The Earthquake Commission says thousands of complex flat land claims in Canterbury will take longer than normal to settle.
The agency says it hopes all flat land claims will be assessed by the end of this year, with payments starting to be made now.
But it also says there are about 14,000 complex shared land claims, such as cross-lease titles. These settlements will be delayed.
EQC land settlement head Zac Berry said surveys and drilling have also identified two new types of non-visible land damage.
These are an increased risk of flooding due to subsidence, and a higher risk of liquefaction in another earthquake event.
Mr Berry said analysing the complex data from surveys and drilling means the timeframe for these settlements is also uncertain.
The EQC also said some claims from the Port Hills were difficult as homeowners share retaining walls, although all these claims have been assessed, and should be paid by the end of the year.
But Carmel Jaggar, a spokesperson for a group of residents, said the delays will only add to the home owners' stress and she's surprised issues like these were not foreseen far earlier.
She asked why work was not done sooner to simplify settlements for properties where there are cross-lease agreements.