Central Interceptor

Among other benefits this wastewater tunnel will reduce overflows by up to 80 per cent.

Start–finish: 2019–2025
Location: Western Springs to Māngere
Status: Tendering and procurement

Read the latest news about the Central Interceptor project.

Graphic showing the route of the Central Interceptor.

Diagram showing the project timeline

What’s happening?

The Central Interceptor is a wastewater tunnel that will run between Western Springs and the Māngere Wastewater Treatment Plant.

The tunnel will run underground for 13 kilometres and will be at a depth of between 22 and 110 metres, as shown below. 
It will cross Manukau Harbour at about 15 metres below the seabed. Along the route it will connect to the existing wastewater network, which will divert flows and overflows into the tunnel.  

Graphic showing where the pipe will run under the Manukau Harbour.
A diagram showing the proposed pipeline route

What are the benefits?

The Central Interceptor will:

Reduce environmental risk
The existing wastewater pipeline that passes under the Manukau Harbour was built in 1964 and is reaching the end of its operational life. Damage to, or failure of, this pipe could result in a significant discharge of untreated wastewater into the Manukau Harbour. The new Central Interceptor Tunnel will also include back-up generators at the new Māngere Pump Station in case of an unlikely extended power outage. Along with the recent $130 million biological nutrient removal upgrades to the Māngere Wastewater Treatment Plant, the Manukau Harbour will continue to be protected into the future.

Service a growing city 
Auckland is undergoing significant growth and must accommodate another one million people over the next 30 years. The Central Interceptor is critical to providing additional wastewater capacity for this growth and enabling the connection of future wastewater projects in response to growth. Connecting to the western end of the Ōrākei Wastewater Interceptor, the Central Interceptor will provide a more direct route to the Māngere Wastewater Treatment Plant for much of central Auckland’s wastewater flows. This will allow greater capacity for growth in other parts of the network. The Northern Interceptor, which begins construction in 2018, will divert some of the northern wastewater flows to Rosedale Wastewater Treatment Plant, freeing up of more capacity in the southern network to allow for future growth.

Help reduce wastewater overflows 
During wet weather the central wastewater network currently overflows to local waterways and the Waitematā Harbour at more than 100 locations and to the north-eastern Manukau Harbour at 14 locations. The Central Interceptor is expected to reduce the volume of overflows by over 80 per cent.

Watch a video explaining the project:


Any questions?

For general questions, please contact:
Email: CIProject@water.co.nz

If you would like to supply products or services, please contact:
Email: CIProject-suppliers@water.co.nz

More information

Media release (November 2018)
Media release (September 2018)
Central Interceptor review – Outcomes from the International Review Panel
Media release (May 2018)
Interested suppliers
Media release (March 2018)
Fact sheet 
Media release
Contractors' information

Consent documents

Hearing panel’s decision
Resource consent application
Project works evidence
Main works designation conditions – January 2014
Notice of Requirement 1 – August 2012
Notice of Requirement 2 – August 2012
Notice of Requirement 3 – March 2013
Main works resource consent conditions – December 2013
Network discharge consent decision and conditions – September 2014
Main works deviation consent and conditions – March 2018

Minutes of the Meola Creek Community Liaison Group meeting

Minutes for meeting 13 September 2018
Minutes for meeting 30 May 2018
Minutes for meeting 6 March 2018
Minutes for meeting 7 November 2017
Minutes for meeting 8 August 2017
Minutes for meeting 10 May 2017​ 
Minutes for meeting 14 December 2016
Minutes for meeting 4 July 2016