Kaikoura has less than 24 hours of drinking water left, while vital supplies are also diminishing.
However, Civil Defence says restoring water supplies and ensuring bottled water is flown into town remains their top priority as many people remain homeless from Monday morning's earthquake.
Over three tonnes of water was already flown in to Kaikoura today.
Kaikoura Mayor Winston Gray also reassured tourists that it was also their mission to get them evacuated as quickly as possible.
Of the approximate 4,500 people in town, about 1,000 were tourists, he said.
Of that, about 85 per cent - or 850 - were international and he was well aware of their travel commitments.
As at 1pm today, 160 had been flown out by helicopter. Numbers had been boosted by the arrival of an army helicopter which could seat six instead of the usual three.
Gray said it would be Saturday - at its best bet - before they could reopen Inland Rd which cuts down to Waiau toward Hanmer.
Then they will convoy about 50 vehicles at a time. He estimated there were up to 400 vehicles left in Kaikoura.
Civil Defence controller John Mackie said they would spend today assessing the damage. Extra specialist engineers had arrived and others were en route to help out.
Sorting water was his mission.
"Clean, fresh drinking water. There's about a day's storage left."
As for locals sleeping in cars or at friends, they could be helped by USAR crews who could fix minor plumbing, electrical or structural repairs.
Another goal was to set up water drinking stations around town.
Gray said he felt for farmers. The 23 dairy farms in the region were having to use generators, however council staff were yet to properly assess the impact on beef and dairy farmers, he said.
He hoped to get to a few farms tomorrow.
More portaloos were also on the way.
Council chief executive Angela Oosthuizen said the quake had proven a challenge for council as it was the country's smallest, next to the Chatham Islands.
The head of civil defence said tonight that over three tonnes of water was airlifted in to Kaikoura today, and more would be brought in tomorrow.
Sarah Stuart-Black, the director of the Ministry of Civil Defence and Emergency Management, said the Fire Service also had also set up a desalination plant in the wake of Monday morning's 7.5 earthquake.
She said phone services had been improved in Kaikoura as well with cellphone access, although there could be pockets without coverage.
"Food, water and fuel are required in Kaikoura, Hurunui and Marlborough and we are co-ordinating relief supplies to ensure that those essentials are getting to the people who need them the most."
"Three and a half tonnes of water was airlifted in, with more planned tomorrow," she said at a briefing in the Beehive bunker this evening.
She said staff from local civil defence and emergency management groups in Kaikoura, Hurunui and Marlborough would be going door to door at night to check on households.
Earlier today a state of emergency was declared across the Canterbury region to mobilise the collective force of the region.
"This supersedes the states of local emergency in Kaikoura and Hurunui."