Earthquake infrastructure scenario becoming clearer


The devastation wrought by the magnitude 7.5 quake that struck near Kaikoura will take months and cost hundreds of millions of dollars to repair but work is already well underway.quake

Work crews are making steady progress clearing the numerous landslips and road access will be restored to quake-hit Kaikoura within days, transport minister Simon Bridges says.

He says the New Zealand Transport Agency was working around the clock to fix bridges on a local, inland road – previously known as State Highway 70 – into Kaikoura.

State Highway 7 has already been reopened to allow freight to get to and from the Canterbury region.

Highway 7a to Hanmer Springs is also open, though there is a curfew in the evenings because of debris and landslips.

“The next priority is to rebuild State Highway One and the coastal railway,” Bridges says. While some realignment was likely, “it would still be a coastal route”.

The highway between Seddon and Cheviot was “in an incredibly bad way”, with several slips and roads which had been shifted by the quake and would take several months to clear. “In that instance, we are clearing talking about several months to get that into position.”

Bridges said it would be a long-term rebuild, which meant the transport routes were not vulnerable to future earthquakes.

Seven bridges on the road and rail line needed major repairs, and 14km of the route had been affected by the massive tremor.

Estimating the potential cost of the clean-up, Bridges noted that a major slip in the Manawatu Gorge in 2011 cost $35m to clean up and there were at least seven major slips on SH1.

The NZTA had $500m for state highway repairs and another $200m to $300m for emergency repairs, but the crown would cover the cost if repairs exceeded that amount.

KiwiRail might also need a funding boost for the rail line to re-open either side of the township, Bridges adds. “We are going to get State Highway One back up and running,” he promises. “We are going to get that rail line back up and running.”

Elsewhere, Vodafone, Spark, and Chorus are working together and exploring all options in restoring telecommunications services to Kaikoura.

The earthquake damaged a major fibre optic cable which runs through the region, with six breaks identified so far.

The massive landslides that have decimated State Highway 1 will make repairs and restoration of the cable extremely difficult, and it could take weeks or months to fully restore the cable.

“People in the Kaikoura region are likely to experience degraded telecommunications services for an extended period of time,” the companies admit.

Vodafone, Spark and Chorus are exploring a “range of options” to provide temporary connectivity to the Kaikoura township, including microwave backhaul links to mobile cell sites.

One potential solution involves using Vodafone’s Aqualink cable, which links the North and South Island and passes through the coast of Kaikoura.

This could be “repurposed for temporary use” in Kaikoura, with Spark and Chorus linking to the cable through an additional 50 metres to get to the town.

All three companies now face major risks to back-up services, as another cable that runs down the western side of the South Island could cause serious, island-wide connectivity problems if it was damaged.

Further north, Wellington highways are gradually starting to reopen after the slips and flooding that brought the quake-hit region to a standstill.

On some stretches of highway, NZTA contractors moved median barriers to allow floodwaters to subside in a controlled manner.