More damage: The remains of a damaged house at Shag Rock (Getty : Martin Hunter)
The New Zealand government says yesterday's powerful aftershocks in Christchurch have not set back the city's recovery effort.
Fourteen tremors shook the city overnight - with the strongest a 4.7-magnitude quake at about 2:45am - but there are no new reports of damage.
Yesterday's first aftershock, measured at magnitude 5.5, sent people running into the streets in the middle of the day, and was followed an hour-and-a-half later by a magnitude 6.0 quake.
The quakes further damaged buildings in the CBD and caused more silting and flooding, particularly in the eastern suburbs.
But earthquake recovery minister Gerry Brownlee says the damage may help speed up decisions on which areas and buildings are to be rebuilt.
"I think it's just confirmed that the areas damaged on the event of February 22 have become more damaged," he said.
"I think yesterday's events will help everybody make their decisions a little more quickly."
Mr Brownlee says he thinks one of the reasons there was no loss of life yesterday was that many old and dangerous buildings have already been destroyed.
"As we stand here, in a big wide space, you can look around in all directions and see that there are vacant lots or buildings partly under demolition," he said.
The minister says thousands of households are likely to be told they cannot rebuild on their land.
Many roads and bridges around the city remain closed and an estimated 20,000 people are still without power.
Water has been restored to 90 per cent of the region but people are being told to use it conservatively.