People living or holidaying in low-lying areas of Coromandel Peninsula are being asked to evacuate.

The Defence Force has already been sent to the district, and four Unimogs are expected to arrive before 10am.

All communities in Coromandel could be affected by the remnants of Cyclone Cook, which are bearing down on New Zealand today, Thames Valley Civil Defence controller Garry Towler said today.

"Whangamata has been hammered since dawn," he said in a video posted to the Thames-Coromandel District Council Facebook page, adding there had been "substantial flooding" to residential areas in the town.


Mercury Bay and Whitianga had "coastal issues".

"We're asking for people to bear with us until midday [when] we get a better assessment of where we're at," he said.

Once people begin to evacuate, Civil Defence would be able to reassess the situation, Towler said, and it would "give us a picture of how many vulnerable situations we have on the peninsula".

Many had already chosen to evacuate, he said, and Civil Defence had helped 50 caravans and motorhomes to leave the area.

Civil Defence centres would open at 10am for evacuated residents and anyone who feels unsafe. "Staff there will look after them."

The Defence Force had already arrived in the Coromandel peninsula, Towler said, and the Unimogs would be sent to vulnerable areas.