The advice from Auckland Emergency Management to Aucklanders is for people to act immediately if they see rising water, due to how quickly flooding can happen.
They say anyone who sees rising water should not wait for official warnings.
They should evacuate to high ground and stay away from floodwater.
Evacuation Centres are available to those who need somewhere to shelter.
The agency also has directed Aucklanders not to travel unless necessary and to check road conditions before travelling if travel cannot be avoided.
And the numbers to call for help:
111 in case of emergency
Auckland Emergency Management - 0800 22 22 00
Waka Kotahi urges road travellers to check conditions on their journey planner website - www.journey.nzta.govt.nz
The Ministry of Social Development has set up a support line - 0800 400 100 - which is open from 8am.
