Several beaches deemed unsafe as Toronto staggers into another blazingly hot weekend – Toronto Star

Significant flooding in Toronto earlier this week means that three of the citys beaches are currently unsafe to swim.

As of Friday afternoon, Marie Curtis Park East Beach, Sunnyside Beach and Hanlans Point have all been deemed unsafe for swimming due to increased levels of E. coli. After major rainfalls, conditions are ripe for bacteria.

So whats happening to our waterways when it rains? According to Roberto Quinlan, an associate professor of biology at York University, major rain events in urban areas lead to a big pulse of debris and nutrients into the waterways.

These nutrients fuel bacterial growth, which in turn lead to water conditions that arent safe for swimming, Quinlan said. In some cases, after a heavy rainfall the sewage system becomes overwhelmed and you just get to release the raw sewage directly into Torontos waterways.

Thats a big health concern especially for those hoping to swim and cool off in the lake this weekend. Unless there is increased capacity for storm runoff, were going to see more of these type of events where youre going to have sewage overflows into waterways, Quinlan said.

Beaches could be closed more often due to poor water quality as extreme storms become more frequent. With temperatures rising, conditions will be ripe for blue-green algae, which is highly toxic to humans and animals alike. (Algae) are expected to bloom more frequently in warmer water temperatures, even if you dont change the amount of nutrients that goes into water, Quinlan explained.

So even if we do a really good job of keeping the water quality the same as it always is, just because of temperature increases alone, we would expect to see more frequent cyanobacteria blooms in the future.

Miriam Diamond, a professor of environment science with the University of Toronto, said that Ontarios developed shoreline means more waste heading to the lake after major rainfalls. Were dirty. We drive cars, we have pets that poop, we create a lot of waste. It collects on the street, and especially when it hasnt rained a lot ... it gets flushed into the lake.

While the lake can clean itself to some extent, it cant when theres too much rain, she said. Normally, animal feces would usually sink into the forest floor something that isnt as possible in an urban environment.

We have some trees, but there are vast swaths of lawns that are terrible at taking up these kinds of contaminants. That means that waste that would typically break down into the soil is flushed down into the late especially when theres a storm surge, Diamond said.

Both Diamond and Quinlan urged Torontonians that are hoping to take a dip this weekend to check for water advisories before they go.

People should be looking out for signs and either the OK or not OK to go into the water, Diamond said.

Never miss the latest news from the Star, including up-to-date coronavirus coverage, with our email newsletters

Toronto Public Health updates lake water conditions every 24 hours following E. coli samples. Swimmers should check their local beach before heading out.

In an email, Torontos associate medical office of health Vinita Dubey said that while the health department is still encouraging folks to get outside during the weather, we are still advising to avoid public gatherings and large crowds where physical distancing cannot be maintained, including beaches, due to COVID-19.