Earthquake Recovery Minister Gerry Brownlee says he's received reports that land damage in Friday's earthquakes in Christchurch is about 30% or 40% of damage that occurred in an aftershock in June.
Mr Brownlee travelled to Christchurch on Friday afternoon to assess the situation as the region suffered a new round of substantial earthquakes.
He said suburbs of Christchurch that have already been red-zoned suffered the worst in the strong aftershocks on Friday, but it was too early to tell if whether more land will need to be red zoned and written off.
Mr Brownlee said the city's infrastructure has been largely unaffected. The sewerage and water systems had not been damaged and public transport was still running.
Over the coming days, geotechnical engineers will be assess the extent of the damage
Mr Brownlee said his calls for damaged, historic buildings in Christchurch to be demolished have been vindicated.
"I've been saying right from the very beginning of this - and I got huge criticism for it - saying get these buildings down.
It's only the fact that we've had some of these areas so heavily cordoned off ... that we haven't seen a more disastrous day today."
Prime Minister John Key said his heart goes out to the people of Christchurch and Canterbury.
Mr Key said it will be a frightening and disheartening time for residents but they can be confident the authorities are onto the situation and Government resources stand ready to assist wherever needed.
