Steady rain in South Canterbury and North Otago has flooded dozens of roads and prompted travel warnings.
Waitaki Civil Defence says 50 to 60mm of rain has fallen in coastal areas on Wednesday and more is expected in the evening.
The rain comes on top of heavy rains in the area a week ago that caused widespread flooding.
The Transport Agency says there is surface flooding on State Highway 1 between Pareora and Glenavy and inland on State Highway 83 from Pukeuri to Duntroon.
At least 18 rural roads in South Canterbury and North Otago are closed because of surface flooding.
Timaru district Civil Defence says 20 other roads have impassable fords, and 23 are seriously flooded.
It is warning travellers to take extreme care, and to avoid unnecessary travel.
Further north, the Transport Agency is also warning of surface flooding on State Highway 1 between Kaikoura and Blenheim.
Meanwhile, Canterbury regional council says the region's river flood protection works have withstood nearly twenty-four hours of constant heavy rain.
The rain has caused flooding in South Canterbury, with many roads in the region closed.
But its rivers are handling the latest downpour well.
The council says that between 40mm to 50mm of rain has fallen in coastal and foothills areas since late Tuesday night.
