A Tukituki River mouth blockage has flooded several properties in Haumoana forcing the evacuation of residents in sunny weather.
Residents were evacuated about 2pm on Friday as high tide approached.
Garages on three properties were flooded but no homes reportedly went under water.
Hawke's Bay Regional Council confirmed water levels were going down by mid-afternoon and "will continue to drop off with the lower tide".
Hastings District councillor Ann Redstone said the Tukituki River mouth being blocked wasn't unusual.
"It does get blocked because of heavy rain when shingle gets pushed back into the river mouth, but we have had heavy seas as well," she said.
"The water is only at the sheds but not inside the houses to my understanding."
She said about four homes were impacted.
"Just the ones which back onto the drain, which drains down into the Tukituki."
A Haumoana resident, who did not want to be named, who lives on Haumoana Rd, said he had been living in the area for more than two years and it was the worst flooding he had seen in the area.
He said the water had impacted properties between 1 and 7 Haumoana Rd - where properties were positioned quite low to sea level.
He said the flooding had left lawns under water and flooded sheds.
He said the regional council were in charge of clearing out the mouth of Tukituki River to prevent flooding on nearby properties, but they appeared to have left it "just too late this time".
Hawke's Bay Regional Council regional asset manager Martina Groves said they assessed the river mouth on Friday morning about 8.30am.
"The Tukituki River was flowing high, and the river mouth was open," she said.
Council confirmed they began work clearing the river mouth about 12.30pm to prevent flooding.
"Although [the river mouth was] still open, the force of the swell caused water to back-up into Grange Creek and subsequent flooding into the garages of three properties."
She said the river level began dropping about 2pm after council had worked to clear the river mouth.
"Additional river water still coming down from Red Bridge is not expected to cause any significant additional level rise at Grange Creek.
"The level will continue to drop off with the lower tide, and will only rise again slightly with the next high tide."
A Haumoana resident who did not want to be named said she called Hawke's Bay Regional Council on Friday morning to warn them of a potential flood because the Tukituki River mouth was blocked and water was banking up.
"I had been out for a walk on the Black Bridge walkway and when I turned around to come home I had to wade through the water to get through.
"You just knew at that point that the tide was still on its way in and there was going to be trouble.
"I rung the regional council and spoke to a guy who was dealing with floods in Wairoa as well. He was quite dismissive and basically just said to me 'You do know it's a flood plain, right?'."
The woman said it was time the council did something to plan for blockages better, and it needed to listen to residents.
"Locals know this area better than anyone and it's been happening for far too long."
Further north in Wairoa, heavy rain throughout the day caused the Wairoa River to break its bank, along Kopu Rd.
Heavy rainfall overnight on Friday saw some areas of the district receive between 90mm and 100mm over a 24-hour period.
Wairoa District Council chief executive officer Kitea Tipuna said the Wairoa District has a "huge catchment", and within a 4200sq km area there is more than 3000km of rivers and tributaries which all flow into the Wairoa River.
"By around lunchtime on Friday there was in excess of three million litres per second flowing under the Wairoa Bridge and out to sea," Tipuna said.
"The river level is very high, particularly along Kopu Rd, and the river mouth is open and flowing.
"There is a considerable amount of surface flooding, and the roads are slippery and wet. We urge whanau to stay home and stay safe."
Council staff and contractors were on high alert and monitoring the situation.
There were some localised slips and one road, Waiatai Valley Rd, closed due to flooding.
Heavy rainfall in the Wairoa township over the past 48 hours also resulted in significant infiltration of stormwater into the wastewater network.
Tipuna said the community have been asked to reduce their household wastewater such as baths, showers and toilets where possible.
"Council has utilised the provisions provided under s330 of the RMA to allow for a limited discharge of treated wastewater outside the conditions of its current resource consent. Utilising this provision allows council to safely manage the location, timing and volumes of treated discharges in line with river and tidal conditions."
MetService had a heavy rain warning for the Wairoa District in place from 8am to 4pm on Friday.
The warning stated that a further 50mm to 70mm of rain was expected to accumulate on top of what has already fallen.
The council said on Friday morning that Waiatai Rd was closed due to flooding, and warned road users there were also a few slips down, and surface flooding in places.
Meteorologist Tui McInnes said rain was expected to gradually ease as the day progressed.
"But the same trend is set to continue tomorrow, in terms of it being a wet day, but it will be because of intermittent showers," McInnes said.
"Hawke's Bay is the most exposed to the current low pressure system, making it the wettest region."
In the last 24 hours 76.6mm of rain had fallen over Wairoa, 50.4mm in Napier and 26.8mm in Hastings, he said.
"Wairoa is the wettest part of New Zealand at the moment, because it is quite exposed."
Showers were expected to ease overnight on Friday but a wet, damp day was forecast for Saturday.
"Winds turn from south to north on Sunday and it's expected to be drier on Sunday, but it will be wet again on Monday."
With another front coming through at the start of next week, brief periods of rain were expected.
Temperatures were expected to stay between 11C and 13C, with overnight lows expected to be between 2C and 5C until Monday.
The Hawke's Bay Regional Council monitors 38 tele metered rainfall recording stations throughout the region, almost all having had more than 30mm of rain since Thursday morning.
Many north of Napier, from Te Pohue to the Urewera National Park, had more than 90mm.
South of Napier, and into the Kaweka and Ruahine ranges, some had also had more than 90mm, and most had more than 30mm, but at Crownthorpe, said to be almost the driest place in Hawke's Bay after below-average rainfall in almost every month in the past two years, there had been just 27mm in about 40 hours.
The heaviest on Friday was the 105mm at Waipoapoa in Central Hawke's Bay, and the heaviest on Friday to mid-afternoon was the 74mm at Pukeorapa, inland from Nuhaka, with other recordings of over 60mm at Urewera park headquarters Aniwaniwa, Marumaru's Wairoa River station, and at Kotemaori.
In coastal areas, Waipatiki had had about 94mm and Waimarama about 76mm.
To the south, 57mm had been recorded at Mangaorapa in Southern Hawke's Bay.
Around the twin cities, 38mm had been recorded in the Napier CBD, and 31mm at Bridge Pa.