Authorities are concerned that some flood-affected farmers in Southland are not asking for help.
The state of emergency, which includes Fiordland, has been extended until Tuesday 18 February.
The decision was made by at a joint committee meeting, says Emergency Management Southland controller Angus McKay.
Members of all the local councils and other emergency services partners were at the meeting.
“We are still assessing the impact of the floodwaters in many areas in Southland and we have parts of Fiordland that are closed and need to remain so,” says McKay.
A co-ordinated response led by Civil Defence in Southland is still needed at this stage.
“We are working hard to plan the recovery phase and that will happen in due course.”
Southland and parts of Otago were flooded after a bout of heavy rain last week.