Parts of the North Island could be badly flooded if a storm expected on Tuesday is as strong as forecast.
Up to 160mm of rain is expected in Coromandel, Bay of Plenty and Gisborne.
Some 100mm is predicted to fall in Northland, where the ground is saturated.
Northland Regional Council says the ground in the region is already saturated, and river levels are still high. It says flooding is likely to be more extensive, and more intense, than at the weekend, causing more slips and road closures.
The storm is expected to arrive from 3pm on Tuesday.
Meanwhile, it's hoped about 200 Auckland customers who were left without power at the weekend will be reconnected on Tuesday.
However, the Vector lines company says there could be further outages and people should prepare for that.