Roading crews seem to have been busier than ever since the start of 2023, with storms and cyclones wreaking havoc on the country's state highways.

Slip after slip, crack after crack – storm damage and road closures are becoming business as usual for many state highways across Aotearoa.

Waka Kotahi's Bay of Plenty and Waikato maintenance and operations manager Rob Campbell says it's a "big challenge" keeping the network running.

"We've got a very large programme of maintenance and operational works going on all of the time and that keeps us very, very busy. And then add on to that things like the cyclones coming through, storms, events that happen on the highway [like] accidents."

When one of these storms hits, Waka Kotahi's central north island maintenance and operations manager Jaclyn Hankin says the first task is to "make sure everyone is safe".

"Then in the background, the people who don't have to be out there on the roads get on calls and start making a plan, understanding where we're at."

They get their intel from several sources to build that picture: contractors, the public, councils and civil defence.

"Then we try and get a road open as quickly as we can," Campbell continues.

"You do almost a quick and dirty job initially – get the access open and allow people through."

Then it's all about figuring out the cause of the problem and what the fix should be.

Waka Kotahi staff don't do the mahi on the roads – that's the role of the contractors. Ben Buttimore is one of these, managing the Coromandel storm recovery for Higgins.

"It's two steps forward, one step back at the moment...it can become demoralising, literally, I mean it's a colloquial term but it's a rinse and repeat cycle," he tells The Detail.

His teams are fixing a slip near Opoutere, on the eastern side of the Coromandel Peninsula, which came down during Cyclone Gabrielle.

"There was a very large landslip down the bank, it probably projected well over 50 metres into the bottom of the valley. That encompassed the entirety of the north and southbound lanes," Buttimore says.

His teams have had to build a large retaining wall to get the road back open again, albeit with just one lane open to traffic, controlled by traffic lights.

State Highway 25A, the road that connects the two Coromandel coasts, has been damaged even more significantly.

The road won't be open again until some time next year, because a bridge needs to be built.

Campbell says the bridge was "the best of some not great options quite frankly".

"In this case, we always described it as, you can build back up, you can go over, or you can go round," Campbell says.

"We needed to look at all those three options in some detail to understand which one's going to be the one that allows us to get access back through there as quickly as we could.

"Before you build anything that substantial, you need to be building off good foundations and footings so we needed to do an awful lot of work to understand where is the good material...what we found in that whole area is there's not a whole lot of good material anywhere. On the road corridor itself we found rock about 30 metres below the bottom of the slip, which is 20 metres below where the road was."

He says that gave Waka Kotahi certainty the bridge was the best option, plus it was actually the fastest.

With storms constantly wrecking highways across the country, Campbell says the government's asked Waka Kotahi to start looking at climate adaptation.

"That plan is by around 2035 to have established a different way of working, a new way of looking at this, to be building things differently – to be looking at where we need to maybe retreat from rising sea levels or managing high rainfall differently."

It'd help answer questions such as whether some roads are built in the right place.

"Those are very expensive options obviously, you can't do that everywhere. So then it's how do you make sure that the culverts are big enough, the bridges are strong enough, that we've protected the abutments to the bridges so they don't wash out, so you're adapting the type of infrastructure you have."

Buttimore is seeing the change now right before his eyes, calling it the worst he's seen it in his 20 years in the industry.

"Higgins as the lead contractor for Waka Kotahi had to rebuild the Thames coast after a huge storm event in January 2018. While that was a massive project – and a huge undertaking and really did stress and strain the Coromandel communities – we didn't lose a key route like we have with State Highway 25A, a route just didn't disappear. That was one large event, not three major storm events within one month of January alone, with preceding storm events in November and December, followed up by a whole raft of events through April, May and June.

"It's just this constant run of weather related things – in a boxing analogy you're sitting there and the blows just keep coming, you just make sure that you are blocking and reacting and counterpunching as best you can."

Hear more about what it takes to get roads back open in the full podcast episode.

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-Tom Kitchin/RNZ.