SWIMMING at beaches on the Mornington Peninsula is off limits until further notice after heavy rain has caused poor water quality.
The Environment Protection Authority says all Port Phillip beaches are currently unsuitable for swimming, fishing or other recreational activity.
Meanwhile, signs remain in place warning against any contact with the water at Gunnamatta.
The signs erected by Melbourne Water two weeks ago say, “local water has been impacted by a recent incident” and people and pets should avoid any contact until the signs are removed (“Signing up to save environment” The News 18/10/22).
Satellite images from 17 October show brown stormwater flooding into Port Phillip after recent storms, with more heavy falls over the weekend.
Stormwater pollution is the major issue facing the bay and its inhabitants, as it is can be contaminated with sediment, nutrients, toxins, chemicals and litter.
EPA forecasts are based on rain, water quality history, sunlight, weekly sampling, and pollution reports. The authority monitors recreational water quality at 36 beaches in Port Phillip.
The authority advises against swimming for up to 48 hours after heavy rain as there may be a higher risk of illness to swimmers from increased bacterial levels.
Heavy rain and storms are highest risk to the public when they follow extended periods of dry weather as the “first flush” of the stormwater system carries most of the pollution that has built up in the drains into the bay.
Clean Ocean Foundation CEO John Gemmill predicted that warnings against polluted waters over the Cup weekend “may well become increasingly regular events”.
The advice from Melbourne Water is not to engage in any recreational activities including swimming and surfing at or near Gunnamatta, which is part of Mornington Peninsula National Park.
“Poorly treated waste has been dumped near the popular surfing beach, making the coastline and its waters unsafe for the past two weeks,” Gemmill said. “Heavy rains that caused flooding in Melbourne also caused the Eastern Treatment Plant [near Bangholme] to fail. The plant processes sewage from more than half of Melbourne’s population.”
Gemmell said polluted beaches could become more common as Melbourne’s population was set to double by 2050 “and the impacts of climate change to increase in severity”.
“Is this to be the future of our beaches – dumping grounds for human waste when waste water treatment fails?
“Without a major commitment to upgrade our waste water infrastructure, these events will damage our precious marine environment, state’s reputation for clean beaches, tourism as well as the health and wellbeing of its recreational users.”