Fire and Emergency said three homes were evacuated in Nūhaka due to flooding and people were relocated to a local marae. Crews helped pump water out of at least one of those houses.
FENZ assisted two drivers stuck in floodwaters on State Highway 2 and one house in Māhia threatened by flooding.
State Highway 2 was closed between Whirinaki and Gisborne and SH38 was closed from Wairoa to Waikaremoana.
"A very wet night last night across that area there, some spots as much as 120mm of rainfall in just 12 hours or so - really intense bursts of rain, but over a prolonged period as well," MetService meteorologist John Law told Morning Report.
Some parts received between 15 and 30mm of rain an hour for five hours in a row.
"It really was a huge amount of rainfall."
Hawke's Bay Civil Defence said trees had come down and flood debris was causing hazards on the roads. It advised drivers to delay travel if possible.
An evacuation centre has been opened at the Wairoa War Memorial Hall and at Tanenuiarangi Marae in Nūhaka.
Law said the narrow band of rain was moving north, and the worst was over.
"There is still a bit of rough sea around the coastal parts, but things are getting much better in that sense. So it is an improving story. The heaviest rainfall is pulling away as we go through the next hour or so."
Wairoa District Mayor Craig Little said the Wairoa River level was high but it had not breached its banks.
"Which is good, and it shouldn't now because we're going out to a low tide," he told Morning Report.
"But a lot of surface flooding out of Nūhaka around the Frasertown area… with that amount of rain, you just can't get it away quick enough."
"People probably don't need this" - Wairoa District Mayor Craig Little duration4′ :23″
Nūhaka School in Wairoa - currently operating out of a chapel, after its school grounds were evacuated - was closed for the day because of the flooding and road closures.
"It's pretty hard on those children to go through this trauma again," Little said.
Principal Raelene McFarlane said it had been a rough night, and her thoughts were with people in Nuhaka and Wairoa who had been affected by the flooding.
Wairoa Primary School was set to open, with a spokesperson saying they were waiting for further instruction from the Ministry of Education.
"People probably don't need this," Little said. "[There's] still a bit of rain anxiety… they worry about what's going to happen again in terms of any flooding… it's just not what we need."
Little said locals should not plan on going anywhere on Wednesday, and keep up to date by visiting the Wairoa District Council website and listening to updates on the radio.
A MetService orange heavy rain warning was in place for the Wairoa district to 7am, while Tai Rāiwhiti/Gisborne south of Tokomaru Bay had a heavy rain watch through to 8am.
