Nelson mayor Aldo Micchio says preparation work is underway on land that slipped during a major storm two weeks ago as heavy rain is predicted to hit on Thursday.
MetService says a low pressure system is expected to bring wet weather and there may be heavy rainfall in the Nelson area and northern parts of the North Island.
Mr Micchio says more heavy rain is the last thing the region needs.
He says if any resident believes their house is at risk of slips they should evacuate the property.
Mr Micchio is advising people to clear gutters and drains so water can flow easily into the storm water system.
He says contractors will be working hard to ensure unstable land has good drainage before the predicted heavy rain.
The Mayor of the Tasman District, Richard Kempthorne, says people still dealing with slips are the ones most worried about the prospect of more rain.
He says those people should ring the council recovery line for advice on how to deal with another downpour.
In mid-December the Nelson-Tasman region suffered its worst storm in 50 years.
A state of emergency declared after the two-day storm flooded roads, caused more than 50 slips and damaged nearly 150 homes was lifted on Tuesday afternoon.
MetService forecaster Paul Mallinson says rain will arrive in the top of the North Island on Wednesday, spreading over the north west of the North Island and to Nelson and Marlborough on Thursday
"That continues until Friday so there's going to be a significant amount of rain for those northern parts of the North Island and in Nelson."
On Friday, the rain will hit the Coromandel Peninsula, Bay of Plenty, Wellington, Buller, and parts of Marlborough.
Mr Mallinson says the rainfall in Nelson will not be as bad as two weeks ago.