TREC Tairāwhiti recovery update

Issue 14

7 February 2025

Tēnā koe

TREC continues to deliver on its recovery programme with most of the work expected to be complete by mid-2025, and some larger projects continuing through to 2026.

In this issue we share State Highway 2 (SH2) Otoko Hill progress photos, information about upcoming road closures and planned work, and details on where you can come and chat with our team on the Coast.

Don’t forget to check out our new online map, which shows our completed, future and current work. Updated fortnightly, it's a great way to keep track of TREC progress.

Upcoming SH2 closures

A reminder that next week, from Tuesday 11 to Friday 14 February, SH2 through Waioweka Gorge will be closed each day for important maintenance work.

This work, being led by NZ Transport Agency Waka Kotahi (NZTA) Bay of Plenty, will see this section of highway closed between 10am to 6pm each day.

During these closures TREC, and NZTA Gisborne crews will also be working on SH2, between Otoko Hill and Matawai.

We’re taking advantage of the reduced traffic to get things like resealing, tree removal, and drainage improvements done as quickly as possible. There is no viable detour so please plan your journey. Read more.

Two more Otoko Hill sites complete

We’ve finished six of the nine Otoko Hill sites, transforming this once vulnerable section of highway into a more reliable and safer route.

Crews recently completed work at two sites on Otoko Hill:

• Pictured below is Site L, where counterfort drains have been installed to reduce water in the hillside and redirect it away from the road to protect it.
• A second site on Otoko Hill, Site I (pictured below), located across the highway from Site L, also involved installing counterfort drains.

The crew also repaired an underslip by constructing a buttress (supporting structure).

We’re aiming to finish all work in this area in late 2025.

Top 'before' and 'after' photos: Site L, Bottom 'before' and 'after' photos: Site I

Action stations at Kopuaroa

Last issue we shared an image of shotcrete (sprayed on liquid concrete) testing on Kopuaroa Slip 1.

The images below show the other two Kopuaroa sites nearby:

• Kopuaroa Stream Bridge - you can see scour (erosion) protection work beneath the bridge. In the background, the crew is re-installing erosion sediment control to look after the awa during the works.
• Kopuaroa Slip 2 - you can see an underslip that has been excavated out and is in the process of being replaced with a mechanically stabilised earth (MSE) wall.

Left: Kopuaroa Stream Bridge, Right: Kopuaroa Slip 2

The green, green grass of home

As TREC continues to tick off the recovery projects, road users might notice green hillsides replacing construction sites across Tairāwhiti’s state highways.

‘Hydroseeding’ is often one of the final jobs on a site and helps in several ways - preventing erosion, improving soil health, and reducing dust. Plus, it makes the area look better!

The process involves using a large hose to spray a mixture of water, seeds, mulch and fertiliser onto the surface to promote growth.  TREC monitors the growth until it reaches 80% when it is nicely settled in and doing its job.

Left: SH35 Whakaari Bluff, Right: SH35 Ihungia

TREC kōrero on the Coast

TREC is again looking forward to joining Gisborne District Council roadshows on Tuesday 11 February:

• 9.30-11.30am, Te Puna Manaaki in Wharekahika
• 1-3pm, Te Puka Tavern in Tokomaru Akau

Come and say kia ora!

State highway snapshot

Below is a snapshot of construction works either recently completed, underway or coming soon.

Here are some of the construction terms we use below:

• Buttress – supporting structure
• Counterfort drain – drain that improves slope stability by controlling groundwater
• Dolosse – interlocking concrete blocks
• Gabion wall – baskets filled with rocks
• Rip rap – large rocks
• Rock revetment – protection
• Scour – erosion
• Shotcrete – sprayed liquid concrete

SH2 recently completed 

• Otoko Slip Soldier Pile Walls 
• Otoko Hill Slip #3 - Hill stabilisation and drainage improvements
• Otoko Overslip #2 - Hill stabilisation using counterfort drains
• Waikohu Bridge #3 - Repair scour around bridge pier with rip rap

SH2 underway

• Otoko Hill Slip #2 (Site G) - Hill stabilisation using soil anchors, shotcrete, and rip rap
• Allen’s Existing Wall (Site J) – Reinstate underslip under existing wall using soil anchors and shotcrete
• Morere – Counterfort drain installation

SH2 coming in early 2025

• Rakauroa – Reinstate underslip using soil anchors and shotcrete
• Otoko Hill – Tree removal and major drainage to stabilise slopes

SH35 recently completed

• Oweka – Fix underslip with a reinforced buttress
• Ihungia Road – Fix underslip with buttressing and rip rap
• Mangahauini Gabion Wall – Stage 1 – Buttress and rip rap at the bottom of the existing gabion wall to stabilise SH35 until Stage 2 works start
• Hikuwai Bridge No. 1 early investigations – Drilling for soil samples and using electro-seismic scanning to find underground obstructions to help with the bridge design
• Mangakuri Stream Bridge – Riverbed and slopes lining with rock
• Whakaari Bluff rock revetment – Road buttressing and rock revetment on a major scour by the Hikuwai River
• Te Anaputarua (Aka Whanarua) – Soldier Pile Wall with drainage improvements
• Kahuitara Culvert (Jeru Straight) – Replace culvert segments and clear out riverbed from built-up aggregate

SH35 underway

• Rotokautuku (Waiapu) Bridge repairs – Reinstate bridge bearings and strengthening works
• Makatote dropout #2 – Buttress support and rip rap to prevent future river erosion
• Makatote dropout #3 – Reinstating state highway to two lanes, buttress support and rip rap to prevent future river erosion.
• Kopuaroa 1 Stream Bridge – Scour protection beneath bridge using soil nails and shotcrete
• Mangahauini Gorge early investigations - Drilling for soil samples to help with the design of this major project
• Mangahauini Gorge early works - River training and sheet pile wall strengthening
• Awatere Gully – Buttress wall with gabions to repair the underslip
• Mangahauini Gabion Wall – Stage 2 – Soil nails, buttress and rip rap at the bottom of the existing gabion wall
• Kopuaroa 1 Slip – Reinstate SH35 to two lanes by installing a soil anchor and shotcrete wall
• Kopuaroa 2 – Build a 250m long buttress to support SH35 and provide additional drainage
• Opape underslip – Buttress with gabion wall

SH35 coming in early 2025

• Kemps Culvert – Following Stage 1 repair, reinstate the inlet/outlet of the culvert and construct further drainage improvements
• Waiapu revetment – Repair the scour at the south end of the bridge and construct a major revetment with dolosse for futureproofing
• Hikuwai Bridge No.1 Replacement – Enabling works

Road notifications and delays - SH2

Tuesday 11 – Friday 14 February Waioweka Gorge Closure from 10am - 6pm (details above)

Tuesday 11 February – mid-April - TREC will be upgrading drains, trimming and removing trees on a two kilometre stretch of SH2, Otoko Hill, between Hihiroroa Road and Fitzgerald Road.

• Hours of work are 8am to 5pm.
• Stop/go will be in place to safely do this work.
• Delays of up to 15 minutes are expected however this wait time could be longer if a tree is being felled.
• We encourage you to plan your journey using the NZTA Journey Planner and travel outside of these work hours if possible. During the first week of work, a pilot vehicle will escort road users through this site safely.

Wednesday 12 – Saturday 15 February - NZTA will be resealing the road between Te Wera Road and Matawai Village from 6am to 6pm. Stop/go will be in place, please allow for delays of up to 10 minutes.

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 (fortnightly)
• This TREC Tairāwhiti regional update (fortnightly)

Local road network

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

Up-to-date information on local road closures.