TREC Hawke's Bay recovery update

7 February 2025

Tēnā koe,

In this update, we share the start of a new project north of Tūtira on State Highway 2 (SH2) and highlight some recently completed projects. January has also been a busy month for work on Devil’s Corner on SH2 - check out our timelapse video below.

Repairing three slips at Sandy Creek

Last year we installed a sheet pile retaining wall at Sandy Creek, just north of Tūtira on SH2, to address damage caused by Cyclone Gabrielle. Our second significant project at Sandy Creek, which started in January, is made up of three small slips.

To repair the slips large soil nails will be drilled into the slip face, then erosion matting and rip rap (large rocks) added to stabilise the bank and prevent further erosion. We will also improve the drainage and reinstate the guardrail.

Like the Sandy Creek name suggests, there is a stream just below where we’re working. TREC has strong environmental controls to ensure slip material won’t enter the stream and the aquatic life is safeguarded.

Prior to works starting the ecology team undertook a pre-start bird survey to ensure we don’t disturb any native birds that may be in the works area. There were no active nests found.

We expect this project to be complete by May 2025.

Crew working at Sandy Creek.

Mohaka underslip completed

The Mohaka underslip on SH2 is one of several recovery sites south of Wairoa. Repairs are focused on reducing the possibility of further slips by making sure the stormwater runoff from the road is controlled and water on the ground can drain away. This helps to minimise erosion.

Counterfort drains have been installed up to 5m deep on the southern slope. These are deep trenches filled with gravel and rock that allow water to ‘escape’ from the surrounding soil. The drains improve slope stability by controlling groundwater pressure, giving it more resilience during weather events.

The road embankment was then reconstructed using a geotextile reinforced fill before returning the road to its original alignment. The final piece of work was recontouring and landscaping the slope. It has been hydroseeded and planting will take place in March or April when the weather is better suited for this activity.

The final recovery site to be completed in this area is on the hillside around the broken guardrail on the Mohaka Rail Viaduct. This is scheduled to start in April 2025.

Before and after photos of Mohaka underslip.

Devil’s Corner activity ramping up

Work on Devil’s Corner (Site I) on SH2 is progressing well. Watch our timelapse video (link below) to see the significant progress made excavating and stabilising the hillside down to solid ground so piling work can begin in March. The excavation is currently 11m below the road with only 1m to go.

All projects in the upper section of Devil’s Elbow (see map below) are currently active:

• Project R: is currently focused on drainage
• Projects J and H: concrete ground beams are being poured to support the guardrails. You may have seen the temporary guardrail being moved at Project J; this will keep road users and crew safe while work continues here.

Watch as the hillside is excavated down to the solid ground that will be the foundation for a new retaining wall to be constructed on. In the last two weeks of January 1000 cubic metres (200 truckloads) of material was excavated.

KiwiRail: Ashhurst rail bridge

We’ve completed the first KiwiRail site at Ashhurst. If you look closely at the ‘before’ image below you can see scouring around the piles on the far right.

The TREC team removed loose material before the existing bank was shaped in preparation for geofabric to be placed over the bank. This was then covered with specific types of rock that will help to prevent further scour.

SH50 Chesterman's Bridge

Finished in time for Christmas, work focused on repairing the scouring (erosion) on the abutment (end of the bridge) which you can see on the right of the top image below.

Debris was removed to encourage the stream to flow through the central span of the bridge, which is its natural course. The ground was contoured ready for geotextile matting and rip rap (large rocks) that you can see below. With the combined approach the abutment on the right (which was vulnerable) is now protected from future erosion.

Site snapshot

SH2 Hawke’s Bay North

• Slip repair work north of Mohaka/Raupunga is complete.
• Repairs at Mohaka Rail Viaduct, the final site in this area, are planned to start in April.
• Slip stabilisation at Sandy Creek has started.
• The road surface where we installed the sheetpiling retaining wall at Sandy Creek will be renewed alongside some NZTA road surface renewals as part of their annual maintenance programme. These will be done together in the next couple of months.

SH5 Napier to Taupō

• The site of three underslip repairs at Māori Gully is being prepared for construction (in March) by clearing debris.
• Tarawera Culvert repairs will begin mid-year.

SH2, SH50, SH51 Hawke’s Bay South

• SH50 Glencoe Gorge underslip repairs are planned to start later this month.
• SH51 Tutaekuri Bridge repairs are planned to start in early May.

SH38

• Tarapatiki underslip repairs are planned to start in March.

KiwiRail repairs

• We completed our first site at Ashhurst before Christmas.
• This year we have started two sites between Woodville and Ormondville, one of these has finished, with the other to be hydroseeded to complete the site. 
• A further five KiwiRail sites will start this month.

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).

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• TREC Pānui (regular newsletter)
• TREC Hawke's Bay regional update (fortnightly)
• TREC Tairāwhiti regional update (fortnightly)

Local road network

Hawke’s Bay councils are responsible for local roading recovery projects.

• Napier City Council
• Hastings District Council
• Wairoa District Council
• Central HB District Council