TREC Tairāwhiti recovery update

Issue 34

14 November 2025

Tēnā koe

In this edition, read about work to protect the Rotokautuku (Waiapu) Bridge near Ruatoria, new culverts going in to help protect State Highway 35 (SH35) at Rototahe from flooding, and check out how the willow wall at the Kemps Hill (SH35) site is growing.

There's updates on some of our State Highway 2 (SH2) projects and we’ve also included a reminder to drive with care through work sites, following some recent risky behaviour.

Thanks again for your support and patience as we carry out this important recovery mahi.

SH2 Hakanui Straight project flood resilience - 2 lanes reopening this month

Good news for drivers: from 21 November, SH2 through the Hakanui Straight project will reopen to 2 lanes, reducing delays.

This section has been down to one lane while crews installed culverts (large pipes) and built up the area around the highway.

The upcoming traffic switch will move vehicles onto a newly raised section, allowing work to begin on lifting the existing highway - a key step in boosting flood resilience.

The work is weather dependent, and dates may change if needed.

What to expect:

• One-lane traffic 24/7 from 17 November to prepare for the traffic switch
• Two lanes open from 21 November (weather permitting)
• 30km/h speed limit and traffic management still in place
• Further traffic switches and changes ahead as crews continue raising the road and work through to April 2026.

Thanks for your patience and for driving safely through the site. We’re making real progress towards a more resilient SH2. Crews are currently focusing on earthworks to build up either side of the highway to existing road level, in preparation for the switch.

Find out more in our latest media release.

Work underway at the Hakanui Straight project.

SH35: Enabling (early) work underway at Rotokautuku (Waiapu) Bridge

Crews have cleared vegetation and started preparation work under Rotokautuku (Waiapu) Bridge near Ruatoria, where part of the Waiapu riverbank was swept away during Cyclone Gabrielle.

To stabilise the area, we’re placing 4-tonne rock bags along the slope, with 200 dolosse (large interlocking concrete blocks) on top to anchor everything into place. This layered defence will help reduce erosion and protect the bridge foundations. The 2 groynes (structures that stick out from the riverbank to help stop erosion) will be repaired too.

A temporary coffer dam (watertight barrier) will be built in the river later this month to temporarily hold back the water from the work area. Fish will be safely relocated before major works begin.

A reminder that there will be no river access under the bridge until work finishes in April 2026 (weather permitting).

Want to know more? Check out our project information sheet.

Crews are removing vegetation, creating access roads and setting up site at Rotokautuku (Waiapu) Bridge, ready for the next phase of repair and strengthening work.

SH35 Kemps Hill willow wall: before and after works progress

Our ‘living wall’ of willow trees is helping stabilise the slope at Kemps Hill, after 3 underslips reduced the road to one lane.

In the before photo taken earlier this year, you’ll see the willows laid out horizontally. This planting method encourages deep root growth into the hillside to help hold it together.

In the after photo, the trees are now growing upright, their intertwining roots strengthening the hillside against erosion. Blackbee Contractors also reinforced the road here with engineered fill.

TREC is planting willow walls at other locations in the region, including on our SH2 Matawai Road site. They’re a key part of our recovery work.

Before and after photo of willow trees at Kemps Hill.

SH35: All go at Rototahe flood resilience site

Warm, dry weather has been on our side over recent weeks, and crews at SH35 Rototahe are making the most of it. Since work began last month, great progress has been made on site.

The team has excavated the subgrade (the foundation layer beneath the road) down 2 metres ready to install 4 of the 6 new culverts (large pipes). In total, the site will feature 8 culverts, including 2 existing ones.

Each culvert (pictured) measures 1.2 metres across. Once connected across the eastern lane, they will be nearly 12 metres in length. Once installed, they’ll play an important part in reducing flood impacts in this low-lying section of SH35.

For more information visit the project website.

Culverts being installed at Rototahe to help reduce flooding.

SH35 Mangahauini Gorge: river temporarily diverted

A 500-metre stretch of the Mangahauini River has been temporarily diverted. This is one of the largest river shifts ever undertaken in Tairāwhiti and will allow crews to construct the new roughened channel to help steady the riverbed and protect the highway from erosion.

On Friday 7 November, the river was carefully redirected so crews could continue placing concrete hanbars and complete piling to anchor the new structures. The river will return to its natural course, flowing over the new channel, in early 2026.

Ahead of the diversion, ecologists and hapū kaitiaki led a methodical defishing process, relocating more than 500 fish and eels. Their work followed ecological best practice and cultural protocols to protect taonga species and minimise disruption to aquatic life.

TREC environmental lead Dathan Proudlove says the scale of the diversion reflects the complexity of the site and the care taken to do it right.

“River diversions are typically under 100 metres,” he says. “This 500-metre shift demanded detailed hydrological modelling, cultural partnership, and ecological precision. It’s not just about redirecting flow, it’s about working alongside nature, not against it.”

Find out more.

The temporary river diversion (visible to the right of the sheet pile wall) allows crews to safely continue work in and around the Mangahauini River.

SH35 Hikuwai Bridge update

Crews are excavating the abutments (bridge ends) for Pier A (northernmost abutment) and building crane and piling platforms at the Hikuwai Bridge site.

Specialised machinery and metal pile casings are being transported up SH35. If you're driving through, please watch for the delivery trucks crossing and give them space to help keep everyone safe.

12-metre long sheet piles are being used to construct a temporary retaining wall at the southern end of the Hikuwai Bridge. They’re being driven up to 2 metres deep below ground.

Road cone-zone: enter with caution and kindness

Crews are reporting instances of drivers speeding and running red lights at some of our work sites. It’s dangerous and disappointing.

Please remember: The people working on our sites are mainly locals - your neighbours, your mates, your whānau. They’re all working hard on the region’s roads, and we want them to get home safely at night.

We’re working with police and local community champions to help improve driver behaviour and continually reviewing our traffic management setups.

You might wonder why road cones and other traffic controls in place even if work appears complete. These setups are often protecting you and our crews while materials settle, inspections are carried out, or follow-up work is scheduled.

Please help keep everyone safe:

• Slow down and obey temporary speed limits
• A red light means stop
• Be patient and follow signage through work zones

Let’s look after each other on the roads this summer.

Summer Roadworks – plan ahead, allow for delays

Summer is roadworks season. The warm weather and longer daylight hours make it the best time to get the most work done.

NZTA is sending regular newsletters to keep you informed about all roadworks on state highways in Tairāwhiti.

Sign up to receive them.

State highway snapshot

Below is a snapshot of construction works either underway or coming soon. You can also view completed, current and future work sites on our interactive map.

Here are some of the construction terms we use:

• Bund – embankment that creates a barrier
• Buttress – supporting structure
• Counterfort drain – drain that improves slope stability by controlling groundwater
• Gabion wall - baskets filled with rocks
• Hanbar – specially designed interlocking concrete blocks
• MSE (Mechanically Stabilised Earth) – a retaining wall construction technique used to stabilise slopes
• Reno mattress – shallow basket filled with rocks
• Rip rap – large rocks
• Rock revetment – protection
• Scour - erosion
• Shotcrete – sprayed liquid concrete
• Soil anchors/soil nails – a device used to hold, restrain and support structures
• Swale - a shallow, planted channel that slows and filters stormwater
• Willow wall – using willows as ‘living walls’ to stabilise slips

SH2 underway

• Otoko Hill (Site K) - overslip repairs.
• Hakanui Straight (formerly called Nesbitt’s Dip) project – flood improvements.

SH35 underway

• Hikuwai Bridge No.1 replacement – enabling (early) works.
• Mangahauini Gabion Wall – Stage 2 – soil nails, buttress and rip rap at the bottom of the existing gabion wall.
• Mangahauini Gorge – river works, drainage and culvert upgrades, highway repair and rebuild.
• Kopuaroa Slip 1 – reinstate SH35 to 2 lanes by installing a soil anchor and shotcrete wall.
• Tōrere – underslip and overslip repairs.
• Paronga (D9) Gully Site – buttress wall with MSE. Two faults to be repaired to reinstate state highway to 2 lanes.
• Kemps Hill subsidence – buttress repair using a willow wall. Three faults to be repaired to reinstate state highway to 2 lanes.
• Rotokautuku (Waiapu) Bridge repairs – strengthening works.
• Rototahe – flood resilience.
• Rotokautuku (Waiapu) Bridge revetment – scour protection.

SH35 coming soon

• Maraehara – underslip repairs.
• Uawa River Scour – Two underslips to be repaired to reinstate state highway to 2 lanes.
• Kopuaroa – drainage improvements.
• Paronga (D9) – drainage improvements.

Whakapā mai – Get in touch

• Email us
• Website
• LinkedIn
• Facebook
• Call us: 0800 80 TREC (0800 80 8732)

If you spot an issue at a work site after hours, call 0800 4 HIGHWAYS (0800 444449).

Sign-up to receive these regular newsletters:

• TREC Pānui (general newsletter)
• TREC Hawke's Bay regional update
• This TREC Tairāwhiti regional update

Local road network

Gisborne District Council is responsible for local roading recovery projects. More information.

Up-to-date information on local road closures.