Floodwaters can carry a range of disease-causing microorganisms (pathogens) and chemicals into our rivers and waterways.

On this page

Flood responsibilities by organisation

 

There are many health risks associated with floodwaters. Avoid contact if possible. If you feel unwell after exposure to a flood-impacted waterway, contact your doctor for advice.

 

What we test for

To understand the risk to human health from contact with floodwater, we are monitoring E. coli bacteria, and contaminants of potential concern (COPC) at targeted sites. You can download the test results, or keep reading for more information.

Bacterial indicators of faecal contamination

E. coli bacteria are one of the many groups of bacteria found in the intestines of humans and warm-blooded animals. They are a useful indicator of faecal contamination from sewage or animal manure. Levels of E. coli fluctuate. They often increase quickly after heavy rainfall due to runoff and flooding, but then decrease quickly. In marine waters, we monitor enterococci, another bacterial indicator, which survives longer in salted water.

Monitoring during the 2022 Victorian floods

In October 2022, EPA monitored the water quality of 24 waterways at 46 locations across Victoria at waterways with high recreational use.   

Download the test results

We tested water, sediment and soil samples from flood-impacted waterways to understand the level of risk to human health and the environment. Monitoring results were reviewed against health and environmental guideline values.

About the soil data from the flood-impacted Maribyrnong River

We received results from 135 soil samples taken from flood-impacted areas around Maribyrnong River. Results received from impacted gardens indicated contaminants were generally below levels of concern. Some of the residential areas with higher levels are likely due to legacy contamination issues.

Contaminants of potential concern (COPC)

Some waterways were tested for COPC. This included metals and chemicals such as petroleum hydrocarbons and perfluoroalkyl and polyfluoroalkyl substances (PFAS). Data collected indicated COPC were below levels of concern for recreational water use.

For more information on Victoria's water quality

Support from other agencies

Part of this sampling was done in conjunction with the Victorian State Emergency Service (VICSES) with support from Natural Hazards Research Australia. 

 

Reviewed 13 September 2024