Storms, flooding and slips have inflicted serious damage on farms in central Hawke's Bay.
Large areas of low-lying farmland were been flooded in the two-day storm; one station near Waipawa recorded 500mm of rain.
Marion McKee, who with her husband farms 610 hectares near the coast at Blackhead, said up to three-quarters of the property has been lost to slips and other damage, and their immediate neighbours had been hit just as badly.
Another coastal farmer, John Nation, said 530mm of rain in two days had caused deep slips on hillsides, destroyed fences, including boundary fences, and damaged buildings.
Mr Nation estimated about half his farm has been destroyed in the storm.
Another farmer reported damage to almost all fences and the loss of a dam.
With precious grass gone, affected farmers say they will need to reduce stock numbers.
Federated Farmers, which is collating information about the damage, says initial reports indicate that farms in a narrow band inland from coastal Hawke's Bay have been hardest hit, and there will also be stock losses.
Hawke's Bay president Kevin Mitchell says some coastal properties have lost more than half of their pasture.
Once it has assessed the level of damage, the organisation will be working with the Rural Support Trust, councils and other bodies to get help to those who need it.