A state of emergency has been declared for the Otorohanga District in the Waikato - which has been inundated with widespread flooding and slips overnight

Mayor Rodney Dow made the declaration just before 1 o'clock this morning - saying the situation is serious - and it's important the right controls are in place to prepare for any evacuations if needed.

He's urging residents to stay home and not venture out into floodwaters.

Heavy rain warnings remain in force for Coromandel Peninsula, Bay of Plenty and Tairawhiti - lapsing between nine this morning and eight tonight.

State Highway 39 in Waikato is also closed between Otorohanga and Pirongia due to flooding.