With the recent wet conditions in the area, all of the 20 pumps that Catalyst Crofton was using since Sept. 15 to pump water over the weir at Cowichan Lake to sustain water levels in the Cowichan River have been shut down.
Brian Houle, Catalyst Crofton’s environment manager, said Cowichan Lake is now half full due to rain and the river has returned to gravity-feed from the lake.
“This was very helpful as we had reports of fish wanting to get into the lake and [being] held up due to the operation of the pumps and confused with water moving in the wrong direction at the fish ladder,” he said
“Then on [Oct. 19], as lake levels continued to rise, the weir was taken off control, with all four control gates lowered to the river bottom and 100 per cent open. In this condition, fish are free to navigate through the gate structure and through the fish ladder given water was flowing from lake to river.”
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The severe drought that struck the region during the summer lowered water levels in the Cowichan River dramatically, so Catalyst began using the pumps last month to pump water over the weir at Cowichan Lake to sustain water levels in the river with a base flow of 4.5 cubic metres per second.
The Cowichan basin has experienced 14 droughts since 1998.
A winter with below average snowpack followed by a drought beginning in mid-May were the root cause of this year’s conditions.
Houle said that while Cowichan Lake is now 50 per cent full, the recent dry weather has allowed the lake’s water levels to begin to decline again.
“I won’t even share a weather forecast this week as it does not matter what next week brings,” he said.
“Rain will continue now that we are in the wet season and the lake level is high enough to sustain the river for many weeks.”
Houle said the pumps and scaffolding at the weir will be removed from the area this week, and the weir will be winterized and shut down after the pumps are removed.
He said the exact timing of when the weir will be shut down has yet to be determined.
“The fish counting fence was removed from the lower river in advance of the rising water levels,” Houle said.