Ōamaru Wastewater Pipe Renewal Project - 2026 - 2030

Relining a wastewater pipe is possible when the pipe is in a good enough condition.

The pipework is cleaned, and any root intrusion is cleared away. A pipe insert is then pushed through the pipework, forming a new, solid, sealed pipe within the old pipe after being cured.

The benefits of relining are that trench work, digging down to replace pipes, is not needed, and this can be done with minimal disruption.

Relining can extend a wastewater pipe's lifespan by between 50 and 60 years.

Sometimes it is not possible to replace a wastewater pipe. This can be for a few reasons, including;

• Damaged or collapsed pipework, beyond the ability of remote repair or relining
• Old configuration of pipework - e.g right angled pipework - which cannot be relined

In this case, trenching work is required - either to replace the entire pipe, or effect replacement of the collapsed section.

When some of our wastewater pipes were installed, they were designed for the population of the time and some growth.

Nearly a century later, some of these pipes need replacing with larger diameter pipes to manage both the growth since 1928 and to allow for future growth in our District.

This will involve trench digging along the pipes to be replaced, up to depths of 4 metres below the ground. 

In the Oamaru Wastewater Pipe Renewal Project, there is one confirmed site where this will be required - the Cross St, Severn St, Coquet Street. This pipe receives all of the wastewater from Holmes Hill, Waiareka Junction and Weston.

This work is likely to take place early in 2026, as Waitaki District Council wants to get the wastewater pipe network renewed before NZTA resurfaces State Highway 1.

Severn Street Upgrade - 778 metres

The replacement of the Cross Street, Severn Street, Coquet Street pipework will increase the pipe diameter in this section. This is to account for the growth of Holmes Hill, Waiareka Junction and Weston in the last century, and allow for future growth in these areas.

Thames Highway Pipe Renewal - 2093 metres

This renewal work will involve earthenware pipework that runs between Orwell Street and Ribble Street, either side of Thames Highway, with some sections crossing the highway, and some parts of Ouse, Trent and Torridge Street.

The Reed Street package involves renewing pipework between Torridge Street and Cross Street and renewing pipework on Coquet Street from Reed Street to Thames Highway.

This pipework is 1928 earthenware and will be investigated to determine whether it can be relined or needs replacing. This work will also be timed to align with road rehabilitation work, meaning the pipework gets renewed before the surface is relaid.

There is a 369 metre section of 1928 earthenware wastewater pipework on Greta Street which requires renewing.

Whether this is by relining or replacement will depend on investigation, but work needs to happen on this section of the network.

CBD - Rear of shops and Historic Precinct

Good news! There are no wastewater pipes running the length Lower Thames Street. All of the properties between Coquet Street and Itchen Street are served by 1928 earthenware wastewater pipes located behind the shops, either feeding out to Severn Street, or to Humber Street.

There is also some pipework running between Tees and Tyne Street, and from Harbour Street to Tyne Street that requires renewal.

These pipes will require investigation to determine if they will be relined or replaced.

The pink lines indicate the wastewater pipes that are part of this package.

South Hill 

There are eight sections of 1928 earthenware pipe on South Hill which do not align with the road network and run across property boundaries. As they were installed a century ago, they also follow original boundary lines before further subdivision and development.

This pipework will need to be investigated to determine if they will be relined, replaced or require new solutions.

The areas in yellow below indicate the pipes in this package.

In 2026, Waitaki District Council will begin replacing, relining or upgrading around 9km of its 1928 earthenware wastewater pipe network. As this project goes to tender, contractors may wish to visually inspect parts of the pipe network - including sections that are on private property.

We have identified four packages of work, and details about them and maps of the areas the work will be happening in are available on this page.

The pipework being replaced, relined or upgraded are those identified as requiring our urgent attention.

No. At this point potential contractors will be assessing the network visually. If any work is required on your property, you will be contacted by Council or our contractors well before it is due to take place.

The wastewater network is gravity fed, and for South Hill in particular, the pipework follows land contours - and 1928 boundary lines. There's been a lot of growth and subdivision since then, but the pipework still follows the gravity feed path to take what you flush away.

This webpage outlines the packages of work, and explains the process of relining, replacing or upgrading pipework.

You can also contact Council by emailing service@waitaki.govt.nz