Gull Lake Watershed Society was at Lacombe County seeking support for an innovative project to protect the lake from Prussian carp while allowing a lake stabilization program to continue.
Last year, Alberta Environment and Parks suspended licences that allowed water to be pumped from rivers into Gull and Buffalo lakes as part of a long-running but infrequently used program to maintain lake levels.
The department says in an Oct. 31 letter to Lacombe County that the pumping licences were suspended because carp “are known and continue to expand their range in the Red Deer River basin.”
Earlier this year, about 1,000 were found in the channel leading to the pumping station that feeds Gull Lake.
But society secretary Norval Horner told Lacombe County council on Friday that it is important to continue the stabilization program to prevent lake levels falling further, which would have a big impact on fish and waterfowl habitats and on recreation.
“There would be a major impact on the lake and all your ratepayers who live on the lake,” he said.
Between 1924 — when lake levels were first measured — and 1975 the water level dropped 2.6 metres. Without topping up from Blindman River, the level could drop another metre before it stabilizes, he told council.
The society has been working with Red Deer County-based Lambourne Environmental on a filtering system using “geotubes” that would screen out carp and their eggs before the pumped water hits the lakes. Lambourne uses similar technology to screen wastewater for municipalities.
Horner was seeking council’s support to help their case when they go to Alberta Environment and Parks for approval of the filter idea. To ensure all larvae and eggs are are caught, water would pass through two geotubes, which are like huge bags made of fine geo-textile mesh that carp eggs and larvae can’t get through. Further downstream, the water would be checked to make sure it is clear of eggs or larvae before reaching the lake.
Coun. Ken Wigmore was concerned that if any Prussian carp were found in the lake after river water pumping resumed the county could be blamed and be expected to fix the problem, even if the filter system was not at fault.
“I think that’s the biggest concern,” he said.
Coun. Brenda Knight questioned whether it was premature for the county to back the project before Alberta Environment and Parks had shown a willingness to go ahead.
Council referred the issue to administration, which will bring a report back to a future council meeting.