About 200 Napier residents were evacuated from a school, campground and homes in a riverside settlement north of the city early this morning.
People returning to Eskdale Holiday Park this afternoon found it strewn with debris, mud and silt.
Campground resident Arthur Yarnold was woken at 6.30am with a warning the Esk River was about to breach its banks.
"So we sort of started to organise ourselves and waited a little while but we could see it creeping up and creeping up and then when it got probably just before this levee bank, we decided to evacuate."
His neighbour, Bailey Salter, said he did not realise how bad the situation was until the camp manager stopped him on his way out for the day and told him to go back and pack up.
"It wasn't until I got back to my caravan that I looked at the river and it was just about to burst its banks.
"So we just went round and packed up everyone's caravans and we'd just finished mine when it burst that bank and it got from there to here in about 20 minutes."
The force of the waist-high water moved trees and debris throughout the campground, even picking up and flinging a cabin against the fence-line, he said.
The last time this campground was flooded was when Cyclone Bola hit - exactly 30 years ago today in what remains the country's most devastating and costly storm.
The campground owner, Daniel Gale, who was six-years-old at the time of Bola, said this was much more rapid.
"It's never flooded since [Bola] - this is way different.
"This happened over 12 hours, Bola took three days ... It's going to take a while to clean up, that's for sure."
A boarding school just up the road, Hukarere Girls College, also chose to leave this morning, as did some residents in the Esk Valley area and in Patoka.
More than 60 students from Havelock North Intermediate were also evacuated from their school camp in Rissington.
Principal Julia Beaumont said they were sleeping in tents.
"Everything was all good until about midnight when the rain really picked up. So this morning, with the worsening weather, the teachers just decided it was time to come home."
People living near the Esk River catchment were tonight being advised to prepare to leave if necessary, with more heavy rainfall forecast tonight and tomorrow.
A Metservice forecaster, Tom Adams, said the heaviest rainfalls so far had been inland in central Hawke's Bay due to a very slow moving front bringing thunderstorms.
"There's a station near Glengarry, which has seen over 322mm of rain in the last 24 hours and the vast bulk of that has been this morning."
Steve Wheeler's property alongside the Esk River was quickly flooded by the heavy rain.
"It was almost as if the thunderstorm had basically parked itself over the top of the Esk Valley and just let rip.
"So by 11am the water had come right up, much higher.
"So yeah, it covered the paddocks and it started to head up to one of the neighbours houses - it was right up to her back doorstep," he said.
The flood waters have hit vineyards in the Esk Valley, several areas of grapes were flooded this morning to a depth of about 20cm.
Angela Ranson from Linden Estate winery said there could be a problem for this year's output.
"If we get too much more water the grapes will probably split and then there is the possibility of losing the crop," she said.
"The winemaker is not too bothered at the moment because some of the crops with high acid should be OK, but some of the crops might suffer.
"Some of the whites will probably be okay because they have got a bit more acid but the Syrah might not cope so well.
"However, all that remains to be seen."
Nearby in the rural town of Rissington, 18 houses were left without power after a tree fell onto power lines.
As much as 90mm more rain was forecast to fall before 1am tomorrow.
However, Hawke's Bay Emergency Management head Ian McDonald said it was unlikely to cause further major problems "unless it all comes at once".
"We've had some properties flooded - I'm aware of at least two or three - at the moment we're phoning all the properties in the inundation area and finding out where they're at in terms of their properties and what help they need."