Floodwater is covering large parts of the eastern Bay of Plenty after 24 hours of heavy rain.
Ōpōtiki dairy farmer Dean Petersen said 80 percent of his farm was covered in floodwater following 200mm of rain.
Locals have reported that several large rivers appear to have burst their banks.
Ōpōtiki District Council said the Ōtara River, which runs through the town, has recorded its highest-ever level.
The council has activated its emergency operations centre and put portaloos out because the town's wastewater system has broken down.
Mr Petersen farms on the banks of the swollen Ōtara and Waiotahe rivers, and said floodwaters are covering most of his land.
"On one of the properties the regional council had done some river protection work and had just finished, and floodwater has breached that again and its come into our land.
"We haven't had this for three or four years now ... you've just got to deal with it when it happens."
On one farm most of the floodwater was tidal, and high tide is at 6am this morning, Mr Petersen said.
"Hopefully it drops at low tide and we'll be able to start getting rid of some of the floodwater ... as long as you get it (water) off quick enough within 48 hours.
"If it's left on much longer the pasture starts rotting. It's been quite a dirty flood so there'll be lot of silt on the ground"
Power is on at the three properties, but one farm is cut off by floodwater, he said.
"We were talking to Fonterra last night about whether we can get in there to get the milk out ... that'll be the next problem."