Highway work heads into winter construction season

Tuesday, 1 June 2021

Earthworks at the Ashhurst end of the new highway are continuing as the project enters the winter construction season.

Construction of the new highway between Manawatū and Hawke's Bay is moving into its winter phase, as the route's footprint becomes visible.

At the Ashhurst end of Te Ahu a Turanga Manawatū Tararua Highway a new bridge is emerging over the Manawatū River.

It's a temporary structure that will allow equipment and workers to build the 300-metre Parahaki Bridge over the river from the central pier outwards.

Around that pier has sprung a cofferdam, which will keep river water away so construction can continue.

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Over the river pine trees have been removed where another 300-metre bridge taking motorists over sensitive wetland will be constructed ahead of a steep climb up the southern Ruahine Range.

Construction began in January and the $620 million new highway, replacing State Highway 3 through the Manawatū Gorge, is due to be ready by the end of 2024. The old SH3 has been closed since a landslip fell in April 2017.

A temporary bridge will allow machines and workers to build the 300-metre Parahaki Bridge over the Manawatū River.

Waka Kotahi NZ Transport Agency project spokesman Lonnie Dalzell said an application to do construction work over winter, out of the normal season, had been accepted.

“We need to show the Horizons Regional Council that we can continue to do low-risk work.”

Such work included to the bridges from the river bed, anything that didn't cause extra sediment to run into waterways.

Now the trees had been cleared near the second bridge, Dalzell said project alliance workers would do further geotechnical investigations to help refine the structure’s design.

The project was expected to include the pouring of about 6000 cubic metres of concrete. This week the first 60cum went down on an underpass at the western end of the new road.

That figure paled into insignificance compared with the 250,000cum of material that would be moved during construction, including on the massive project to fill a gully for the climb above the bridges.

Work over the winter on that site would slow due to the wet ground, as expected.

But there's still plenty happening, including building an access track around the wind farm area.

“It's also the season when we do our planting. We've kicked off our ecological planting and pest control.”

This winter it’s expected more than 100,000 native plants will go into the ground.

Dalzell said about 160 people were working on the project. It is expected to peak at about 300.

The new road will take about 13 minutes to drive, much shorter than the Saddle Rd.

♦ The project alliance office near the Manawatū Gorge walk car park at the Ashhurst end is open on weekdays from 9am-4pm for people with questions or seeking information.

Correction: An earlier version of this article incorrectly referenced the coffer dam as a copper dam. (Corrected, June 2, 11.40am)