The Ministry of Civil Defence will work with councils to change tsunami plans after a new report found parts of New Zealand could be struck by bigger waves than previously thought.
A report by GNS Science found a powerful earthquake off the New Zealand coast could cause 15 metre waves in some areas, which could arrive before official warnings are issued.
Civil Defence director John Hamilton told Morning Report the new information will require changes to disaster planning.
He said an earthquake big enough to cause a major tsunami strikes New Zealand only once in 2500 years on average, but a damaging wave happens every 40 to 50 years.