Civil Defence is making preparations for the return of thousands of people to Christchurch over the next few weeks, following last month's major aftershock.
It says an estimated 60,000 people have left the city since the quake.
Civil Defence National Controller, John Hamilton, says the situation in Christchurch is much better than two weeks ago, but it's not as rosy as some people might be expecting.
He says the sewerage system is still unstable, so if locals are offered a chemical toilet they should take one.
Mr Hamilton says there will be a total of 19,000 portaloos and chemical toilets in the city by the end of the week.
He says returning residents need to be careful when turning on power and must remember to boil water.
The power company, Orion, says excluding the central business district, 550 households are still without power in the city.
Police say there has been an increase in alcohol-related crime in the city, with 29 arrests made on Saturday night.