Liquefaction explained

Liquefaction happens when saturated soil loses strength during earthquake shaking, behaving like a liquid. Auckland’s mapping shows where soils are more vulnerable based on geology and groundwater conditions. It is regional data, not a foundation investigation for your specific house.

Liquefaction vulnerability

Council mapping identifies areas with soils that may liquefy or settle unevenly in a significant earthquake. This is most relevant on reclaimed land, estuary edges, former wetlands, and some coastal flats across Auckland.

• Foundation design and retrofit costs can be higher in vulnerable zones
• Insurance and EQC cover have changed over time; check current rules with your insurer
• Building consent may require geotechnical input on some sites

If liquefaction mapping appears at your pin, treat it as a flag to investigate further before purchase, especially for older homes on flat land near the coast or harbour. A geotechnical engineer can assess your specific section.