Why you should check the water quality before going for a swim in Victoria

St Kilda Beach

Jessica Taylor Yates

Posted January 10, 2023

Victoria's Chief Environmental Scientist explains why it’s important to check the quality of the water before heading for a dip at the local beach, river, or watering hole. 

While summer is usually synonymous with swims and building sandcastles, it is important to stay up to date with the water quality across the 36 Victorian beaches along Port Phillip Bay and the Yarra River so your health is not at risk. 

Victoria's Chief Environmental Scientist, Professor Mark Patrick Taylor, tells us why it is important to check water quality before heading in for a dip – and what you can do to make a difference.  

As well as protecting our environment, The Environmental Protection Authority (EPA) are responsible for protecting the environment and human health from pollution and waste. 

The EPA set daily forecasts for water quality based on rain, sun, history, pollution reports, and sampling of the water.  

Additionally, says Taylor, “[the EPA] provide guidance and advice that the community can use interactively on a daily basis to decide to go to the beach.”

How is water quality measured?  

The EPA provide a daily water quality beach report, which is interactive. 

A ‘water quality forecast key’ is used to determine whether the water along Port Phillip Bay and the Yarra River is suitable for swimming. This is done on a traffic-light based system of green, yellow and red as stated by the EPA:

  • Good – suitable for swimming
  • Fair – may not be suitable for swimming
  • Poor – not suitable for swimming

Water is sampled weekly, where it is investigated for traces of chemicals, plastics, pesticides and other chemicals that can lead to people being in contact with E coli. 

“E coli is used as a microbial measure for water quality,” says Taylor. “That can cause [illnesses such as] gastroenteritis and diarrhoea.” 

To make predictions, the EPA use the data alongside past, present and future weather reports to provide a forecast on whether water is safe to enter for swimming. 

How can I find out about the water quality in my area? 

To find out the latest Beach Report on water quality for your area, you can either head to the EPA website, or sign up for texts that alert you when your nominated beaches are forecast to have poor water quality. 

The site also has an interactive map where water quality can be observed in your area. 


Dog beach

You may want to double check the water quality before you let your family or your dog in for a dip. Image: Getty. 

Why the water quality been poor this summer

During the 2022-23 summer, many beaches on the EPA’s radar have been forecast to have a ‘Fair’ or ‘Poor’ rating. Much of this can be attributed to the recent floods in New South Wales and Victoria on the back of La Niña, which carry pollutions, toxins, and contaminants that can be dangerous to humans and animals. “Rainfall produces runoff, and that runoff will affect water quality in the bay,” says Taylor.  

“We’ve seen an increase in agricultural activities and industry [that] produce contaminants," he says. “Those then get washed into the bay which affects the water quality, and because that was happening on an almost daily basis, it was poor.” 

As a blanket rule, the EPA recommends avoiding beach areas for up to 48 hours after heavy rain and floods to avoid a higher risk of illness. Sometimes, these alerts continue for longer is the water is still considered unsafe to enter. 

So, will it be fine to swim in our magnificent beaches this summer? 

“It takes time for the for the water to improve,” he says. However, a run of clear skies helps enormously, and Taylor suggests things should usually get better "within about 24 to 48 hours."

“As the season’s gone on, and the weather's improved, so has the water quality. As long as the weather is good, I anticipate that our beaches continue on the whole to be looking fantastic and suitable for swimming.” 

Is it safe for my dog to go in the water? 

We all know dogs love the beach, and while pets seem to be more resilient to bacteria (drinking from puddles and the like), as a precautionary measure, Taylor says to stay on the safe side. “Even though they may be more resilient, it presents an additional risk to your pet.”

So, if you wouldn’t get in, best not to let your furry friend, either.


man on phone

Always remember to take safety precautions when at the beach. Image: Getty.  

Is there anything I can do to improve the water quality? 

Absolutely, says Taylor. “Think about what you do and what is going to go into our streams.” For example, he says, "making sure you don’t litter. Lend a helping hand and pick up rubbish you find and put it in the bin so it doesn’t end up in our bay. It not only affects us, but marine life."

Taylor also says to consider your daily behaviour, such as doing a DIY car wash. He recommends people do this on the lawn rather than concrete, where the products will get washed into the stormwater system.  

Another way to improve the water quality is what we do in the home. Taylor encourages people to think about how they discard of water and waste, and to ensure it goes down the proper channels – rather than flushing things down the sink, ensure they go in the bin, sewer, compost, or appropriate channels. 

“Little things matter,” says Taylor. “Even small behaviours by individuals can have a huge cumulative impact.” 

Health advice before swimming

As well as always staying safe at the beach by staying sun smart, swimming between the flags and these other beach safety tips, always ensure the water is healthy before getting in. According to the EPA, this means you should: 

  • Avoid swimming near stormwater drains 
  • Avoid swimming for 48 hours after rainfall
  • Try not to swallow water during recreation 
  • Cover cuts and scratches with waterproof bandages
  • Wash your skin with soap after touching the water and shower after swimming

Taylor adds that it is important to stay vigilant around water. “Know your swimming area. Don't go in there on your own, have somebody else with you. he says. “If the water looks funny, contaminated, or turbid, apply a precautionary approach and don't go in.”


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