New slips add to challenges in Manawatū Gorge


The NZ Transport Agency says further small slips in the Manawatu Gorge have added to the challenges facing work crews and engineers working hard to stabilise hillsides and rock faces to make the road safe for traffic.

Manawatū Gorge Road

Two new slips came down over the weekend near the Kerry’s wall rock face, damaging the rock fall netting that had been put in place after the Anzac day slip.

Transport Agency Highway Manager Ross I’Anson says while the weekend’s slips were relatively small, the continued instability at these slip sites is frustrating efforts to make the road safe, and the latest slips add to the complexity of the geotechnical work being undertaken by engineers to assess the safety of the gorge.

“Given the unpredictable environment in the gorge and its complex geology, it’s vital that the geotechnical assessments are thorough in order to understand what additional work may be needed to ensure the safety of road users, and to ensure that decisions on when to reopen the road are based on the best information available.”

With the Manawatū Gorge now being closed for just over two months, Mr I’Anson says he is very aware of the frustrations and stress of business owners who are affected by the Gorge closure, and motorists who need to use the alternative routes of Saddle Road and the Pahīatua Track, as well as those residents who are experiencing extra traffic flows.

“We understand how vital this route is for the region and how disruptive this closure is, but the fact is that the recent slips have significantly changed the rock faces above the road, and we need to be confident that any additional risks that the newly exposed rock might pose for road users are addressed before traffic can return. The recent slips have resulted in new cracking in the rock faces on either side of the slips and we need to identify if there is a risk of additional rock falling onto the road, and most importantly what additional work may be required to ensure safety. The geology of the gorge is complex, and these assessments must be very thorough to address that complexity.”

Mr I’Anson says while the Transport Agency has recently invested in a major upgrade of the Saddle Road to boost its resilience and connectivity at times like this when the Manawatū Gorge is closed, the length of the current closure is putting the road under added pressure.

“Given the increased traffic and associated wear and tear on Saddle Road, the Transport Agency has agreed to take over maintenance and management of the Saddle Road from the Tararua District Council for as long as the gorge remains closed, so that any repairs and remedial work are managed and funded by the Transport Agency.”

The Transport Agency expects to have more information regarding the state of the gorge by early next week.