Three families have been evacuated by helicopter in the Nelson region as flood waters threatened their properties.
Detective Senior Sergeant Ian Langdridge says more heavy rain is predicted in the hours ahead so the Operations base and Tasman District Council are closely monitoring river levels.
He says three families were airlifted to safety and a further ten families have been temporarily re-housed.
Between 10 and 20 homes in the Tapawera area are now considered to be isolated by floodwaters in the Nelson region. River banks are only just holding out and there is a lot of flooding.
Nelson Civil Defence spokeswoman Penny Bloomberg says roads are completely blocked between the Twin bridges on Baton Valley Road, and at Mcleans reserve in the Motueka Valley due to a large slip. She says the Red Cross is now operating in the Tapawera Township providing support to people affected.