What happens to wastewater?

Wastewater is all the water that drains out of your sinks, washing machines and showers, and flushes down your toilet. You probably know it as sewage.

Our job is to collect your wastewater, treat it to a high standard so it doesn’t pollute the environment or make people sick, and then dispose of it responsibly. Our teams maintain and operate the wastewater network up to the connection point at your property, making sure it works smoothly and preventing smells and overflows. 

Dealing with wastewater for Auckland’s 1.7 million people is a big job. Every day we collect over 400 million litres of wastewater, which runs through a network of 18 treatment plants, 518 pump stations and more than 8,000km of pipes. 

Who’s responsible for wastewater and stormwater?

Stormwater is rain that doesn't absorb into the ground and needs to be collected so it doesn’t cause flooding. It flows from pipes and drains into the public stormwater network and then into streams and the sea. In Auckland, the stormwater network is managed by Auckland Council.

Wastewater is your used water, which also contains organic matter such as human waste, food scraps, fats and oils, and debris such as sand and plastic. Wastewater drains into gully traps and private wastewater pipes on your property. These connect to our wastewater network, which carries your household wastewater to treatment plants. 

How do you manage overflows?

Overflows are when wastewater spills out of pipes, drains or other parts of the network, then flows onto public or private property or into the environment or sea. They can occur when pipes become blocked or overwhelmed with stormwater. We realise the importance of minimising overflows and dealing with them quickly, so our maintenance crews are ready to respond, fix the problem and clean the area.

You can learn more about how we deal with overflows and how to reduce their likelihood in our FAQs and the links below.

Living near our treatment plants and dams

If you live downstream or near one of our treatment plants or dams, here are some tips to be prepared:

• Sign up to receive emergency response updates for your area. A dam breech is more likely during a natural disaster such as an earthquake or major flood.

• Find out if you are in a hazard zone and map the route to higher ground.

• Understand how Auckland Council and the Local Disaster Management Group manage emergency situations in your area.

• Have a disaster response plan and an emergency kit.

Our Rosedale Wastewater Treatment Plant dam is built to withstand a maximum probable likelihood earthquake and flood. If disaster strikes, the most likely scenario is that we’d have time to evacuate downstream areas in a calm and orderly manner. While a dam breech is highly unlikely, we still plan for worst case scenarios.