A group effort is helping to clean up Quamichan Lake while offering a refuge for trout.
And the success is bubbling up as the aeration plan is working to re-vivify the lake bottom at the Woodmere end of the lake.
Everyone involved with the project showed their delight with a special celebration recently as the Quamichan Stewards opened the trout refuge.
It started operation just this fall and is already proving its effectiveness, according to Jim Cosh of the Stewards.
The trout refuge is the result of collaboration among the Municipality of North Cowichan, the Duncan Rotary Club, TimberWest (which owns the lake bottom), Woodmere Strata Corporation and Aquatech Environmental Systems.
The problem? Quamichan Lake has an excess amount of nutrients arriving in the runoff from the surrounding residential and agricultural properties.
While supporting the growth of trout placed in the lake by the Freshwater Fisheries Society of BC and their food chain – crayfish and protozoa daphnia as well as algae – difficulties occur when summer ends.
When the water is warm the algae starts to die off, resulting in stale water. The trout and their food chain are caught between water with low oxygen and that with too high a temperature.
Conversations about a solution led to building a system that disburses compressed air through 1,500 feet of fine bubble aeration pipe.
It both cools and aerates the water, offering a lifeline for large numbers of trout and their food chain.
According to Jim Cosh of the Quamichan Stewards, "All of this really started with Dave Groves, who had a fish farm. I looked where the wastewater came out and settled. He used aeration in it and it was pristine. There were salmon swimming around. We were very impressed.
"He introduced me to Allan Tweten of Aquatech, the guy who has the aeration line that’s running out there. After several conversations we decided that it would be a good idea to put in a trout refuge here in front of Woodmere."
Losing the oxygen in their water as algae die off in summer heat can lead to a fish kill.
"We can lose 50-100 fish. And those would be the ones you would see. The idea is here’s a way to get an area of the lake that’s aerated: a place for fish to come and hang out," Cosh said.
So, with that idea in mind, the Quamichan stewards thought it would be a good plan to try it.
An involved process followed during which they worked with North Cowichan and TimberWest.
"That started approximately 14 months ago. Then having gotten that in place, we needed the cooperation of this housing development, Woodmere, because the header pipes run along their foreshore. You can’t see them but it’s still really important to have a place to work from and get them installed," he said.
Next up was a home for a compressor.
Collaboration with the Duncan Rotary Club, TimberWest and North Cowichan saw that through to a successful conclusion.
"And North Cowichan will look after the maintenance of the compressor. That was important to us because as an all-volunteer organization, we come and go and we wanted to make sure it actually runs," he said.
Cosh himself owned aeration line and donated it.
"The Quamichan Stewards put up the money to buy the compressor. It was about $7,500 for the compressor and the related equipment. And the Rotary Club built the shed, for about $2,500 and a great deal of labour from the guys."
Groves and Tweten were involved and "about Aug. 11 we actually flipped the switch and started the compressor. I had lots of trepidation; my big fear was that the thing would make a hell of a noise and everyone here would hate me. Fortunately it was very quiet. That was a big relief. Then we had bubbles in the lake. We’re incredibly pleased with it," Cosh said.
The system won’t cure all of the lake’s ills.
"If it ran continuously it would do a lot more," Tweten said. "But running it for the time you’re planning to, it can only do so much as far as rehabilitating the lake. A lake of this size would need several stations like this to have a noticeable effect but in areas like this where there isn’t much wind effect, you’ll definitely see an effect on the bio-solids on the bottom."
Groves added, "This aeration system is pulling muck up slowly off the bottom where there’s no oxygen and that is encouraging it to metabolize. One of the things we have to do eventually is to move those lines 20 feet one way or the other because they will tend to eat their way down into the muck with this bubbling action. But, over a period of time the bottom will clear.
"This is the worst part of the lake. It doesn’t matter which way the wind is blowing. The bloom always comes ashore somewhere between here and Art Mann Park."
Following the official opening, the crowd moved to the side of the lake where they could see the bubbling from pipes and equipment.