The level of earthquake damage to the road and rail networks between Picton and Christchurch was unprecedented in New Zealand. The scale of the event and the quick restoration of this economically important narrow coastal corridor, created the great challenges for the recovery project. To restore these transport networks, design and construction had to happen simultaneously, and quickly.
The top priority always has been keeping communities and people safe and reopening SH1 and the Main North Line railway as quickly as possible.
Find out more about the progress on the rebuild of the transport corridor
A challenge has been designing a safe and resilient road and rail line, balanced with minimising the impact on the environment, wildlife and landscape. The greater Kaikōura area is a special part of New Zealand. The NZ Transport Agency, KiwiRail and the North Canterbury Transport Infrastructure Recovery (NCTIR) have been committed to minimising the recovery impact on the environment by collaborating closely with government and cultural departments and organisations.
State Highway 1
More than 200 areas along SH1 were affected by the earthquake. Close to 1 million cubic metres (about 400 Olympic-size swimming pools) of loose material dislodged by the earthquakes fell onto the road and rail line. More than 30 slips were identified south of Kaikōura and nine major slips north of Kaikōura.
Road access was quickly restored to Kaikōura, via the Inland Road (Route 70) and on SH1 south of the seaside town before Christmas 2016. Ongoing works and issues with flooding and additional slips saw travel disrupted on both these routes throughout 2017.
In 2017, while State Highway 1 south of Kaikōura was operating on an open/close schedule, the road remained closed permanently between Clarence and Mangamaunu in the north. Both sections of SH1 (north and south of Kaikōura) opened during the day from Friday 15 December 2017, and then at night from 30 April 2018.
Further details on the work and progress
The alternate Picton to Christchurch route
Post-earthquake, the immediate challenge was diverting drivers from the closed SH1 between Christchurch and Picton to the alternate route along State Highways 63, 6, 65 and 7 (and the alpine Lewis Pass). These roads are narrow and winding in places with single-lane bridges and an alpine pass which can be treacherous when wet and during the winter months.
Vehicle numbers on this route quickly rose four-fold to 4500 vehicles per day, with 1000 of these being heavy vehicles, up from the 350 pre-earthquake. These increased traffic volumes impacted not only on the road, but also local communities. New speeds limits where introduced to improve safety for both motorists and communities, and a $60 million improvement programme developed to upgrade the route so it could handle the extra traffic.
The re-opening of SH1 along the coast means there are two routes between Picton and Christchurch travellers can choose from: SH1 via Kaikōura (allow a minimum of 5.5 hours) and the alternate route via Lewis Pass which remains a viable option with a minimum estimated journey time of 6.5 hours.
The Inland Road (Route 70) between Kaikōura and Waiau
The priority was to restore access to communities which were cut off by earthquake damage and establish safe and reliable alternative routes. The Inland Road (Route 70) via Waiau and Mt Lyford was identified as the best way to re-establish access to Kaikōura quickly.
Crews worked tirelessly to make the severely damaged road safe for general use. This included clearing the road of more than 50 slips, stabilising slopes, repairing damage and building an entirely new diversion road around the highly unstable Whalesback section.
Access through this route was restored within a few days of the earthquake for NZ Defence Force convoys to get through with emergency supplies to Kaikōura which was isolated by the slips.
The route remained fragile and hazardous, with restricted, escorted access only until mid-December when the public were granted unrestricted access to the Inland Road, bringing the first unrestricted road connection back to Kaikōura, one month after the earthquake.
Work is ongoing to maintain this road and keep it open to vehicles 24/7.
Main North Line railway
The Main North Line railway between Picton and Christchurch is a critical part of the transport network for moving freight between the North and South islands. Before the earthquake, about one million tonnes of freight travelled over the line each year. Along the line, nearly 900 sites sustained damage, including tunnels, bridges and embankments. The line was buried under more than 90 slips and landslides. Fifty-nine bridges and 20 rail tunnels were also damaged.
Kaikōura is served by the Main North Line(external link), the northern section of the South Island Main Trunk Railway. The line opened north of Kaikōura on 13 March 1944, while the line south of the town opened on 15 December 1945, the latter completing the full line between Picton(external link) and Christchurch.
Until the earthquake, Kaikōura was served by the internationally acclaimed Coastal Pacific(external link) long-distance passenger train, connecting Kaikōura with Christchurch(external link) to the south and Picton(external link) and the Cook Strait(external link) ferries(external link)to the north.
Further details on the work and progress
The Kaikōura marina
Located in South Bay, just south of the Kaikōura township, the marina provides critical infrastructure for the tourism industry which is one of the largest sources of income for the region.
The earthquake thrust the seabed up by two metres in places, severely restricting access to the marina.
In December 2016, the Government announced a $5.72m contribution to get work underway to restore the marina to full functionality. Tourism operators and other key stakeholders (Whale Watch Kaikōura, Dolphin Encounter, Kaikōura District Council and the Kaikōura Coastguard) further invested in the project for enhancements to allow for expansion and enable access for larger boats.
With the commitment to restore the harbour, the Government passed a bill which made dredging a controlled activity under the regional coastal plan.
Further details on the work and progress
Challenging landscape and harsh weather
The Kaikōura area is often referred to as “where the mountains meet the sea”. The transport network runs along a narrow coastal corridor with some narrow sections where the hill-side hugs the Pacific Ocean. While this offers spectacular views it is also exposed to rapid weather changes. Rebuild work has been interrupted several times because of the weather and seismic activity.
The tropical cyclones Debbie and Cook hit in April 2017. The heavy rainfall resulted in further damage and meant work had to be halted for a number of days as more rocks and material fell from the already damaged slopes.
Working in such a dynamic environment has been a challenge throughout the recovery. With most of the work sites being along the coast, tides and coastal weather have been taken into account for planning work and the safety of workers.
The challenging landscape of the coastal corridor combined with tidal and seasonal conditions mean that constant adjustments have been made to the recovery programme to keep everyone safe and the work on track.
