Skip to main content
Start of main content

Cross Harbour Pipeline Investigations

Investigating an underwater pipeline to withstand a major earthquake and keep delivering Wellington’s water supply

  • 700

    Routes Investigated

  • $4m

    Project Fee

  • 17km

    Estimated Length of Pipeline

  • Wellington, New Zealand

    Wellington, New Zealand

How do we keep the water flowing in a Wellington earthquake?

New Zealand’s capital lies between two great tectonic plates and sits atop one of the most active geological faults: the Wellington Fault.

The city’s water supply relies on pipelines that cross the Fault in several locations. In a major earthquake these pipelines are expected to sustain significant damage, resulting in extensive parts of Wellington going without water for up to 100 days.

When it was discovered that the Harbour Bores project was unviable, we investigated ‘Plan B’: the Cross Harbour Pipeline (CHP). If progressed, this solution would significantly improve the disaster and operational resilience of Wellington’s water supply by providing an alternative pipeline route that doesn’t cross the Fault and is designed to remain in service after a one in 2,500-year earthquake.

Because the CHP would be located within a seismically active environment, there is still a risk of damage from other natural hazards once it's built. To quantify these effects an innovative design approach was required that involved significant geotechnical work and assessment of over 700 pipeline routes to select the most resilient route and design. We had the best people on the job and the majority NZ-based design team were joined by international experts from the UK, Los Angeles, and Calgary in Canada.

At a Glance

Offices
Client
  • Wellington Water
Partners
  • GNS Science

We're better together

  • Become a client

    Partner with us today to change how tomorrow looks. You’re exactly what’s needed to help us make it happen in your community.

    Contact Us
  • Design your career

    Work with passionate people who are experts in their field. Our teams love what they do and are driven by how their work makes an impact on the communities they serve.

    Join the Team
End of main content
To top