Map of major sewer upgrade

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Projects currently under construction

Pump Station 11

The existing Pump Station 11 in Randolph Street is being replaced with a new pumping station on the corner of Bass and Randolph Streets. The new Pump Station will have five times the capacity of the existing Pump Station 11, and 20% more capacity than the City's largest existing pumping station.

The new Pump Station 11 will receive flow from the Western Interceptor, Pressure Main 20 and some local Linwood catchment. Construction began on site in January 2005. The new Pump Station 11 started operating in May 2007. The pump station pipe-work in Bass and Randolph Streets will be completed as soon as possible.

This work reduces the likelihood of overflows into the Heathcote River during wet weather.

Western Interceptor Stage 1 sewer pipeline

The Western Interceptor Stage 1 is a 1km long, 1.6m diameter pipeline, which will connect an existing trunk sewer in Tuam Street with the new Pump Station 11. It will run from the Aldwins Road/Bass Street intersection, along Aldwins Road, along Harrow and Tuam Streets to the intersection of Tuam Street and Mathesons Road.

Construction of the Western Interceptor Stage 1 began in Aldwins Road at the intersection of Bass Street at the end August 2007. The work will progress along Aldwins Road and then into Harrow Street and Tuam Street. Stage 1 is expected to be completed in February 2009.

The Western Interceptor will reduce wet weather overflows to the Avon River and allow for growth in the south-west of the City. The future stages of the Western Interceptor, extending through the City to Riccarton, are currently planned for 2011 to 2015 (see "Planned work to come" below).

For more information:

• Western Interceptor Stage 1 sewer pipeline [PDF 582KB]

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Completed projects

A number of projects have been completed which will help reduce the likelihood of wastewater overflows into the Heathcote River during wet weather events.

These projects are:

Pressure Main 11

The new Pressure Main 11 is 3.7km long, 1.2m diameter wastewater pipeline connecting the new Pump Station 11 in Randolph Street to the Christchurch Wastewater Treatment Plant. It was completed in 2006, and put into operation with Pump Station 11 in 2007. A second new pressure main of the same diameter is planned for next decade.

Pump Station 20 Upgrade (Complete)

Pump Station 20 has been upgraded to double its pumping capacity. The upgraded Pump Station 20 pumps wastewater to Pump Station 11 via the new Pressure Main 20.

Pressure Main 20 (Complete)

The new Pressure Main 20 upgrade, completed in 2002, involved the construction of 1.9km of 750mm diameter concrete pressure main between Pump Station 20 and Pump Station 11.

Pump Station 21 (Complete)

The Pump Station 21 upgrade, completed in 2006, has increased the capacity of this Pump Station, located in Eastern Terrace, by more than three times. The upgraded Pump Station, pumps wastewater (from the local catchment and the Tennyson Street and Fisher Avenue overflow diversions) directly to Pump Station 20 via the new Pressure Main 21.

Tennyson St and Fisher Ave overflow diversion to Pump Station 21 (Complete)

This project involved the construction of two gravity wastewater pipelines along Eastern Terrace from Tennyson Street and Fisher Avenue to Pump Station 21.

These pipelines divert wastewater from the Tennyson Street and Fisher Avenue overflows to Pump Station 21 in wet weather, reducing the likelihood of wastewater overflowing into the Heathcote River.

Pressure Main 21 (Complete)

The new Pressure Main 21 involved the construction of a wastewater pipe from Pump Station 21 (Eastern Terrace) along Eastern and Fifield Terraces, to Pump Station 20 (Locarno Street).

This pipe will convey wastewater from the upgraded Pump Station 21 directly to the upgraded Pump Station 20, reducing the chances of a wastewater overflow into the Heathcote River during wet weather.

Pump Station 60 Upgrade (Complete)

The pump capacity of Pump Station 60 in Halswell Road has been increased to overcome a wet weather overflow problem at the station and to cater for future development in the Halswell area. The upgrade became operational late 2003 when the station was connected to the new Halswell pressure main.

Halswell Pressure Main Diversion Stage 1 (Complete)

Stage 1 of the new Halswell Pressure Main Diversion was completed in 2003. The purpose of the new 3.9km long, 450mm diameter pipeline is to redirect the Halswell flow away from the city's overloaded southern trunk sewer system to the existing Wigram trunk sewer at Wigram/Haytons Roads.

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Planned work to come

The following work is planned to reduce the likelihood of wastewater overflows into the Avon River during wet weather.

Western Interceptor

The planned Western Interceptor is a new 6km long pipeline, 1.2m to 1.6m diameter, to be laid between the existing Southern Relief Sewer in Riccarton (at the intersection of Dalgety Street and Blenheim Road) and the new Pump Station 11 in Linwood (at the corner of Bass and Randolph Streets).

It is a major component of the Major Sewer Upgrade, and will:

• reduce the load on the existing trunk system between Hagley Park and the Christchurch Wastewater Treatment Plant, reducing wet weather overflows to the Avon River.
• provide capacity for growth to the west and southwest of the City.

The planned route for the Western Interceptor is from Pump Station 11 along Bass Street, Aldwins Road, Harrow and Tuam Streets, Mathesons Road, St Asaph Street, through South Hagley Park, and along Blenheim Road to the intersection with Dalgety Street. Factors which were considered in choosing the route included pipeline feasibility and efficiency, planned sewer connections, construction cost and likely disruption.

Stage 1 of the Western Interceptor is currently under construction. Stage 1 is from the Aldwins Road/Bass Street intersection, along Aldwins Road, along Harrow and Tuam Streets to the intersection of Tuam Street and Mathesons Road. See Projects currently under construction above for further information.

The future stages of the Western Interceptor, from the Tuam Street/Mathesons Road intersection through to Blenheim Road, are planned for construction in 2009 to 2013.

The section of the Western Interceptor at the Blenheim Road deviation, which was previously planned for construction in 2006, has been delayed to coincide with the rest of the pipeline, due to concerns about the effect on traffic.

Avon Upgrade Works

The existing trunk sewers in Papanui, Fendalton and Riccarton have limited capacity. Options are currently being investigated to relieve these capacity issues and reduce wet weather overflows into the Avon River. These investigations are planned to be complete by mid-2008. The works are currently planned for construction from 2009 to 2015. These upgrades are currently shown on the Major Sewer Upgrade map as the "Maidstone Storage/Pump Station and Rising Main", "Grassmere Storage" and "Northern Relief Duplication", which are some of the options being investigated.

Halswell and South-west Christchurch Upgrade Works

The existing trunk sewer servicing the Halswell area also has limited capacity. Options are currently being investigated to relieve this capacity issue and allow for the large amount of growth planned in the South-west Christchurch area. These investigations are planned to be complete by mid-2008. The works are currently planned for construction from 2010 to 2012. These works are currently shown on the Major Sewer Upgrade map as "Halswell Pressure Main Stage 2", which is one of the options being investigated.

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Disclaimer: The routes, time and cost mentioned for the major sewer upgrade projects that have not begun or finished construction are estimated only. They are still subject to change as deemed necessary by the Christchurch City Council.