Multiple significant weather-related slips closed SH1 Mangamuka Gorge in August 2022. NZTA is working at pace to keep people moving on the Far North roading network now and in the future. We’re aiming to create reliable and safe roads which will better withstand weather events.
The official detour route is via SH10 and may add up to 40 minutes to your journey. This route is safe for all vehicles, including heavy and freight vehicles.
The Twin Coast Discovery Route is also open and provides a scenic alternative. This route is only suitable for light vehicles and campervans.
Plan your journey by using the NZTA Journey Planner:
Journey Planner – Northland(external link)
A programme of works to repair the 15 critical slips along SH1 Mangamuka Gorge is underway, following $100M of funding announced at the end of 2022 and a construction contract awarded in late-February 2023.
Weather events throughout 2023 caused additional slips within the site area, adding complications to existing slip sites and subsequently creating an increase in scope that resulted in delays to the initial work programme. The number of slips more than doubled to 35, with 15 defined as critical.
The earlier repairs completed during the previous closure in 2021 held up well and were undamaged in the more recent weather events, requiring no additional work to be undertaken in these areas.
The road is expected to reopen by Christmas 2024.
The project will repair State Highway 1 (SH1) through Mangamuka Gorge, providing a safe and reliable State Highway network to reconnect communities and restore access to essential services in the Far North district of Te Tai Tokerau Northland, and enhance connectivity with broader New Zealand.
A reliable and resilient roading network is essential to ensure that whānau, friends, businesses and communities stay connected. This is especially important for communities in the Far North where in many places, people live rurally and rely on state highways to get where they’re going safely.
SH1 through Mangamuka Gorge closed in August 2022 for the second time in two years due to significant slip damage caused by severe weather.
Repair work is underway on the 15 critical slips. As part of the repair, we’ll be making the ground less susceptible to slips by improving the drainage through the gorge, so it’s more suitably equipped to handle the increase in severity and frequency of weather events.
CloseEmergency Response – completed
Recovery – underway
To find out more about the Mangamuka Gorge and the work we’re carrying out, more information is available below.
CloseCheck out the progress made on the repairs to State Highway 1 through Mangamuka Gorge. This flyover of the entire site, carried out at the beginning of July 2024, shows how much has changed onsite compared to the previous flyover from December 2023. We're on track to reopen the road by Christmas 2024. We're currently working on all the critical slips – we've finished piling on nine of the slips, three of which are complete, and we've just drilled the final 1050 millimetre diameter piles for slips A1/A2. We'll get underway with physical works on the newest slip, A47, in early August 2024.
