Quamichan Lake Remediation Project

North Cowichan is trialing remediation methods to address the water quality conditions in Quamichan Lake. The trials will occur during the spring and summer of 2026

TRIAL 1:

Timeframe: April to June 2026.

Purpose: This trial will assess the effectiveness of oxygenating the bottom of the lake to reduce internal loading.

Description: The first enclosure will contain a small-scale aerator at the lakebed and diffused air mixing system in the top layer of the lake to increase the size of the top layer of the water column and oxygenate the bottom layer of water. The paired systems are expected to reduce the aerator’s required operational time as the bottom layer of the lake should be decreased in size. The second enclosure will only include a small-scale aerator to oxygenate the bottom layer without affecting the natural thermal structure of the water column. The third enclosure will not contain any aeration and will act as the control. Ambient lake conditions will also be sampled to compare to the control to evaluate any potential effects the enclosures themselves may have on the results.

TRIAL 2:

Timeframe: June to August 2026.

Purpose: This trial will assess how nutrient binders magnify the effect of aeration to reduce phosphorus in the water column to mitigate cyanobacteria blooms.

Description: The first enclosure will contain a small-scale aerator and diffused air mixing system with an aluminum-based binder. The second enclosure will contain a small-scale aerator with an iron-based nutrient binder. The third enclosure will not contain any interventions and will act as the control. The ambient lake will also be sampled to compare to the control to evaluate any potential effects the enclosures have on the results.

For more detailed information about this project, please visit the MNC Website at this link: Quamichan Lake Trials