Manitoba Water Stewardship advises testing has shown levels of Escherichia coli (E. coli) were within recreational water quality guidelines at most beaches monitored this week by the department.
Escherichia coli counts were above the guideline at Patricia beach on July 6 but quickly returned to within guidelines by July 7. Escherichia coli counts were also above the guideline at Gimli beach on July 7, but fell below the guidelines by July 8. Exceedance of the guideline of 200 E. coli/100 ml was likely caused by the weather conditions that caused winds and waves to wash bacteria out of the sand and into the bathing water.
On Lake Winnipeg, weather and lake level information appear to be good predictors of E. coli levels. Bacteria counts tend to increase when strong northerly winds cause water levels to temporarily increase and large waves wash bacteria out of beach sand. When calmer weather returns, E. coli bacteria levels typically fall quickly to below guideline levels.
An algae bloom was reported at Grand Beach lagoon near Lake Winnipeg on July 8. The number of blue-green algae cells was above the recreational water quality guideline and an algae advisory sign has been posted to provide cautionary advice to bathers. The concentration of an algae toxin, microcystin-LR, was below the recreational water quality guideline in the Grand Beach lagoon.
Algae blooms often appear in Manitoba Lakes during July and can last until mid-September. Since algae blooms can reoccur during period of warm and calm weather, bathers are reminded to avoid swimming in water where severe algae blooms are visible.
Results for all beaches across Manitoba are posted as they become available on Manitoba Water Stewardship’s website.
Each summer, Manitoba Water Stewardship routinely monitors about 60 beaches in Manitoba.
