Clevedon residents are reporting huge stock losses as the town east of Auckland is hit by the worst floods in a generation.
Local farmers and residents have spent the day saving what animals they could, but know when the waters eventually recede the full toll of the floods will be revealed.
Resident Kay Hinds said there were ongoing efforts to rescue stranded stock, but there was "not a lot of high ground" available.
Clevedon businessman Jay Bath told the Herald he had lost 18 animals, worth between $18,000 and $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 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 see some bodies floating around."
Henson, 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.
"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.
Bath also raised concerns about the possibility of overflow at nearby dams flooding low-lying fields and killing stock.
However, Watercare Services said the water storage dams in the nearby Hunua Ranges were weathering the storm well.
"The water storage dams in the Hunua Ranges are operating as normal, despite over 240mm of rain falling within the past 24 hours," water supply manager Priyan Perera said.
He said the water levels in the dams rose significantly overnight, with Cosseys and Hays Creek dams now full and spilling.
"Cosseys Dam rose 17 per cent as a result of this rainfall and is now spilling.
"When our dams reach capacity, they are designed to spill into an engineered spillway. When this occurs, the volume of water being released is simply reflecting the flows through the natural environment."
He was aware some local residents are concerned water was actively being released from the Hunua dams, resulting in downstream flooding.
"This is most certainly not the case. Unlike hydroelectric dams, our dams do not have release gates - as a water supplier, our aim is to store as much water as possible.
"The four large dams were not full prior to this event, meaning they have been able to capture and contain a lot of the water - minimising the scale of potential flooding downstream."
He said the storm has not compromised the structural integrity of the dams.
The high volume of rain has also affected the clarity of the water in the dams, and Perera said the change in water quality will require Watercare to carefully manage the incoming flows and treatment processes at Ardmore Water Treatment Plant.
Kay Hinds, who lives on North Rd near Clevedon, earlier 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 looking at the river from her hilltop home.
She knew of two horses lost 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 high tide about 4pm to cause more damage.
Auckland Transport is providing regular updates about road closures on its Facebook page.