The weir at Cowichan Lake resume operations for the 2020 season March 18.
The weir regulates the flow of water from the lake to the river in order to sustain a minimum flow in the river through the entire dry season.
The first action will be to lower the two boat lock gates. As soon as two days after the boat lock gates are lowered, the control gates on the south side of the weir can begin to operate and reduce the flow in the Cowichan River and down to the seasonal requirement of 25 cubic meters per second. An early start-up of the weir was planned this year due to a below average snow pack, low lake level and dry weather.
The Cowichan boat lock, which prevents water from leaving the lake while allowing boats to travel from lake and river began operations on March 18. Guidance on the use of the boat lock is provided through signage at entrance to the boat lock both from the river side and the lake side. An operator is stationed at the boat lock throughout the dry season to ensure boaters can navigate through to the lake or river.
Catalyst Crofton, owned by Paper Excellence Canada, operates the weir as authorized in the water license and through guidance from the Operational Rule Curve (2013). It is the license and the rule curve that stipulates the flow and if needed (dry summers), the water manager can authorize lower flows.
In addition, the fish stewarding agencies, including both provincial and federal fisheries agencies, Cowichan Tribes and Cowichan Watershed Board, all provide input into ideal spring flows that help sustain fish populations that either begin their life or live their life in the Cowichan River.
In the event that spring rainfall and snowmelt cause the lake level to rise to above full supply, the spill gates will be adjusted to release more water and control the lake level to full supply but not over full. Monitoring and regulation of Cowichan Lake and River water levels is part of the Ministry of Forests, Lands, Natural Resource Operations and Rural Development’s ongoing commitment to maintain stream flows for fish, First Nations, water license holders and recreational water users.