Zoe Cawthorn
Updated: Feb 25, 2020
A city council in Australia is using a simple but effective solution to clean up rubbish from the city's drainage system. The installation of catch nets on out-pipes in Kwinana City is preventing 75kg of rubbish entering the neighbouring nature reserves every month, creating a cleaner environment, safer habitats for wildlife and cost savings for the city.

Rain water from roads and roofs is often collected and discharged to natural water sources.

Rubbish, such as dropped litter, often finds its way into these drainage systems. When the litter is discharged from the pipe it flows into rivers, or is strewn onto the land, where it can cause harm to wildlife and contaminate the soil. Plastic is a particular problem as it can take over 500 years to decompose and contains harmful chemicals. In Kwinana City, Western Australia, rubbish in the city's storm water drainage system was being scattered all over the neighbouring nature reserve.
The local authority (City of Kwinana) has now fixed nets to the outlets of their drainage pipes, which are located between residential areas and nature reserves. This allows the rubbish (typically cans, food wrapping and plastic bottles) to be collected at the discharge point. The nets are easily lifted and emptied directly into a truck, by a 2-person team using a machine. The waste is then transported to a facility where green waste is converted to mulch and the remaining waste is sorted into recyclable and non-recyclable materials.
This simple but highly effective solution protects local wildlife habitats from pollution and creates a healthier natural environment surrounding the city. Five months after the nets were installed, the city's Mayor, Carol Adams, reported:
"If it was not for the drainage nets, 370kg of debris would have ended up in our reserve... to date no wildlife has been caught up in either of the city's nets.”
The nets cost the city just under $20,000 (AUS), which included the cost of design, manufacture and installation of the two units. However, City of Kwinana is achieving considerable cost savings due to the huge reduction in labour intensive work, previously required to collect by hand the rubbish that was scattered around the reserve.