s Drinking Water and Watershed Protection Program.
Kwa'mutsun Xatsa (Quamichan Lake) is deeply connected to the Quw’utsun Peoples, who have long lived on its shores and fished its waters. Beginning in the 1860s with European settlement, land clearing, and agricultural development significantly altered the landscape and the lake chemistry.
North Cowichan is proud to be the home of Rowing Canada Aviron (RCA). In 2019, RCA moved its national training site to Quamichan Lake and has since hosted national and international meets as well as qualifying regattas for national and Olympic team events. North Cowichan has committed to improving the water and surrounding environment of Quamichan and Somenos Lakes.
Visit connectnorthcowichan.ca/quamichan-lake to learn more about the Quamichan Lake trials and next steps.