Bay of Plenty regional council says the Whakatāne River has reached its highest level since 2019, but its flood defences will be able to cope with the rain.
Slips have come down in heavy rain in central Bay of Plenty, isolating at least three communities - Rūātoki, Awahau and Tāneatua.
MetService has lifted a heavy rain watch that was in place from Rotorua to Te Kaha earlier on Wednesday.
All residents of the Rūātoki area connected to the council supply are on a boil water notice.
Whakatāne Civil Defence duty controller Nicholas Woodley said because roads into the Rūātoki valley were still impassable, council staff could not get to the water treatment plant to do the testing that it needed to.
That was why it had issued a precautionary boil water notice, he said.
Rūatoki tribal authority chair Patrick McGarvey said the community was used to wild weather, and was resilient.
The flooding had isolated people in the Owhakatoro community in the Urawera ranges, but they were sending in supplies to help, he said.
Woodley said there were issues earlier on Wednesday with Whakatāne residents told to minimise use of their wastewater systems, but that had eased as the rainfall today was not as heavy as it had been.
The Whakatāne River level came up overnight but by Wednesday afternoon was dropping, he said.
It was expected to peak by early Wednesday evening.
Motorists urged to take care
Woodley said that people should take extra caution when driving in the region.
"We've got a number of slips and other roads that have surface flooding, and there are slips continuing to come down as well in some parts of the district, so we are just recommending people to drive with caution and just to be aware that they may encounter these things on the roads unexpectedly."
There are number of roads in the district where slips are continuing to come down, he said.
Waka Kotahi is asking people in Eastern Bay of Plenty to restrict unnecessary travel.
Regional system manager Roger Brady said those travelling risked hurting themselves and others.
State Highway 2 which has been blocked by slips would be assessed early on Thursday morning for further damage, Brady said.
Woodley said no areas had been evacuated, but that people could leave themselves to stay with relatives or contact the council if they had nowhere to go and they were concerned for their safety.
Waimana has been cut off due to slips and Te Urewera ward councillor Andrew Iles said its residents could not access basic supplies because their local shop owner could not get into the town.
"Road access has been cut and left Waimana basically isolated, you usually hear traffic roaring through the main street and behind me you hear the traffic on the other side of the river roaring along State Highway 2 - but there's a deadly hush [on this side]."
Waimana Gorge State Highway 2 is expected to remain closed overnight.
The Bay of Plenty Regional Council's update at 2pm on Wednesday said the Lower Kaituna and Whakatāne / Tauranga Rivers were at warning level two. It said that meant that the river was higher than normal and had started to spill into the area next to the river, but was still within the floodway or stopbanks on either side.
Heavy rain warnings in place in both North and South Islands
MetService said the rain in Northland could ramp up later on Thursday, and into Friday.
Northland is under an orange level heavy rain warning with up to 130mm of rain expected to fall before 3pm on Thursday.
It said heavy rain may cause rivers and streams to rise rapidly and cause surface flooding and slips.
MetService said its predictions show weather warnings in Taranaki may be upgraded in the coming days.
This snapshot of the Rain Radar at 6pm is a good summary of the areas set to get the most rainfall over the coming days— MetService (@MetService) May 3, 2023
Far northern and western parts of the North and South Islands are ones to watch, with lesser amounts elsewhere
See the latest info at https://t.co/qHyE5zzql5 pic.twitter.com/My0i3eYGTQ
Many regions were under an orange heavy rain warning - including the top of the North Island, Wellington, and Westland - but Taranaki was more likely to see its orange warning upgraded, it said.
MetService meteorologist Mmathapelo Makgabutlane said Taranaki was likely to get more rain, being in the line for the trough to be stalling nearby.
Rain was predicted to ramp up in Taranaki early on Thursday morning, she said.
In the South Island, West Coast Civil Defence said staff were closely monitoring the bad weather but the impact has been minor so far.
Severe rain warnings and watches are in place for much of the South Island's West Coast for Wednesday night.
Civil Defence said it was largely a wait-and-see situation, and staff were on stand-by in case things got worse.
There would be a regional Emergency Management meeting on Friday to go over the latest forecast, and have a plan in place in case bad weather continues into next week, it said.
A heavy rain warning is also in place for Marlborough north of the Wairau Valley, Nelson and parts of Tasman with up to 300mm of rain forecast from 9pm Thursday through to 3pm on Saturday.
Fire and Emergency NZ monitoring situation
Fire and Emergency New Zealand said it was closely monitoring the weather warnings across the country to work out where to send additional resources - if they were needed.
In a statement, deputy national commander Brendan Nally said Fire and Emergency was being proactive in making early preparations.
"Northland is already seeing some impacts of heavy rain, so we have sent resources, including some of our USAR capability to Kaikohe in Northland," he said.
Further deployments would be considered for other locations as Fire and Emergency received more certainty on the weather modelling and conditions on the ground, Nally said.
"Our focus is on supporting our communities, some of which have already been affected by previous events this year, most notably Cyclone Gabrielle," he said.