Stormwater quality

The new Stormwater Quality Bylaw 2020 was adopted by Council on 8 December 2020 and comes into effect from 1 February 2021.

Why is a stormwater quality bylaw necessary?

Stormwater does not get treated before it enters the environment, other than the removal of litter, debris and silt by mudtanks (if the stormwater passes through them). It is collected into the piped network, often via street drains, and discharges straight into the nearest stream, the harbour or the coast.

The bylaw makes it unlawful to tip, wash or flush common pollutants down our stormwater drains. Common pollutants include: water containing cleaning products; oils; paint or water from washing painting equipment; sand or water blasting waste; radiator coolant; pesticides/insecticides; solvents; trench water and spa or swimming pool water.

Run-off from construction sites requires pre-treatment to remove sediments before being discharged to stormwater.

The Otago Regional Council is responsible for regulating discharges of contaminants to the environment.  The DCC hold some resource consents for the discharge of stormwater from its public stormwater system, while other discharges are permitted, provided certain requirements are met.  Those requirements include the removal of any contaminants that could cause significant adverse environmental effects. This bylaw helps the DCC to comply with ORC requirements.

What does the Stormwater Quality Bylaw 2020 mean for me?

The bylaw contributes towards cleaning up Otago Harbour and other sites around our coast and waterways, meaning all of us will be able to enjoy a healthier environment.

You need to ensure your stormwater drains only drain rain.  This means you will need to either collect contaminated water or pollutants and take it to appropriate facilities for disposal or divert small amounts of contaminated run-off onto your lawn, garden or compost.

If you create larger quantities of contaminated water or other pollutants that requires disposal, you may need to apply for a Trade Waste consent

What are the rules for washing cars?

Detergents and car wash cleaners are contaminants that may impact on aquatic life if they are discharged into waterways and the harbour, via the stormwater system. Dust and dirt washed off cars are also contaminants and can have adverse impacts on the stormwater system and the environment. They should not be discharged into the stormwater system.

If you’re washing your car at home, stop soapy water flowing through the stormwater system and into waterways and the harbour by washing on a gravel or grassed area or by diverting your waste water through one, so it’s filtered before it runs into the stormwater system. Filtering through soil helps remove or break down contaminants. Other filtering options are also available such as filter cloth or mats or hay bales over stormwater drains will help reduce some contaminants and could be combined with minimal use of detergents or soaps.

To reduce contaminants, you should only use small amounts of cleaners. Cleaning without water or using only clean water (no detergents or soaps) are good alternatives. Using an environmentally-friendly cleaning product may have less impact on aquatic life than some other cleaners but is not by itself enough. A combination of methods to reduce contaminants should be used.

Businesses that wash cars or trucks as part of their normal business activities such as commercial car washes, car yards and transport/bus depots, generally have (or should have) special wash pad areas that discharge water from washing vehicles to the wastewater system or may use alternative methods for washing vehicles, such as just using water (no detergents or soaps). Water from commercial vehicle washing cannot be discharged to the stormwater system. It can be discharged to the wastewater system with a trade waste consent.

Car wash fundraisers create large volumes of soapy water. Soapy water cannot be discharged to the stormwater system. A trade waste consent can be granted for discharge of soapy water to the wastewater system.  You may be able to find a business with a special wash pad area that you can use for your fundraiser.

Contact the DCC education and compliance officer on 477 4000 for more information if you are proposing to have a car wash fundraiser or for advice about preventing polluting waterways when washing your car at home. Information is also on the preventing stormwater pollution page.

If I have water from washing/cleaning something (e.g. paint brushes, floors, carpet, the dog or windows), what should I do with it?

Contaminated water cannot be disposed of into the stormwater system. It is best to dispose of household wastewater down your sink. Ensure you don’t tip it into a stormwater drain. Small amounts may also be disposed of on a grass or gravel area.

If you are running a business, any discharge to the wastewater system must comply with the Trade Waste Bylaw 2020. Waste from your business cannot be discharged into a wastewater drain without DCC approval.

Where do I dispose of water from my pool or spa?

Swimming and spa pool water can contain chemicals which are added to kill harmful bacteria and/or algae. This water must not be discharged to the stormwater system.

Filtered backwash water must be discharged to the wastewater system. Cartridge filters should be washed onto the lawn or into the wastewater system. Spent diatomaceous earth should be composted or disposed of as rubbish.

Wherever possible, drain pool water to your lawn or garden and make sure the water does not flow off your property. Private pool owners may discharge pool water to the wastewater system. This should only be done when it's not raining. This minimises the risk of flooding occurring if the wastewater system is overloaded during a rainfall event.

If you need to drain a commercial pool (e.g. from a motel or school), you must get approval from the DCC to discharge to the wastewater system. You need to contact the DCC SeniorEducation and Compliance Officer on 477 4000 to find out if disposal to the wastewater system is permitted with only needing to register the discharge with DCC, or if you need a trade waste consent for the discharge.

For a comprehensive list of what should and shouldn’t be discharged to the stormwater system go to preventing stormwater pollution page

What should I do if I see someone polluting stormwater?

You can contact the Dunedin City Council on 477 4000 or the Otago Regional Council on 0800 800 033 (staffed 24 hrs a day) or email pollution@orc.govt.nz.

What are the consequences for breaching the bylaw?

The DCC may:

• require the discharger to undertake remediation or clean up the discharge
• undertake remediation or clean up the discharge and recover cost from the discharger
• issue an infringement notice
• prosecute a discharger through the courts.  The maximum penalty on conviction for a breach of the bylaw is a fine up to $20,000.