Clevedon businessman Jay Bath told the Herald he had lost 18 animals, worth between $18,000 to $20,000, in the floods.
"A friend has rung in tears, saying they can see livestock floating down the river."
He said one farmer had lost a good number of his 2000 sheep as the rising flood waters "wiped out" low lying paddocks.
Grant Henson told Newstalk ZB he woke to hear the sheep, which were on his property, drowning.
"I could see a big pile of them cuddling up on one 3m by 3m little bit of dry land, all piled up like a pile of puppies. I can some bodies floating around."
Hanson, his wife and four children are being rescued by boats making their way up the swollen Wairoa River.
Bath said the flooding was "by far the worst [it] has ever been".
"Our whole family is heartbroken, the animals that we've cared for, and hand-reared lie dead below 2m of water, waiting for us to collect them when the water resides," Bath said.
"Everywhere you look it's just water, it's never been this bad in 22 to 25 years. I know people who have been here for 50 years and they've never seen it this bad here before."
He said farmers, wearing lifejackets, were wading into the flood waters in a desperate bid to save their remaining stock.
Kay Hinds, who lives on North Rd near Clevedon, said the Wairoa River was so flooded it appeared to be part of the Hauraki Gulf.
"The river is huge, it's just like the sea," she told the Herald overlooking the river from her hilltop home.
She lost two horses to the flood waters, and she could see her neighbours' stock floating down the river.
"My daughter rang me and said, 'it's horrible hearing the cows crying and sheep crying as they are being washed down the river'."
She said it was the worst flood she had seen in the 24 years she'd lived in the area.
"I've never seen flooding like this. The rain was torrential last night, I've never heard anything like it.
"It's going to get worse," she said, expecting the about 4pm high tide to cause more damage.
