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 Gimli Beach on July 31, but returned to within guideline limits by Aug. 4.
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 algal bloom was reported at Killarney Lake on Aug. 5. The number of blue-green algae cells was above the recreational water quality guideline of 100,000 cells per ml at Killarney Lake beach. The beach was posted with an algae advisory sign in July and will remain posted for the rest of the season. The concentration of the algal toxin microcystin-LR was below the guideline.
Re-sampling at Meditation Lake has shown that the number of blue-green algae cells has returned to below the proposed recreational water quality guideline. The concentration of the algal toxin microcystin-LR was also below the guideline.
Algae blooms often appear in Manitoba Lakes at this time of the year and can last until mid September. The formation of algae blooms is difficult to predict, however warm and calm weather coupled with relatively high nutrient loads create ideal conditions for their development. Swimmers are reminded to avoid swimming in water if 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.
