A section of Lighthouse Road and the surrounding land is experiencing instability following a significant wet weather event from 30 April to 1 May 2025.

Sign up to our Lighthouse Road land instability newsletter

What happened

Christchurch City and Banks Peninsula experienced prolonged, intense rainfall between 30 April and 2 May 2025, resulting in flooding and multiple landslides across the region.

On Thursday 1 May, significant cracking was found along Lighthouse Road and the surrounding land. The road was closed late that night, and affected residents were evacuated as a precaution.

Preliminary geotechnical assessments were carried out and used to establish primary and secondary zones downslope of the land instability area that could potentially be affected by debris flow if the land moved further. Monitoring equipment was also installed on Lighthouse Road to give regular information about land movement.

Monitoring equipment has been installed on Lighthouse Road to give regular information about land movement and further geotechnical investigations are ongoing to better understand the situation, our options and plan our next steps.

In an emergency, where there's an immediate risk to life or property, call 111.

We have received a draft geotechnical report, carried out by independent geotechnical engineers Engeo, outlining information obtained from the borehole drilling completed onsite during July 2025. This data has provided a better technical understanding of what is going on deep underground.

Based on the data, the geotechnical experts no longer believe the primary and secondary areas are considered at risk from debris.

The revised understanding is that a release of any debris is unlikely to occur as it would need to be significantly larger than the May 2025 event. Even if debris was released following land movement, it is no longer considered a risk that it would reach properties in the primary and secondary areas.

This is because of what we now know about the land. If any debris were to release, the volume would be at the lower end of what was previously modelled and isn’t expected to flow easily due to the makeup of the land, which has a high clay content.

The change in risk profile based on the new technical data means the portaboom installed to restrict public access on Lighthouse Road will be removed. This is scheduled to happen by 15 August 2025, following our contractor carrying out minor repairs needed following the borehole drilling. 

The change in risk profile also means the primary and secondary zones near the land instability that were put in place following the State of Emergency are no longer required. We no longer see properties in these zones as being at risk of debris flow. The land instability area remains, with two properties (land only) affected.

Monitoring equipment installed on Lighthouse Road will remain in place to give regular information about the land and any movement. Lighthouse Road is expected to remain open unless the monitoring data indicates a change in risk. To date there has been no significant movement since the severe weather event between 30 April – 2 May 2025.

What’s next?

We are still looking at what potential remediation measures are required to protect Lighthouse Road and help minimise risk to the property immediately below the land instability site.

A Council report, which will reference the finalised geotechnical report, is scheduled to go to the next Finance and Performance Committee Meeting on 27 August 2025 for elected members to consider and provide direction on.

Need support?

If you or someone you know requires immediate welfare assistance, please email our community support team.

We’re committed to keeping you informed.

For updates, sign up for our newsletter(external link) or email lighthouseroad@ccc.govt.nz.

To speak to our staff, phone 03 941 8999 or 0800 800 169.