A debris flow area north of Kaikoura following clean-up work after ex-cyclone Gita – the channel built under the road is one of many new features that aim to reduce the necessity of road and rail closures in the future
Ex-cyclone Gita clean-up works in Kaikoura wrapping up
Resilience work on Kaikoura’s coastline affected by ex-cyclone Gita is close to wrapping up, two years on from the extreme weather event.
On 20 February 2018, ex-cyclone Gita wreaked havoc on the earthquake-affected coast, bringing down 60 slips along the Kaikoura corridor from the Hundalees to just south of Clarence.
Waka Kotahi NZ Transport Agency, KiwiRail and the North Canterbury Infrastructure Recovery (NCTIR) alliance worked swiftly to restore access north and south of Kaikoura. Over 300,000 cu m of material needed to be cleared from the road and rail in order to get the transport networks back up and running, which was done by 5 March, but ongoing work has continued to make it safe and resilient.
“The damage that ex-cyclone Gita caused can’t be underestimated,” says Colin Knaggs, Transport Agency manager for NCTIR. “Our teams were already working on clearing material from the earthquake and this was a huge setback.”
After assessing the damage, engineers were overall pleased with how the existing infrastructure had handled the extreme rainfall, but ex-cyclone Gita exposed additional erosion paths where significant volumes of natural debris remain in the hillsides and will continue to wash down in heavy rain events.
“At major Gita-affected sites, engineers have focused on increasing the capacity of infrastructure to create easy-access, low-maintenance design solutions. The newly-widened debris flow bridges, culverts and strengthened retaining walls aim to reduce the necessity of road and rail closures in the future. These types of solutions contribute to making the Kaikoura transport corridor safe and resilient.”
NCTIR has a full workload planned through to June, when work will begin to wind down, with the completion of seasonal works expected in late spring 2020.