Geese droppings and sediment release into the lake account for 88 per cent of the 26.26 kilograms of total phosphorus examined in the study
Photo by Ed Kaiser /Postmedia
Public swimming at Hawrelak Park Lake may never be in the cards for an Edmonton summer activity because of poor water quality largely caused by goose droppings.
But a $2-million investment could improve the water quality in the popular river valley park enough to expand water activities with limited contact, including paddle boarding and kayaking.
Responding to a January 2020 request from council to explore usage options, the city conducted an in-depth water quality study to explore the feasibility of making the lake swimmable. Even by identifying six management practices to help improve water quality, it was determined it wouldn’t be enough to make the lake safe to swim on a regular basis.
The root cause of the poor quality was deemed to be high phosphorus levels which can cause excessive growth of algae, create blue-green algae and reduce the amount of oxygen in water. Geese droppings and sediment release into the lake account for 88 per cent of the 26.26 kilograms of total phosphorus examined in the study. A proposed $15,000 goose management strategy would help reduce phosphorous levels, but has its limits.
“Implementation of the recommended measures does not include “in the water” experiences such as wading and swimming due to the limitation to water quality standards that can be achieved through the best management practices,” the city said in its report. “Canada Geese are protected under the Migratory Birds Convention Act and interventions with geese populations are controlled federally. As such, there is a limit to the water quality standard that can be achieved.”
Moving forward on a 10-year rehabilitation project of the 68-hectare park, the city will also be requesting $2 million from council as well as annual maintenance costs of $100,000 to improve the water quality. This would include removing sediment as well as planting shrubs and shoreline buffers.
When the city last looked at making the lake swimmable in 2011, the projected cost was $60 million to line the lake and make it more like a pool. The city has in the past made the lake temporarily swimmable for international triathlon events, mostly through chlorination to meet the necessary health regulations, costing about $70,000 annually.
Area Coun. Ben Henderson said he is happy to see the city looking to make some improvements to make the lake more approachable and allow for limited water contact without a constant fear of blue-green algae.
“I think that’s good news. I think knowing how dangerous blue-green algae is I think we need to do whatever we can to make sure there isn’t blue-green algae in there, but that’s different than saying its going to be a swimmable lake,” he said. “I think if we can do some simple things to improve the quality of the water, we should absolutely be doing that.”
The 1.5-metre deep lake is an artificial body of water that was designed to manage stormwater in the park when it opened in 1967.
Construction on the rehabilitation project is scheduled to begin in 2023 and might require multi-year closures.