Mind the grate: Reducing stormwater pollution at home
Environment Canterbury media release: 7th May 2024
Stormwater is water that runs off our roofs, driveways, footpaths, roads, and gardens. On its journey to the drain, it picks up a heap of contaminants (pollution) and flows untreated into our rivers, streams and the sea. Do your bit to help keep our stormwater clean.
In Canterbury’s urban centres, stormwater grates line the sides of our streets. Many people assume that what goes down these drains must get treated, but this is not the case in most situations.
Stormwater can pick up a number of pollutants like rubbish and debris, chemicals, spills and soil.
Construction and maintenance to improve stormwater quality comes at a hefty cost to Councils, and ratepayers foot the bill. This is why prevention is key when it comes to fighting pollution and keeping our stormwater clean.
We’re asking people to help make our waterways cleaner, healthier, and safer by being mindful when doing everyday projects around the house.
Household contaminants can pollute stormwater
When we aren’t tidy about how we do DIY activities around our homes, gardens, and vehicles, we can add nasty chemicals and other pollutants like sediment to our stormwater network.
Common household projects like painting or car washing can mean the use of toxic substances and detergents outside. Using these products improperly, or not cleaning up well after the job is done, can mean real problems for the waterways in our region.
Wastewater collected from the drains in our kitchens, bathrooms and laundries gets treated for contaminants. However water collected from the drains outside of our home doesn’t get the same treatment.
Dr Elaine Moriarty, Surface Water Science Manager, explains the impact of polluted stormwater:
“If we aren’t mindful about what ends up down our stormwater drains, we’re introducing toxic contaminants that can have serious negative effects on our precious waterways.”
“When we think about the environmental impact of something like paint, a little can go a long way. Even small amounts tipped down a stormwater drain can kill fish like tuna/eels and īnanga/whitebait, aquatic insects, and vegetation – ruining habitats.”
Tips to protect our stormwater
Be mindful of our stormwater drains and follow these simple tips for a healthier environment.
- Paint clean up
When painting around the house, wash brushes in the sink, not down the drains outside.
Use the two-bucket method for bigger painting projects with more brushes, rollers and trays. This method collects paint solids for the bin.
- Household projects: Sweep up any sawdust and leftover bits and pieces. Ensure scraps and rubbish go in the red bin.
- Landscaping: Put garden waste in your green bin or your home compost, and protect soil from rain by covering so that it does not wash into stormwater.
- Be careful with sprays and fertilisers: When using sprays or fertilisers in your garden and around your home, always make sure to use them away from areas where water may run into stormwater grates.
- Car washing: Wash your car on the lawn, grass verge, or at a car wash. It stops cleaning chemicals and dirt and grease from going into the stormwater system.
Find more tips on how to protect our stormwater.
“Help protect our waterways by carrying out household projects and chores responsibly by taking care to ensure that litter, detergents, paint or other solvents don’t end up in our stormwater network next time it rains,” said Dr Moriarty.
“This way, we can keep our waterways clean and safe for everyone to enjoy.”
Simple ways to protect our waterways
Preventing nasty poisons from entering our local and coastal waterways starts at home.
Get tips on how to protect our waterways on the Environment Canterbury website. Please share this information with your friends, family and community groups.
Report anything blocking or running into a stormwater drain by:
Dispose of leftover or unwanted paint or solvents safely at an EcoDrop Recycling Centre, or at your local Council's transfer station locations.