Testing has shown that levels of Escherichia coli were within recreational water quality guidelines at most beaches monitored this week by Manitoba Water Stewardship.
Escherichia coli counts were above the guideline at Gimli beach on July 16, but quickly returned to within guideline by July 17. Exceedance of the guideline of 200 E. coli/100 mL was likely caused by severe 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.
Escherichia coli counts were also above the guideline on July 22 at Twin Beaches on Lake Manitoba. The beach has been re-sampled and results are expected tomorrow.
No algal blooms were reported this week from Manitoba beaches. Algal blooms often appear in Manitoba Lakes during July and can last until mid-September. Since algal blooms can reoccur during period of warm and calm weather, bathers are reminded to avoid swimming in water where severe algal blooms are visible.
Results for all beaches across Manitoba are posted as they become available on Water Stewardship’s website.
Each summer, Manitoba Water Stewardship routinely monitors about 60 beaches in Manitoba.
