Sixty-five flood damaged homes in the Westport area have been red stickered.
West Coast Emergency Management said it has been able to assess about 90 percent of the more than 2000 affected properties.
Just over 300 have been yellow stickered and about 1800 have no or only slight damage.
Work is under way to ensure people who cannot go home have somewhere to stay and emergency accommodation options are being looked at.
Buller District Mayor Jamie Cleine told Checkpoint it looked like about 100 people would be continuing to stay in welfare centres tonight.
He said there are houses in Westport that have been flooded multiple times.
"You need to step back and think is there additional flood protection measures that could be done or is there just parts of the town that should be retreated from, that's a discussion for another day not today."
One-stop shop for flood-hit residents
A one-stop shop for residents will be open from 8am-4pm at the NBS Theatre in Westport until Sunday.
Local controller Te Aroha Cooke said it will allow affected residents to register their needs and get information.
The community hub will host a range of agencies including Buller District Council, Age Concern and Red Cross.
It is expected that representatives from Kainga Ora, the Ministry of Social Development and Animal Welfare will be available at the hub later this week.
A drop-in health clinic is open at 51 Russell St, Westport this week from 11.30am until 4.30pm.
All Covid-19 vaccinations have been cancelled this week in Westport, while scheduled medical appointments have been postponed.
There is a temporary medical ward at Club Buller and it will remain operational throughout the week, but the Buller hospital is expected to be out of action for at least a week. Club Buller is being used for low-risk patients from the hospital.
Evacuation centres are still operating at Westport South School, the Salvation Army, the Carters Beach Holiday Park and the Kiwi Holiday Park in Westport for residents unable to return to their homes.
West Coast Emergency Management is warning residents returning to flood damaged houses to seek advice from Buller Electricity or a registered electrician.
Flood damaged homes have been disconnected by Buller Electricity until residents can ensure it is safe to electrically reconnect.
Supermarkets have experienced high demand for water but there are no other supply concerns.
Residents are advised to use personal protective equipment (PPE) if they handle items which have been in contact with flood water. All flood water should be treated as if it has been contaminated, West Coast Emergency Management said.