Toronto's Sunnyside Gus-Ryder Pool has reopened for swimming, but the nearby beach and park will likely remain closed until at least Sunday.

City officials deemed Sunnyside Beach and park a potential health risk on Wednesday morning following Tuesday night's violent thunderstorm.

The large amount of sudden rainfall caused a storm sewer in the area to overflow. The mix of rainwater and sewage spilled into the beach water and nearby park and children's wading pool.

Officials placed some of the blame for the problem on the city's aging infrastructure.

Authorities fenced off the Sunnyside area from the Palais Royale Ballroom to the beach. It will remain closed until officials deem the lake water safe.

Sunnyside Gus-Ryder Pool was closed all day Wednesday as a precaution, but it has been deemed safe and is open again.

Pool managers have added more chlorine to the water as another precaution and to make swimmers feel safe.

For updated conditions on Sunnyside Beach and other Toronto beaches, click here.

With a report from CTV Toronto's Dana Levenson