Cyclone Gabrielle – one year on ...

In one of the worst-hit areas, houses are filled to the rafters with silt. Lank weeds grow in what were once peoples’ bedrooms, kitchens, and bathrooms. We pass former vineyards, some still bent under the weight of silt; others now cleared and replanted in neat rows of maize. 

The wind is up today. Silty little dust devils whir across the valley, past houses washed off their foundations. Faded signs from Urban Search and Rescue are still visible on the walls of some – painting a grim reminder that lives were lost last February.

Harry recalls WSP’s survey of the cyclone’s aftermath. He and colleagues made it only a few kilometres up Esk Valley before striking a washout that prevented further access.

“We were driving on flooded roads, forced to weave around obstacles. There was mud and debris everywhere. In some places, silt and water on the road was half-a-metre-deep.

“Roads were blocked. We had closed the Napier Expressway due to the amount of water. We couldn’t get past the Esk turn off to access State Highways 2 or 5. To the South, State Highway 51 was closed. We couldn’t pass Awatoto. Several local roads and bridges had gone. Napier was completely isolated. It was like a war zone,” he says.

The force of the water stripped fill away from many bridge approaches, scouring out around the abutments. Some bridges were cleaved in two and submerged by the furious waters.

Harry takes us on State Highway 2, Napier - Wairoa Road. A big project is underway at Devil’s Elbow, where traffic is down to a single lane. The tight hairpin bend was almost completely washed away. An immense WSP-designed retaining wall is being built - soon expected to be ready.

On the way back to Napier we pass roadside sensors and rain gauges. Installed by WSP, they’re part of proactive work to monitor slope movement. With climate change resulting in more frequent and intense downpours, this kind of kit is becoming increasingly necessary in much of the country.

Harry points out a culvert that stood up well to the cyclone’s hammering. It had been damaged and repaired years earlier, after Cyclone Bola in 1988. Bola was intense too, says Harry - although its rainfall was spread out over three days, not the few catastrophic hours it took Cyclone Gabrielle to dump its moisture.

One year on, the impacts of the storm – one of the deadliest and most destructive to ever hit New Zealand – are still fresh in peoples’ minds. After conducting bridge surveys and inspections for over thirty years, Harry has never seen destruction as severe as that caused by Cyclone Gabrielle. He hopes never to again.

In Napier, as in other parts of the East Coast, inspections and emergency repairs started immediately. In the first days and weeks WSP engineers hit the road checking the soundness of bridges and assessing landslips.

Work group manager for bridges and structures Natalia Uran tells us about a colour-coded GIS system WSP put in place to triage the inspection of over 1,000 East Coast bridges.

“Green bridges had some defects but could remain open; orange had to either go down to a single lane or have weight restrictions; red had to be closed.”

About fifteen bridges were lost in Napier. One of the first big projects was a temporary bailey bridge in Waikerie Gorge on the Napier – Wairoa Road. Cyclone Gabrielle had left the old bridge a twisted hulk of concrete and steel - cutting the East Coast in half. 

A collective team involving WSP, Downer, Higgins, and NZTA Waka Kotahi worked wonders installing this and other temporary bridges across the East Coast, Bay of Plenty, Coromandel, and Auckland. Since then, engineers, including from WSP, have been helping put things to rights as part of a Transport Rebuild East Coast (TREC) Alliance that’s been set up to plan, organise, and deliver much of the recovery and rebuild work needed on the region’s state highways.

Gisborne too took the brunt of Cyclone Gabrielle, causing widespread flooding, and wiping out critical infrastructure. In the six weeks after the cyclone WSP inspected 600 bridges and structures in Gisborne. Eighty bridges are still being worked on that need some form of repair.

The small settlement of Te Karaka was especially badly affected. It tragically lost a community member to the floodwaters. People had to self-evacuate and were left stranded for over 24 hours. 110 houses were claimed by the water.

An impressive community-led recovery effort is underway in Te Karaka, involving temporary housing, house lifts, emergency planning, and psychological first aid training.

WSP Gisborne’s Peter Carlyle, whose property was badly damaged in the cyclone, says his local river is coming up a lot quicker now in smaller rain events.

“We recently had 150 millimetres of rain, which is not a big burst for here and it was almost back up to where it started spilling over back in February. So, rain anxiety is a bit of a thing now - knowing that the rivers aren't coping as well as they used to.”

We meet Gisborne Mayor Rehette Stoltz in WSP’s Gisborne office the day after our tour of Esk Valley. She says it’s important to build back for the long term, in a resilient way. It’s a view echoed by the engineering community.

“The two major pou (pillars) of our recovery are roading infrastructure and flood protection. The work will be ongoing for the next five to ten years. It’s important we repair and rebuild well, once, so we don't have to go back and fix up after every event.

“Let's have that longer term view- especially on State Highway 2 and State Highway 35. Let's make sure that resilience is built with the work we do there.

“We need the support of companies like WSP to walk alongside us in this very tough time, so that at the end we can look back and say, ‘we made our kids and moko (grandchildren) proud with the decisions we made in this recovery time’”.

Reflecting on Cyclone Gabrielle one year on, it's heartening to see how business and communities have come together on recovery efforts. While scars and memories of the devastation persist, we're hopeful that the experience will help build a stronger, more prepared infrastructure future – ready for what storms may come.