
What’s going down your drain? Easy ways to reduce your stormwater pollution
Have you ever considered what happens to soap bubbles that disappear down the drain after washing your car? Or where leftover coconut oil ends up after washing pots and pans in your kitchen sink? What about dead leaves from non-native species in your garden?
The answer: usually in our waterways. Stormwater is rain that runs off human-made surfaces into drains that channel water into nearby waterways that eventually lead to larger bodies of water . For Melbourne, that larger body is Port Phillip Bay.
From first touchdown on earth somewhere in Melbourne and throughout its journey to Port Phillip Bay, rain picks up pollutants. Over 14 000 tonnes of sediment and nutrients per year, to be exact.
Waste and litter such as insecticides, pesticides, paint, detergents, solvents, used motor oil and other fluids impact the natural habitats of flora and fauna throughout the Bay’s ecosystem and create health hazards for humans enjoying recreational activities in the water.

Chemicals that we wash down the sink don’t just disappear; they often end up in waterways such as Port Phillip Bay. Image by Semevent from Pixabay.
Sediment and nutrients from stormwater compromise the ability for plants and animals to thrive in their natural environment. Sediment from stormwater can cloud water and make it difficult for aquatic plants to grow. Nutrients picked up from other places can increase algae blooms, which take oxygen from other plants and animals when decomposing. Litter can physically harm birds, fish and other aquatic animals if swallowed or attached to their bodies, whereas chemical pollutants can poison them.
Pollutants in stormwater affect humans as well. If they appear in swimming areas, health hazards may require beach closures and we can become sick from eating poisoned fish or shellfish from polluted water.
Stormwater pollution has four basic forms: chemical, litter, natural and bacterial. Citizens of Melbourne and its suburbs make direct contributions to all of these pollutants. If we do not dispose of our products safely, make sure our litter ends up and stays in a bin, use native species in our landscaping or stop food scraps from going down our kitchen sinks, we are contributing to pollution in Port Phillip Bay.
Port Phillip is a valuable ecosystem, one of the cleanest bays in nearby cities. We want to keep it that way, and improve its health further into the future. Sometimes small acts can make enormous differences.
This infographic provides some ways you can reduce pollutants that flow into the bay from our drains.
In addition to these prevention methods, you can help protect our Bay by harvesting rainwater as a valuable resource. Doing so reduces the amount of stormwater runoff and decreases water waste in daily housekeeping. Just by placing a tap on a rainwater tank, you could water your garden, wash your car or top up your pool in the summer. The garden alone accounts for 34% of household water use. The Victorian Environmental Protection Agency (EPA) has more information about how you can use rainwater around the house.
You can go a step further in protecting our Bay by implementing Water Sensitive Urban Design (WSUD) in your home for managing stormwater. A self-watering and low-maintenance raingarden is an excellent way to capture and filter stormwater before it reaches our waterways.

Image courtesy of Pete Stott [CC BY 2.0], via Flickr.
About author
Olivia Salsebery
Olivia is an international graduate student at Monash University studying International Sustainable Tourism Management. Her favourite thing about Melbourne is all the amazing bike paths along the city’s beautiful waterways.
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