UPDATED 11.30am

It's taking longer than expected to get Wellington's Ngaio Gorge open to traffic again.

A large slip came down in the early hours of this morning, and contractors have been working to get it cleared.

Council spokesman Richard MacLean is hoping the road will be useable again by about mid-afternoon.

"Please try and avoid the area and take alternative routes because apparently the traffic's pretty bad around there," he said.

Wellington residents who have been evacuated due to slip fears are in limbo as officials carry out safety assessments.

A group of students from a house on Evans Bay Parade have spent the night with friends and family amid safety concerns.

Meanwhile, a family on Devon Street in the Aro Valley has been forced from their home after a slip tore out the sewage connection.

Wellington City Council welfare manager Jenny Rains says there have been dozens of slips throughout the region, and people should always be prepared to evacuate at short notice.

There have been more than 460 slips across the Wellington region this winter, amid repeated waves of heavy rain, according to Civil Defence.