A man's still missing after being washed away in his car trying to cross Mahurangi River near Warkworth - north of Auckland

Police say a passenger escaped the vehicle and raised the alarm.

An urgent search is under way, with a section of Falls Road closed.

Orange heavy rain warnings span Auckland, Great Barrier Island, Gisborne District south of Tolaga Bay, Hawke's Bay, and Tasman west of Mapua.

Rodney Local Board member Ivan Wagstaff says drivers should stay off the roads - especially near rivers.

He says a lot of the roads will become impassable if the weather worsens.