Only rain down the drain

Most of us would never tip paint or chemicals into a stream or the sea and would be angry if we saw someone else doing that. We might even report them to the authorities. But many of us also don’t understand what happens to water once it goes down the sink or the drain, and this can lead to people inadvertently polluting local streams – which of course eventually gets to the sea.

Water leaves your property down two different systems. Inside the house, your toilets and sinks are connected to the wastewater system, and this water is treated at a water treatment plant to remove any pollutants before it is recycled or discharged. Outside the house and out on the street, drains are designed for rain, and are connected to the stormwater system. These pipes flow to a nearby waterway, like an estuary or stream, and the water is not treated on the way there. This means anything washed down the drain, like paint or garden chemicals, or soapy, dirty water from washing the car, goes straight to our natural environment, where it can cause a multitude of problems.

Our streams and waterways are home to many native fish, insects, plants and birds. Pollution can restrict sunlight from reaching them, smother them, clog up the gills and eyes of fish, reduce oxygen in the water, and poison them.

Even natural products like garden waste or large amounts of soil can cause problems. If you see a stream or waterway that looks polluted, you can call the Pollution Hotline 09 377 3107, 24 hours a day, seven days a week) and an expert will come and investigate.

There are a few simple things you can do to make sure you don’t cause a pollution event. Wash your car on the grass, or at a carwash. Use water-based paint, and wipe excess paint off brushes onto newspaper, then wash in an indoor sink or onto grass or gravel. Don’t put lawn clippings, soil, pool or spa water, oil or household chemicals down the drain. You can also help by picking up litter or joining a streamside planting event.

Remember, drains are for rain!

Paint flowing into a wetland in Hobsonville Point in 2021.