For the last two weeks, 21 beaches around Port Phillip Bay including St Kilda, Elwood, Frankston, Seaford, Carrum, Aspendale, Mordialloc, Mentone, Beaumaris, Black Rock, Half Moon Bay, Sandringham, Hampton, Brighton, South Melbourne, Port Melbourne, Sandridge, Williamstown, Altona and Werribee have all been given below average water quality ratings due to fecal contamination and so this week, we thought we’d take a look at the reasons behind this.

St Kilda beach

What is stormwater?

As the name suggests, stormwater refers to the water which enters residential and council drains during a downpour. Of course it’s not the water itself which is the problem but the detritus it washes off roofs, gutters, roads and streets. Litter, bird, cow, human and dog faeces, oil and petrol, fertilizers, pesticides and a myriad of other hazardous chemicals and materials are the kinds of things that get washed into stormwater and it’s these that cause pollution problems.

Why does stormwater flow into the bay?  

Once stormwater run off Is collected in gutters and drains, it moves into retarding basins, wetlands and litter traps which slow down the stormwater and purify it. It then moves into larger ‘regional drains’ before making it’s way into rivers, creeks, and bays. In Melbourne, there are over 300 stormwater drains which empty into the bay from 10 municipalities. However, during periods of heavy rainfall like the one in 100 year storm event we experienced in the days after Christmas, the stormwater system is not able to manage such a large volume of water and so the detritus washes straight into the bay.

Can it make me sick?

Swimming in water affected by stormwater pollution is associated with a whole host of illnesses, the most common being skin irritation and gastroenteritis.

Is it possible to see stormwater pollution?

Whilst it’s not actually possible to see the enterococci bacteria that the EPA tests for in order to measure faecal contamination, there other signs of stormwater pollution which you can look out for. Flowing drains, an odour, litter along the shoreline, and discoloured water are some of the most obvious signs that stormwater pollution may be present in a body of water.


Whilst JPG Plumbing can’t do much about the water quality in Port Phillip Bay, we do provide blocked drain solutions for homes and businesses throughout Melbourne’s southeast suburbs. To learn more about our capabilities, please don’t hesitate to get in touch with us by calling 0400 978 442.