The City of Portage la Prairie is exploring solutions after learning their license to purchase the herbicide used to manage aquatic plants on Crescent Lake was denied earlier this spring. City manager Nathan Peto says they had little notice of the changes taking place, "As we went to purchase the license and product this year, we were informed there has been legislation changes at the federal and provincial level that are disallowing that aquatic herbicide to be sprayed on fish bearing lakes. I know people don't traditionally consider Crescent Lake to be fish bearing but we do have small fish what they call 'forage fish' that do survive the winter and since those are protected under the legislation, we were prevented from buying that chemical and we are being told we are not permitted to spray the lake this year."

Peto explains the city petitioned to proceed with spraying this year while developing a management strategy for future years, "In discussions with the federal and provincial departments that regulate this we proposed assessing the lake to determine how we could use the chemical but not impact fish species downstream, however the regulatory bodies have maintained a firm position." In light of the limitations, Peto says an increase in aquatic vegetation is a certainty this year. 

"We are evaluating our options but right now the important thing is we want people to know that spraying will not happen this year. We are investigating other options but citizens and people visiting our community should expect not the same level of service we have had in the past. Weeds will grow higher, there will be more aquatic plant species on the lake. We don't know exactly what to expect since we've been spraying the lake for over a decade and prior that we used a weed harvester, so there's going to be a new look to Crescent Lake. We're investigating how we can maintain it, but our primary tool has been taken away"  

He says they've kept lake levels high in an effort to curb plant growth and visibility, "Many people don't recognize that Crescent Lake is manually pumped in from the river. The city owns two pumps that come in under the highway and maintain those levels. This year because of the rainfall we haven't used those pumps, but we also control the level of the lake with a weir at the other end of the lake that drains into Garrioch Creek and then back into the Assiniboine. So we do have the ability to control the level of the lake significantly. It's been working well so far but eventually the plants will catch up and start to grow in across the lake. We'll continue to keep the water fairly high, as high as we can without impacting property owners." 


Crescent Lake weed control map Map of areas previously receiving weed control treatment (treated areas in yellow and untreated areas in blue)


Photo of untreated portion of Crescent Lake in mid-AugustPhoto of untreated portion of Crescent Lake in August 2023 (submitted photo)