Eight homes have been evacuated in Kaikoura after heavy rain loosened debris from a cliff.
The local council says the evacuation is a precautionary measure and residents have been taken to the Top 10 Holiday Park.
Kaikoura is still recovering after the 7.8 magnitude earthquake struck the region on Monday.
Nikki McLean who has a 9 week old baby has had to evacuate her Kaikoura home due to the risk of a cliff collapsing behind her home. pic.twitter.com/VKDKdErdrh— Conan Young (@ConanYoung1) November 17, 2016
Nikki McLean - one of the evacuated residents - said she had just got her house in order after Monday's quakes when she had to flee with her young family.
Ms McLean and her partner have moved to a holiday camp with their 9-week-old daughter and 3-year-old son.
She said they were given half an hour to get out.
"We had just got the house in order, because it was raining yesterday, and it was the first time we could clean the floors and vacuum up all the glass - we'd not long had power on - heat up water for a bath and everything, so it was a bit like 'oh no, you're joking'."
Ms McLean said she hoped to get news this morning that she could move back home.
Civil Defence director Sarah Stuart-Black said some houses at risk of flooding, because of water building up behind the slips, have also been advised to evacuated.
"There have been reports of multiple landslides blocking streams or river valleys particularly in remote and rugged areas of inland and seaward Kaikoura ranges.
"We urge people in those areas to be especially vigilant and to keep clear of river valleys and outlets.
"Landslide dams can break quickly and release large volumes of water and sediment as a flood wave."
View RNZ's full coverage of the earthquakes here
A convoy of 27 Defence Force trucks carrying vital supplies for Kaikoura was stuck overnight 80km away, but is now moving again. They have water, fuel, enough fresh food to feed 250 people over the next week, and a team of chefs to prepare the food.
The earthquake caused significant damage to the landscape and made the town inaccessible by road or rail, trapping thousands of tourists and residents.
The coastal route of State Highway 1 was blocked both north and south of Kaikoura by massive slips.
The convoy left Christchurch late yesterday morning but did not get further than Culverden last night.
The convoy got back under way this morning, with the trucks given clearance to continue on to Kaikoura.
They're on the way # kaikoura pic.twitter.com/ELEnVUs2uE— Sally Murphy (@Selbellnz) November 17, 2016
Mayor Winston Gray said he did not have an estimate of exactly how many people were without water.
But he said the number was likely to be growing as water stored in undamaged parts of the network ran out.
Work to repair broken water pipes has been hampered by the difficulty in accessing materials and parts.
The navy ship Canterbury has anchored 600 metres off the Kaikoura coast, and choppy seas meant helicopters were needed to transfer 500 kilogram loads to land.
Warships from Australia, Canada and the United States - with about 660 sailors and four helicopters between them - are assisting in the relief efforts.
Commander Simon Rooke said coordination between the ships had been easy.
"We all speak the same language, that's why we exercise together whenever we can, so that when things like this happen, the procedures and the commonality already exist. So yes, it's a lot of moving parts, but it's quite effective and smooth-running, because we all understand how everybody does business."
Cdr Rooke said 18-person work parties were heading to shore to help the clean up.
The government is not ruling out providing support packages for larger business affected by the quake.
The subsidy package announced yesterday is limited to small businesses with 20 or fewer staff for up to eight weeks.
Businesses in Kaikoura, Cheviot, Waiau, Rotherham, Mt Lyford and Ward are eligible and those in Marlborough, Picton and Blenheim will be considered next.
Economic Development Minister Steven Joyce said small businesses were the priority at this stage because larger businesses were better equipped to sustain themselves.
He said the package will be reviewed in the lead-up to Christmas.