Western Hills Sewer Main Rehabilitation

At this stage, the scope of this project is for the urgent renewal of a 590m wastewater pipeline which is jointly owned by Hutt City Council and Upper Hutt City Council that is in poor condition. 
 
This is the main pipeline serving approximately 50,000 people including Western Hills in Lower Hutt and Upper Hutt. 

• Primary objective: Providing reliable services to customers. 
• Secondary goal: Minimising public health risks associated with wastewater and stormwater.

There are no indications of imminent failure with the pipe and we’re regularly monitoring its condition.  

• In the short term, we have a contingency plan in place to ensure we’re keeping the disruptions to a minimum if a pipe failure occurs prior to the repair. 
• And in the longer term, we have a preferred option to rehabilitate the pipeline that will minimise transportation disruption on SH2.

If a pipe failure occurs before the repair, there may be some environmental and transportational impacts depending on the failure and the effectiveness of our operational response.

We’ll be working closely with Hutt City Council, Upper Hutt City Council, Greater Wellington Regional Council and NZTA to determine the best approach. We will communicate with the public to ensure they are aware of the approach, timelines, and any impacts of the work. 

We have funding for the initial investigations and options assessment which is now underway. Further funding for the next phases of works will be informed by the initial assessment and worked through with our council owners in due course.  

The project is currently in the design phase, and we expect to carry out the rehabilitation work in 2025.

This finding further highlights the ageing infrastructure in the Wellington region and the importance of our existing programme of work for condition assessment our council owners fund us to do which support the prioritisation of pipe repairs and renewals throughout the region.

In this case, the condition assessment has identified that the pipe is in worse condition than anticipated, so has enabled repairs to be developed prior to the assets failing.