The Environment Protection Authority has given all of Port Phillip Bay's 36 beaches, in Melbourne, Australia, a "poor" water quality rating.
If the EPA rates a beach as "poor" it is deemed unsuitable for swimming.
On Sunday evening Melbourne was hammered with rain, receiving one month's worth in a single night. The downpour resulted in stormwater and fecal matter flowing into Port Phillip Bay.
The EPA's Dr Anthony Boxshall told The Age children and senior citizens were most at risk of becoming ill if they swam at any of the 36 beaches.
"It's gastro that we're worried about and infections," he said. "If someone had an open wound on their hand, you can get pathogens."
In January this year the EPA listed 21 Port Phillip Bay beaches as having "poor" water quality after heavy storms resulted in "fecal contamination". Really, it's just a part of living in Melbourne now.