TREC Tairāwhiti recovery update

Issue 13

23 January 2025

Tēnā koe

Happy new year! We hope you had a relaxing break.

In this update we overview the busy season of work in the area and share other ways you can stay up to date with progress. 

Thank you for your patience and support while this important recovery and maintenance mahi along the highways is underway.

Busy season ahead

It’s all go again with many sites live on both State Highway 35 (SH35) and State Highway 2 (SH2), and a lot more work starting soon.

With NZ Transport Agency Waka Kotahi (NZTA) summer roadworks crews also out and about, the roads will be busy. There will be stop/go at most sites so please allow for extra travel time and visit the NZTA Journey Planner for live traffic updates and to plan your travel.

Most of the NZTA annual renewals work will be complete by May.

A lot of TREC’s recovery work will be complete by mid-year and our focus then moves to larger projects such as:

• Hikuwai Bridge No.1 replacement
• Flood protection work at Nesbitt’s Dip and Rototahe
• More recovery work through the Mangahauini Gorge
• Underslip repairs near Torere Kura (school) in the Eastern Bay of Plenty

Image below shows early testing for shotcreting at Kopuaroa Slip 1 on SH35.

Plan your journey - SH2 to get busier from February

The amount of work through the Otoko Hill section of SH2 has been significant with underslip repairs and extensive drainage installation helping to strengthen and improve Gisborne’s main route north.

The team staggered the already completed projects, however as we push to finish off the remaining sites there will be a few active at the same time through February as well as the NZTA-led Waioweka Gorge closures (more info below). We’re encouraging people to please be patient and plan their journeys.

TREC is making use of the lower traffic numbers during the Waioweka Gorge closures and will undertake early works for Site B (see map below) on Otoko Hill in the same week. We'll share details on this work in our next issue.

Currently underway on SH2:

• Morere, south of Gisborne (more on that below)
• Otoko Hill Site G – work here on an underslip has been underway since last year

Upcoming:

• From Tuesday 28 January Otoko Hill Site J - a new site starting with retaining wall repairs and drainage improvements
• Otoko Hill Site B – tree removal, counterfort drainage and culvert improvements
• Rakauroa (located between Otoko and Matawai) - repair underslip using soil anchors and shotcrete

Waioweka Gorge closures coming up: 11-14 February

NZTA is planning a series of daytime closures on SH2 through the Waioweka Gorge from Tuesday 11 February.

The road will be closed from Kerei Street, Matawai, and Warrington Road, Ōpōtiki, between 10am and 6pm for four days from Tuesday 11 February to Friday 14 February.

This is so contractors can safely replace the road surface at two corners in the Waioweka Gorge with asphalt. There are no viable detours so NZTA encourages road users to plan their journeys outside of the closure times.

You can read more details in the NZTA media release.

New sites underway on SH35

It’s all go on SH35 with Karakia for three new sites having taken place at Awatere Gully (pictured), Kopuaroa (pictured) and Mangahauini Gorge recently.

Awatere Gully: Repair work will see a buttress (support structure) constructed with gabions (baskets filled with rocks) to rebuild and improve stability.

Kopuaroa: Two sites started here last year (Kopuaroa Stream Bridge and Kopuaroa Slip 1) are now back in action after the Christmas break along with the third and newest site at Kopuaroa Slip 2:

• Work under Kopuaroa Stream Bridge is progressing well with debris clearance and erosion protection almost complete.
• The two Kopuaroa slip sites have a similar solution. Soil nails are drilled in then covered with  shotcrete (sprayed on concrete) to stabilise the underslips and protect the toe of the hill from river erosion.

This will ensure a more reliable roading network through Kopuaroa for our communities.

Top image: Project kaitieki and TREC staff at Awatere Gully karakia, Bottom image: Te Whanau a Rakairoa hāpu and TREC staff at Kopuaroa Slip 2 karakia

SH35 Mangahauini Gorge update

Our geologists have been drilling boreholes in Mangahauini Gorge to collect crucial information about the soil, rock and groundwater so TREC knows what needs to be built and where.

Over coming weeks you’ll notice more activity in the area. We’re starting to remove landslide debris in the northern part of the sheet pile wall with work planned to protect the damaged sheet pile wall and make it more stable.

Local crews from H Blackbees and Kuru Contracting will be working together on this which we’re expecting will take around eight weeks, with very little traffic impact.

This is important work so the river can flow closer to its pre-cyclone alignment which is further away from the highway. Along with helping to reduce flooding over winter, it will also prepare the site for our future Mangahauini Gorge work.

The TREC team continues to work with Iwi, hapū and other community members on additional designs to make this area safer and more resilient. We’ll keep sharing more information as this work progresses.

The image below shows a crew operating a machine borehole with a drilling rig. In the background you can see the old failed sheet pile wall and landslide debris.

Follow our progress on a new online map

TREC and local contractors continue to make great progress towards completing recovery work on state highways in Tairāwhiti. Construction is now complete on almost 80% of the projects in the region (faults we have fixed).

Keen to see what’s happening and where? Check out our new interactive map which shows where TREC is working, what work is complete, and what’s coming up next.

The map is updated fortnightly to keep up with progress.
 

State highway snapshot

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

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 (large rocks)

SH2 underway

• Otoko Hill Slip #2 - Hill stabilisation using soil anchors, shotcrete, and rip rap (large rocks)
• 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
• Allen’s Existing Wall – Reinstate underslip under existing wall using soil anchors and shotcrete

SH35 recently completed

• Oweka – Fix underslip with a reinforced buttress (supporting structure)
• Ihungia Road – Fix underslip with buttressing (supporting structure) and rip rap (large rocks)
• Mangahauini Gabion Wall – Stage 1 – Buttress (supporting structure) and rip rap (large rocks) 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 (supporting structure) and rock revetment (protection) 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 #3 – Reinstating state highway to two lanes, buttress support and rip rap (large rocks) to prevent future river erosion
• Kopuaroa 1 Stream Bridge – Scour protection beneath bridge using soil nails and shotcrete (sprayed concrete)
• 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 (baskets fill with rocks) to repair the underslip
• Kopuaroa 1 Slip – Reinstate SH35 to two lanes by installing a soil anchor and shotcrete (sprayed concrete) wall
• Kopuaroa 2 Slip – Build a 250m long buttress (supporting structure) to support SH35 and provide additional drainage

SH35 coming in early 2025

• Kemps Culvert – Following Stage 1 repair, reinstate the inlet/outlet of the culvert and construct further drainage improvements
• Waiapu Bridge revetment – Repair the scour at the south end of the bridge and construct a major revetment with dolosse (interlocking concrete blocks) for futureproofing
• Mangahauini Gabion Wall – Stage 2 – Install 160x9m long anchors, rip rap and a mechanically stabilised earth (MSE)/retaining wall to permanently support SH35

Road notifications

Nightworks on SH35

NZTA’s annual summer renewals work is going well. You can sign-up for detailed weekly updates by emailing Stakeholder Manager Lynne.Chaffey@Downer.co.nz

Two lots of reseals will be done under nightworks with delays of up to 15 minutes possible:

• SH35 between Tatapouri Boat Ramp and Okitu Scenic Reserve from 28 January to 1 February.  The work will take place between 6pm and 6am. Stop/go traffic management and a temporary 30km/h speed restriction will be in place. Delays of up to 15 minutes are possible.
• SH35 Awapuni Road between Lytton Road and the Speedway (Makorori) from 27 January until 3 February.  The work will take place between 6pm and 6am. Stop/go traffic management and a temporary 30km/h speed restriction will be in place. Delays of up to 15 minutes are possible.

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.