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TREC Tairāwhiti Recovery Update

Issue 4

22 August 2024

Tēnā koe

Welcome to our Tairāwhiti TREC e-newsletter, where you can find the latest information on state highway recovery progress across the rohe. We aim to share these short updates with you fortnightly.

This edition includes information on working with our Iwi partners, a temporary stream diversion on State Highway 35 (SH35) and where you can sign-up to our weekly road notifications. The weekly notifications include locations of our stop/go sites and travel time delays.

State Highway snapshot

Below is a snapshot of construction works either recently completed and/or underway.

State Highway 2 (SH2) recently completed

Two of nine sites on Otoko Hill (Otoko Hill Slip #1, Otoko Hill Instability)
Waikohu Bridge #2 scour protection

SH2 underway

Wairakaia Bridge #2 scour protection
North Morere slow vehicle lane re-instatement

SH2 underway coming soon

Further two sites on Otoko Hill (Otoko Hill Solider pile walls, Otoko Hill Slip #2)
Waikohu Bridge #3

SH35 recently completed

Mangahauini dropout
Mangatuna River Slip
Kopuaroa Subsidence site (further work to come in 2025)

SH35 underway

Mangakuri Stream Bridge
Mangatuna Culvert 1
Mangatuna Culvert 2
Awatere slip #2
Kemps Hill Culvert urgent works (main work to start in 2025)

SH35 coming soon (Aug-Sept)

Maka Valley dropout #3
Waipare Bluff rock revetment
Rotokautuku Bridge Improvements
Jeru Straight Culvert
Ihungia Road
Kopuaroa 1 Stream Bridge


	Highway highlights SH2 north Morere Work to install counterfort drains followed by the reinstatement of a slow vehicle lane on SH2 south at Morere is going well and looking to finish ahead of schedule. Local contractors Siteworx are undertaking this work. See our ‘did you know? section' below for more detail on this type of work. Further work is planned at Morere at a slip site early next year when the weather is drier.



	Temporary stream diversion SH35 Mangakuri Stream Bridge Repair work has started at Mangakuri Stream Bridge just north of Whangara. Rock work to strengthen and protect a heavily scoured base beneath the bridge as well as recontouring the southern bridge approach will be underway for the next couple of months. A temporary stream diversion and de-fishing took place before the work could get underway to ensure a sufficient and safe working space for Parata Contractors, who are undertaking the work. De-fishing is a practice where we catch and relocate fish to a safe area upstream or downstream before work begins. The temporary river diversion can be seen covered in white cloth to keep the water clean before relocating fish and eels. Work is taking place Mon to Fri from 6am – 6pm with temporary speed restrictions in place. Photo below: De-fishing to catch and relocate fish to a safe area upstream or downstream.



	SH35 site visits with Ngati Porou kaitiaki and representatives Working with our Iwi partners TREC is working alongside Kaitiaki from Ngati Porou and Te Aitanga-a-Mahaki (Mahaki), offering staff an opportunity to partner and learn more of the local stories from iwi representatives who will be involved in projects that fall within their respective rohe. Mahaki and Ngati Porou are two of eight iwi groups in Tāirawhiti with a connection to the recovery corridor, that TREC is working with. As Tiriti partners, Mana Whenua play an important role to ensure projects take into account a Te Ao Māori perspective. Kaitiaki will be involved in cultural monitoring, Cultural Impact Assesments and identifying potential issues pertaining to the environment. Photo below: SH2 Otoko site visits with Mahaki kaitiaki and representatives.


	Summer works programme Work is currently being planned for the summer construction season from September 2024 through until approximately April 2025 and design is well underway for the 24/25 maintenance and operations renewals programme. We’re looking at resealing approximately 125 lane kms and rehabilitating approximately 11 lane kms on the Tairāwhiti network. The lengths are subject to finalisation of design approvals. Lane kilometres refer to the total length of a highway, accounting for each single lane. For example, if a road has two lanes and is one kilometre long, it would be considered two lane kilometres. Our summer construction programme has up to 12 projects planned on SH35 and a further seven on SH2. More information and details on this summer package of works will be shared in this e-newsletter next month.

Road notifications

A full road closure on SH35 at Rotokautuku Bridge will be in place for 30 minutes on Monday 23rd September from 12pm – 12.30pm.

During this time crews plan to jack up the bridge by a few millimetres to carry out work, including fixing the bearings and welding new cross bracing.

This 30-minute closure will occur twice in October and again in November. We will share details in this e-newsletter as dates are confirmed.

Please sign-up to our weekly planned report, emailed direct to you every Friday with where these weekly stop/go sites are located. Sign-up here: lynne.chaffey@trec.nz


	Did you know? The Tairāwhiti region has long been susceptible to erosion due to our fragile soils and geology. The amount of rainfall the region has experienced in recent years has exacerbated the issue. A significant amount of recovery work TREC is undertaking includes strengthening and supporting the surrounding areas where our state highways run, using methods such as buttressing and the installation of counterfort drains. A lot of this work is being undertaken on Otoko Hill. Counterfort drains are trenches filled with drainage materials like gravel and pipes. They help stabilise slopes by reducing water pressure in the soil. Think of them as underground channels that guide water away to prevent slips. Buttressing refer to providing support to the road to strengthen it from collapsing. This can be done by adding engineered fill (compacted material), drainage and geo-grid as appropriate to form part of the road structure. Photo 1 below shows buttressing which adds support to the road. Photo 2 below shows a counterfort drain.