The lengthening road to recovery

Cyclone Gabrielle devastated the rural roading network in the eastern part of Masterton District. Reporter FLYNN NICHOLLS joined council roading engineer Alec Birch for an inspection from Blairlogie to Mataikona to survey the damage.

When Cyclone Gabrielle hit on February 14, many Masterton roads – especially on the eastern side of the district – were inundated by flooding, debris, slips, and washouts.

Masterton District Council [MDC] maintains 800km of roads spread throughout the district’s 2300 square km of land, and about a quarter of that land was seriously damaged in the storm.

The immediate roading response cost an estimated $1.35 million, and the final cost is expected to be millions more.

Slips as far as the eye can see, looking back over the Tinui hills from the top of Pakowai-Tinui Rd, which connects Tinui Valley and Mataikona. PHOTO/FLYNN NICHOLLS

Flooding cut off homes and entire communities, putting pressure on roadworkers to get everything back on track.

Thanks to a dedicated roading response, only four houses were still cut off four days after the cyclone.

But more than a month on, the council’s rural roading engineer Alec Birch said there was still a lot of work to do.

“Tinui was a terrible mess, but we had a big initial response to open the roads.

“It wasn’t just us; every local with a tractor or a digger got out and cut their way back toward the contractors,” he said.

Birch is one of five engineers on the council’s roading team.

He oversees the rural roads – 400km sealed and 300km unsealed – keeping an eye on the crews of contractors who carry out a schedule of routine resurfacing and pavement strengthening, working section by section through the network.

Birch initially trained as a draughtsman with the Ministry of Works but has been working on roads since 1995, most of that time with MDC.

While four crews of contractors would normally be doing renewals for the whole district, after Gabrielle there were 10 crews just between Blairlogie and Tinui.

Birch was out and about, keeping an eye on the contractors and crews.

“Each storm is an individual, but this has been the worst 12 months I can remember.

“We’ve had two cyclones and three other flood events,” he said.

The section of Masterton-Castlepoint Rd between Balirlogie and Manapakeha contains some of the most difficult engineering problems in the district.

The road is filled with slips from above, dropouts from below, and washouts, where a river or debris has taken out the road from beneath.

The first stop on our inspection was to talk to a crew doing slope strengthening work where an entire hillside was sliding into the river, bringing the road with it.

Pointing at the slipping hillside, Birch said he had seen a report from 1975 that said the Masterton-Castlepoint Rd had been destroying roading engineers’ reputations for four generations.

“That was almost 50 years ago, and look where we are now,” he said.

Digger operator Mike Leonard said his crew had dug down more than 6m and then put concrete reinforcement pillars 13m beneath the road surface.

The next step would be placing alternating layers of mesh covers and compacted dirt 500mm apart all the way to the road surface.

The section had started to slump a year ago, but Birch said once it started, the best thing to do was wait for it to develop.

“With stuff like this, you just have to wait and let the earth do the moving for you, then you can go back and do the strengthening work,” he said.

Birch noted that the geology was not good for road building.

“This land is made of rubbish, and it’s been aggravated by the storm,” he said.

He said that the western side of Masterton district was much sturdier due to its rocky greywacke terrain, while the eastern side was “crumbly, faulted sedimentary mudstone”.

“If you look at a geological map of this area, it’s horrible: it’s all broken up and severely faulted.”

Greater Wellington Regional Council has spent decades planting the area with willows and poplars, famous for their capacity to suck up water and hold soil.

Birch said the land had mostly stayed put where the hillsides had been planted for strengthening.

“In the 1970s, before there was any forestry or planting here, the carnage on the hillsides was amazing.

“From an ecological point of view, you would never cut down the trees here for pasture. It’s historically unstable land,” Birch said.

“In some cases, the best thing to do, from a roading perspective, would be to retire it and plant it, but you can’t tell a private landowner what to do with their land.”

Beside the Whareama River, council droving yards from the days before livestock trucks were being filled with truckload after truckload of silt dug up from road drains and paddocks across the district.

In Tinui, flooding buried the whole plain under a sheet of mud, water, and debris.

We saw digger operators slowly digging silt out of long stretches of filled roadside drains, sending truckloads back to the droving yards for dumping.

Birch said it would be months of slow work.

“The people who live on the land understand; they’re patient with us; they know it will take a while. But some people, they say to us, ‘We want to go to the beach, these council roads are in a state’, and then they want to hang you.”

Further into Tinui Valley, huge amounts of wood, vegetation, and mud debris lined the sides of waterways, bridges, and roads.

“The truth is, we don’t even have enough road cones for all the hazards on this road,” Birch said.

“I can’t get a set of temporary traffic lights for love or money, and all it takes is one machine to pack up or one worker to not show up to throw the schedule out by weeks.”

Given the scale of the damage, Birch recommended that drivers slowed down and kept their eyes open.

“On a rural road you should always expect the unexpected.”

We drove up the remote dirt path from Tinui Valley to Mataikona, called Pakowai Tinui Rd, in the far northeast corner of Masterton District.

On the hilltop we got out of the ute to look at the view, surveying the vast Tinui landscape and bearing witness to the scale of the destruction.

Every hillside as far as the eye could see was streaked with light brown marks, slips from the cyclone.

Our last stop was Mataikona, one of the most remote and least populated parts of the Masterton district.

We passed a private swing bridge that was destroyed by trees coming down the Mataikona River.

Its steel wires were tangled up with wood across the riverbed.

Just past it, a large chunk of the road had been washed out, leaving a hole in a cliff face above the river.

Birch estimated a proper repair would cost over $1 million, but the council had opted to fence it off and make a makeshift path around the hole.

“We can’t keep fixing this stuff. The damage is too frequent, and the area is so remote.”

Beyond the river mouth, 15km of Matatikona’s coast road is under constant threat from the ocean.

Birch said that 6m swells had battered the already damaged section during the cyclone.

“It’s crumbling into the sea; the waves will just keep battering away at it forever.

“With all these roads, it’s a battle against the elements, always was, always will be – never delude yourself otherwise.”

Despite the problems, Birch was confident the damage could be repaired.

“We have months of work in front of us, but we’ve got it under control.”