Washing your car in the driveway is a thing of the past for Porirua residents.
The city council has passed a new bylaw - aimed at preventing pollution going into the Porirua Harbour.
People will need to wash their cars on grass, or at a commercial car wash facility, councillor Bronywn Kropp said.
Instead of soap suds and other nasties going down the drain into the water which goes straight to the harbour, it's filtered through grass and other plants, she said.
The focus of the bylaw is not to catch people out and fine them, but to educate them to help keep pollution out of Porirua's waterways, Ms Kropp said.
Waikato council agree with ban
Waikato Regional Council spokesman Stephen Ward said the council agreed with Porirua that letting chemicals used in car washing go down the drain into the stormwater system risks the health of freshwater waterways and coastal areas.
"We strongly encourage people to wash their cars on the grass or do them in a car wash. This is a good example of individual action that can help protect the environment.
"Thousands of people letting chemicals get into the stormwater system from car washing can have a cumulative negative effect - lots of people avoiding this happening can have a positive effect."
The council's rules say contaminants that can make their way to waterways should not go into the stormwater system.
Mr Ward said the council was taking an educative approach and would only be likely to take enforcement action in more extreme cases when it comes to car washing.
"But this is an issue we keep an eye on and we could step up our response in light of any new developments if required."
Tauranga City Council pollution prevention officer Radleigh Cairns said it did not have a specific bylaw for car washing, but we do have a stormwater pollution prevention bylaw which states that "no person shall allow the discharge of contaminants, either directly or indirectly, into any part of the public stormwater network unless the discharge is permitted by a rule in a regional plan; or is authorised by a resource consent."
"We focus on educating our communities about water pollution.
"We do this through education programmes and signs around Tauranga that have the attached message on them, to advise that:
• car washing is conducted on a grassed area, or better yet at a commercial wash facility.
• that car wash water is harmful to the environment. Detergents including those that are labelled as "eco-friendly" or "biodegradable" will harm aquatic life and can strip the protective membrane coats of fish and eels. Dirt, oils, grease and harmful heavy metals like zinc and lead will be washed off vehicles and make the wash water contaminated. These contaminants are harmful and heavy metals in particular can build up over time in river and marine sediments.
- Additional reporting: Newstalk ZB