Torrential rain leaves roads closed after flooding and slips

The weather has eased in North Island regions hit by torrential rainfall on Tuesday and overnight, but thunderstorms are today forecast for the west coast and bottom of the North Island and the top of the South.

MetService said Gisborne had the most rain overnight, with 132mm over the Raukumaras, and in Whakatāne reached close to forecast levels with almost 50mm falling.

Fire and Emergency's on-call commander for Tamaki Makaurau Brad Mosby said they received 300 callouts across Auckland on Wednesday, but only 60 overnight.

There had been some minor slips that impacted properties, but no one was hurt in those events, he said.

Auckland Emergency Management deputy controller Rachel Kelleher said emergency services had coped well with the storm overnight.

Auckland Council received 39 service requests, two of which were for flooding in houses, she said.

Firefighters received 10 calls for help, mainly in the upper North Island, including a vehicle stuck in floodwaters.

The overnight downpours came after heavy rain and thunderstorms battered parts of the North Island on Tuesday.

A local state of emergency was declared in the country's largest city as flooding quickly occurred once again after heavy storms in January and Cyclone Gabrielle in February.

MetService forecasts North Island showers, thunderstorms in west

Weather warnings for Auckland and Bay of Plenty have expired, but the rain is expected to continue at least until Thursday.

MetService said 116mm of rain fell in West Auckland on Tuesday, most of it during the period between 10am and 12pm.

Yesterday's rain was not as heavy nor persistent as it was in the January floods, MetService said.

On 27 January, some parts of the city saw 250mm in just 24 hours.

While there is some relief from extreme weather events for the North Island today, in the south there are several heavy snow watches in place for later today.

The MetService said a thunderstorm near the Cook Strait was likely to affect people on both sides.

The forecaster has a thunderstorm watch in place for Kāpiti-Horowhenua, Wellington and Marlborough. The storms are accompanied by torrential rain.

MetService meteorologist Georgia Griffiths said most of the rain eased from Auckland, Northland and right through to Bay of Plenty overnight.

"As expected Bay of Plenty had a rough night, we had multiple thunderstorm warnings there yesterday evening, with 40 to 50 millimetres of rain recorded in just one hour."

Everywhere across the coastal zone from Tauranga to Ōpōtiki saw downpours of 35mm an hour on Tuesday night, she said.

"And as you've seen across Northland and Auckland and also the Bay of Plenty soils were completely sodden before we got those downpours and torrential rain rates, it was never going to do anything but flood."

It had cleared now and MetService currently did not have any severe weather warnings or watches in place for the North Island, she said.

The western North Island including Taranaki down to Kāpiti Coast could expect frequent showers with a north-west changing to south-westerly today which would lead to a temperature drop, she said.

There were a lot of thunderstorms around Taranaki this morning and they had short sharp rainfalls but were over quite quickly, she said.

A tornado struck South Taranaki early on Wednesday morning ripping off part of the roofs of two houses.

Bay of Plenty, Northland and Auckland could still see some short sharp showers but it would be nothing like Tuesday, she said.

Auckland commuters struggled to get home during Wednesday's torrential rain with congested roads, cancelled trains and long queues for buses.

Auckland Transport said making sure commuters could get home in an emergency was still a work in progress and it would look to prioritise bus lanes in future.

Roading

State Highway 1 from Auckland to Northland has reopened in both directions.

Coromandel Civil Defence teams have been out and about on Wednesday morning assessing any damage.

Thames Valley Civil Defence Controller Garry Towler said there were numerous slips and debris about but they were glad all roads were open. But many were down to one lane or under stop-go, he added.

State Highway 3 in King Country was closed due to an under-slip on the road on Wednesday afternoon.

The road is closed in the Awakino Gorge, south of the intersection with Awakau Road.

In Northland, a body was recovered during the search for a Year 11 student from Whangārei Boys' High School missing in the Abbey Caves network after their group called to be rescued in heavy rain on Tuesday morning.

Torrential rain hit the Bay of Plenty on Tuesday, with Rotorua recording more than 65mm between 3pm and 5pm.

Bay of Plenty Civil Defence duty group controller Cara Gordon said thunderstorms had a severe impact on the Tauranga and Western Bay Area on Tuesday, causing surface flooding, slips and road closures.

There were closures on SH2 Tauranga to Katikati, northbound, and 36 Tauranga to Ngongotaha due to flooding.

Hamurana Road, between Mourea and Unsworth Road, and Edmund Road between Nairn Road and Homedale Road were closed.

Pukatahi Bridge on State Highway 2 in Eastern Bay of Plenty has been closed for safety reasons after rising river levels.

Waka Kotahi said the Whakatane River is about 600mm below the bridge deck and it would stay closed until the water-level dropped.

Detours are in place that will add approximately 10 minutes to travel times.

In Nelson, heavy rain has caused 150 metres of Montrose Drive to subside in the suburb of Atawhai.

Nelson City Council said the subsidence did not affect homes and no evacuations were required. A blocked culvert on Montrose Drive that was causing high stormwater flows had since been cleared, it said.

A number of roads have remained closed in the city following heavy rain in the region.

Parts of Aniseed Valley Road and Maitai Valley Road are closed, with Clouston Terrace, Atmore Terrace, Māori Pa Road and Cable Bay Road restricted to resident access only.

In Marlborough, Bothams Bend Road, Omaka Ford, Jackson Ford and Wairau Bar Road are closed and motorists are advised to drive with caution after heavy rain caused surface flooding overnight.

A severe thunderstorm watch remains in place for the region with downpours of up to 35mm an hour possible.

All sports parks and several reserves throughout the region are also closed.

Lisa Glass from Emergency Management Bay of Plenty said a lot of people would be waking up to surface flooding around their property and there were isolated cases where people needed to be rescued.

But she said they were relatively lucky and although some people may have left their homes to stay with relatives due to flooding, no official evacuation centres needed to be set up.

The orange heavy rain warning for Bay of Plenty including Rotorua had been in place until 3am on Wednesday.

Here's your early morning Radar map

Some thunderstorms and lightning around, which will be in the mix today

Keep a close eye on the forecast at https://t.co/Yjbq0jgaoz pic.twitter.com/QtqU1j0IOf

— MetService (@MetService) May 9, 2023

Rotorua Mayor Tania Tapsell said the weather had improved this morning but the problem with heavy rainfall at the moment was that the ground was already completely saturated.

"So we do see a higher risk of flooding and especially surface flooding which did close many of our roads."

Workers were out checking about 50 locations, mostly around streams, she said.

Streams and drains were not able to drain the way they normally would because the Rotorua lake levels were incredibly high due to the city receiving so much rain this year, she said.

"Our crews have been working hard overnight to ensure that any trees, any slips and also assessing the roads where the water has completely covered it, making sure that those are safe for people to get to work and go about their day today," she said.

Surface flooding would be the biggest issue today, she said.

"Fortunately now all we're looking at is a bit of a clean-up job with a few slips but many trees down too."

Acting Auckland Mayor Desley Simpson said rapid response teams would be assessing 100-130 properties due to the rainfall from Tuesday and overnight.

They would also assess the land and other properties around those places to make sure it was not wider than the initial assessment, she said.

Anyone who wanted an assessment undertaken should contact Auckland Council at RBAComms@AucklandCouncil.govt.nz

Simpson thanked Aucklanders for their patience as they navigated some tricky conditions to get home last night.

She said it was unlikely to be the last time that Auckland would see this type of flooding situation and it was the fifth flood this year.

Climate change meant New Zealand seemed to be seeing far more of this tropical type of weather that had traditionally been seen in the Pacific Islands, she said.

Thunderstorms hit Nelson, Marlborough Sounds, snow forecast for Passes

In the South Island, the MetService warned severe thunderstorms were hitting Nelson and Marlborough Sounds on Wednesday morning.

The thunder was accompanied by torrential rain which could make driving conditions hazardous or lead to flash flooding, it said.

The National Emergency Management Agency advises that as storms approach you should take shelter indoors away from window, avoid sheltering under trees if outside, clear gutterings and secure any loose objects around your property and be ready to stop or slow down if driving.

MetService was warning of snow on South Island roads later in the day.

Snow was expected on Lindis Pass, Lewis Pass and Arthur's Pass from 5pm and for the Milford Road from 4pm.

Griffiths advised motorists who intended to travel over the Passes to check in with MetService or Waka Kotahi / Transport Agency to check the snow situation.