TREC Hawke's Bay recovery update

17 April 2025

Tēnā koe,

In this edition we feature one of our Devil’s Elbow sites (Project R) on State Highway 2 (SH2) and look forward to the shortened traffic management through the Devil’s Elbow section.

We also explore the anchor and tie-back system being implemented on State Highway 5 (SH5) at Māori Gully, and take a look at simple yet effective solutions for rail within time and space constraints.

Pause on roadworks coming up

The NZ Transport Agency Waka Kotahi (NZTA) often put roadworks on hold during busy holiday periods to help keep traffic moving and avoid delays for travellers.

Aside from the odd site – for example, emergency repairs – most roadworks will stop during the following times for Easter and Anzac holiday periods.

Easter:

• From 12pm Thursday 17 April until 23.59pm Monday 21 April
• Works at Glencoe Gorge on State Highway 50 (SH50) will pause until Monday, 28 April

Anzac Day

• From 12pm Thursday 24 April until 23.59pm Sunday 27 April

The days between Easter and Anzac Day are working days for crews. Traffic management will remain at some sites on non-workdays to keep everyone safe.

SH2: Continued progress at Devil’s Elbow

Work is progressing well at the remaining sites at Devil’s Elbow (see map below). 

At Devil’s Corner - Project I we have started concrete and structural works and the permanent anchoring. The 9m deep permanent piling is expected to start mid-May. 

From today we have shortened traffic management at Devil’s Corner, Project I during the day. 

At Project O we’ll be returning for night work for about 3 weeks, starting Sunday 27 April. A ground beam, guard rail and rumble strips will be installed. More details will be provided nearer the time.

We still have minor works being completed on Project R (more on that below) and Project H before the traffic management is removed from these projects. 

Project J – is 75% complete, with the final stage paused to be tied in with other work. This is scheduled to be completed in May.

SH2: Strengthening work at Devil’s Elbow

At Devil’s Elbow, Project R, damage caused by Cyclone Gabrielle included a large underslip. In our last issue we showed you a photo of work underway, below is a wider view showing the natural gully, and the steepness of the hillside, which water would flow down in a rain event. 

Working on drainage here, above and below the road, required careful planning. Below the road, we used an existing culvert pipe and added a manhole to connect the old and new sections of culvert. Above the road, we extended the culvert to make room for a wingwall, which strengthens the area around the culvert, holds soil back and helps guide water flow.

To enhance stability and prevent erosion, we used geotextiles (a strong fabric designed for soil stability) for reinforcement. Our goal was to channel water from the hillside under the road and over reno mattresses (flat wire mesh containers filled with stones that reduce water flow energy) to prevent erosion. We also created a ponding area to manage heavy rain.

The team faced several challenges during construction. Drilling a 4m deep and 600mm wide hole with a 20-ton digger turned out to be tough because limestone rocks kept moving the drill off course. This site is now almost complete with final minor works being done. The traffic management will be off the road shortly.

Effective drainage will move large volumes of water in rain events from the steep slope and natural gully, underneath the road, and out the other side.

Providing extra support at Māori Gully

The road above Māori Gully, where we’re repairing 3 underslips, has steep drops on both sides. We’re building a retaining wall, and to secure it we’re using a system of anchors and tie-backs (rods or wires) which will help boost stability and resilience against future weather events.

This method, known as "deadman anchors," refers to something immovable, like a dead weight. We are installing 10 anchors in total.

The anchors are located on the opposite side of the road from the retaining wall and are buried 1.2m deep under the road surface. Our crew is drilling a trench from the retaining wall for the tie-backs to connect with the anchors, providing the necessary tension to keep the wall in place.

Over the past 4 weeks, we’ve excavated and installed all 10 deadman anchors and anchor tie-back rods up to the centreline of the road. These will connect to the retaining wall once we shift works to the southbound lane.

We’re now installing the barrier on the northbound lane and will soon pave this lane ready to begin work on the retaining wall in the southbound lane.

Steep drops on both sides of the road create a challenging work area for the crew while they install the anchors.

Precision in motion - navigating tight spaces and timelines with a well-oiled team

Our team, along with local contractor Ngaio, recently tackled a hillside failure repair right above the rail line. We started by clearing out loose debris and removing 2 large pine trees that were causing instability. Next, we reshaped the slope to a 45-degree angle and applied coconut matting to ensure long-term stability. To manage water flow, we constructed a concrete swale (water channel) with rip rap ends to slow the water and prevent scour.

This project required extra care due to its proximity to the track and limited space for machinery. Working around live rail means managing tight work windows, which requires precise coordination and a strict plan. The variety of rail recovery sites and the live track keep things interesting for the crews, and they enjoy the challenge.

Rail site A3015 near Ormondville shows Ngaio Contracting constructing the concrete swale, and the final view with the grass coming through the coconut matting and a clear path to direct the flow of water from the hillside and under the track.

Site Snapshot

SH2 Hawke’s Bay North

• We will be starting the micro-piling next week for the underslip repairs at Mohaka Rail Viaduct
• Slip stabilisation at Sandy Creek continues to make good progress and work on the guardrail beam is approximately 50% complete. This site is expected to be finished by mid-May
• The road surface where we installed the sheetpiling retaining wall at Sandy Creek will be renewed next summerseason, taking advantage of better weather conditions so the surface has the best chance of longevity
• White Pine Bush underslip repairs are expected to begin late July

SH5 Napier to Taupō

• 3 underslips at Māori Gully – work on the northbound lane is nearly complete, and will shortly move to the southbound lane for the biggest of the three slips (see above)
• Tarawera Culvert repairs will begin in the second half of the year
• Captain’s Culvert and Eskdale substation shoulder repairs will begin in Spring

SH2, SH50, SH51 Hawke’s Bay South

• At SH50 Glencoe Gorge underslip repairs are going well with the foundation layer of Ecoreef blocks being filled. We’re now 55% of our way through installing the Ecoreef blocks. We will be complete by the end of June. See more here
• SH51 Tutaekuri (Waitangi) Bridge repairs are planned to start in June

SH38

• Tarapatiki underslip repairs are almost complete

Rail progress

This week we are adding the site numbers, so you can see the locations on our interactive map. This map is updated every two weeks.

Eight sites are underway, including: 

• Repairing 2 rock fall scaling sites in the Manawatū Gorge (A3002 and A3003). 
• We are repairing the washout to embankment and undertaking drainage repairs at Mangatera by Dannevirke (A3007)
• South-west of Makotuku we are repairing the embankment failure below Bridge 151 at the Mangatewainui Stream (A3009)
• We are repairing a washout of an embankment and the shallow landslide above the track. We replaced the culvert during a ‘block of line’ (period of time when a railway line is closed for maintenance or construction) last weekend and installed a stormwater pipe (A3011). This is near Makotuku
• In the cluster of sites between Ormondville and Kopua we are repairing the embankment failure below the rail (A3018)
• We are repairing the slope failure below the viaduct in the Ormondville cluster (A3019)
• We are repairing the washout of the rail embankment, in Poukawa (A3021)

Starting soon:

• In the Manawatū Gorge we will also repair a shallow landslide above the track (A3004) and on 2 sites close together in the Ormondville Cluster (A3016 & A3017)

Hastings south - culvert improvements

• Over the next few months we will be replacing some further culverts underneath the rail lines

Bridge 217 (beside SH51 Tutaekuri Bridge) repairs are expected to begin in late winter.

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 (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