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TREC Tairāwhiti recovery update

Issue 27

8 August 2025

Tēnā koe

In this edition we take a look at the progress of 2 recovery sites north of Tikitiki on State Highway 35 (SH35) and provide updates on 3 of our big projects. TREC has also been recognised with an award win you can read more about below.

Thanks for your ongoing patience as we continue our recovery mahi.  


	Layer upon layer at Paronga (D9) North of Tikitiki crews are busy at 2 of our larger sites on SH35; Paronga (D9) and Kemps Hill. At Paronga there are 2 underslips requiring repairs. The first is on the southern slope and involves building a buttress wall and in coming weeks the second underslip will see an MSE (Mechanically Stabilised Earth) wall constructed. The buttress wall is being built up in many layers of structural fill (compacted soil and gravel). Each layer is 900mm thick and added 1 at a time, compacted and tested before adding the next. The team is currently on layer 24 of 25 (including the road surface). Twelve reno mattresses (named after the town of Reno, Nevada in the United States where they were first used extensively) have also been installed in the southern slope for erosion control. You may have seen stories about gabion baskets in our previous newsletters. These mattresses are similar. They’re mesh wire baskets filled with rocks, but have a low-profile, are shallower in height, and as their name suggests, are shaped like a mattress. Reno mattresses, similar to gabion baskets, are being used for erosion control at Paronga.


	Two down and 1 to go at Kemps Hill Crews are using willow walls to stabilise the hillside as part of a buttress repair job at Kemps Hill on SH35. Also known as a live willow wall, it involves using live willow cuttings woven or bundled together then placed in the soil to root and grow. The willows we're using are sterile so they won’t spread or become invasive. There are 3 sections (or faults) of highway here that needed to be repaired with the central and southern faults now completed. The team is waiting for a fine weather window before sealing the road and finishing up work. We expect to return in October to complete this final section. The live willow wall at Kemps Hill.


	SH35: Update on Tōrere slip repairs Heavy rain has recently hit the Bay of Plenty, causing flooding and slips across the region. Te Kura o Tōrere recorded around 73mm of rainfall in a short window, leading to further movement in the area we were repairing. In response, our team is carrying out emergency works to excavate and stabilise the new slip before continuing with the wider project. Te Kura o Tōrere has kindly agreed to allow excavator access through the kura (school) grounds to reach this area. The emergency work is expected to be complete this week. It's being staged; starting at the top of the slope and progressing downward. Extra traffic controls are in place near the kura to help keep everyone safe, especially during school hours. Thank you for your patience and support as we continue this important mahi. Crews working on the overslip.


	We like to move it move it Our Hakanui Straight (previously Nesbitt’s Dip) project team has successfully moved into our new site office, ready to tackle the upcoming task of raising the road. Ground preparations are underway for the services relocations, including fibre cables and power poles. The poles will move further south of the road to make way for the new 3-metre-high embankment. In early spring, we’ll upgrade the culvert at Hakanui Stream with a larger and wider (1.8m diameter), fish-friendly passage to boost water flow and prevent floodwater from backing up on to SH2. The fish passage supports the local ecosystem, benefitting eels, fish and other aquatic life. Currently, winter work focuses on installing stock and silt fences, and preparing the site for major construction. It starts with digging drainage channels (swales) on both sides of the road corridor to manage sediment and water runoff, protecting the Hakanui Stream. Traffic management will include road shoulder closures and a reduced speed limit to 50km/h during the works. Stay updated on the progress by visiting the Hakanui Straight project page. Power poles are being moved south, further away from SH2 to make way for the new 3-metre-high embankment.


	I spy at Hikuwai Who’s spied the bright yellow machine at Hikuwai this week? It’s a track mounted drill rig capable of drilling to 100m in depth. We are assessing the condition of material under the pier locations before main works start. Our bridge casings are on their way to Napier Port where they will be off-loaded and trucked to Gisborne later this month. The casings are the protective coverings that will act as a sleeve to shield the bridge columns. They improve the column’s durability and load-bearing capacity. This week crews are also finishing up work on the temporary road and planning what will be a low-impact traffic switch to move traffic onto the realigned road. Visit the project website for more information. The bright yellow drill rig at Hikuwai this week.


	Community at the heart of recovery The collaborative work between TREC, Iwi, hapū and local contractors has been recently recognised with a Social Value Through Procurement award. The Chartered Institute of Procurement and Supply (CIPS) award celebrates projects that deliver positive social outcomes while also delivering goods, services, or infrastructure. This award highlights the success of a collaborative approach with Iwi and the local contractor network to deliver better outcomes for communities, recognising local solutions to local issues. Thank you to our Iwi partners and local contractors for your ongoing mahi. Ehara taku toa he toa takitahi Ko taku toa he toa takitini The award is not the work of a single entity But the collective result of the multitudes. We are proud of the effort of all involved and this award is reflective of those collective partnerships. Some of the hard-working local contractors delivering TREC mahi.

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
Dolosse - interlocking concrete blocks
Gabion wall - baskets filled with rocks
MSE (Mechanically Stabilised Earth) – a retaining wall construction technique used to stabilise slopes
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
Willow wall – using willows as ‘living walls’ to stabilise slips

SH2 underway

Matawai Road – willow wall to stabilise slip.
Otoko Hill (site K) - overslip repairs.
Otoko Hill (site M) - underslip 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.
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.
Makatote dropout #2 – buttress support and rip rap to prevent future river erosion.

SH35 coming soon

Rotokautuku (Waiapu) Bridge revetment – scour protection.
Rotokautuku (Waiapu) Bridge – southern end strengthening.
Maraehara – underslip repairs.
Uawa River Scour – 2 underslips to be repaired to reinstate state highway to 2 lanes.
Kopuaroa – drainage improvements.
Paronga (D9) – drainage improvements.