December 2023 update

Here’s a snapshot of what’s happening onsite and behind the scenes.

Earthworks

A total of 6.3 million cubic metres of earth have been moved since construction began in January 2021.

Since the last update, Fill 13 (below) has been completed, a significant milestone for the earthworks programme. Fill 13 is in the middle of the project and before it was completed, this was a real pinch point, preventing machinery from moving between zones.

The last remaining major fill is Fill 18 towards the Woodville end of the project, with about 19,000 cubic metres left to go.

Earthworks teams have made good progress through Zone 3, where most of the remaining earthworks areas are. Bulk earthworks are on track to be completed by February 2024, after which the final trim will be performed before pavement construction begins on those areas.

Structures

At Parahaki Bridge over the Manawatū River, construction of the superstructure (bridge deck) is well underway, with three pairs of concrete sections completed. These are being constructed using the form traveller, which sits on Pier 1. At Pier 1, a second form traveller will be installed in early 2024, enabling the team to construct more segments of the bridge deck. At Pier 3, construction of the pier table is underway.

Over the river at Eco-Viaduct, all 42 beams are now in place on their piers on this 300-metre-long structure over an ecologically sensitive wetland. One section of the bridge deck has been poured, with 10 more to go. The second section will be poured early February. Four of six pier heads have been poured, and the MSE walls are complete.

In Zone 4 at Mangamanaia Stream Bridge, we saw the arrival of the super tee beams in early December. All 11 beams have now been placed, and construction of the bridge deck is underway.

Landscaping

The final five thousand plants (raupō) for the season have been planted at the western side of Eco-Viaduct. Many of the raupō in this area were removed to allow initial access into this site, so these have been placed as mitigation planting with another several thousand to be planted next season.

Spring has seen the teams swing into maintenance mode, with release spraying continuing around newly planted sites to protect the plants from being overgrown by pasture grasses.

If new plants are left to be, these grasses grow above the height of the young plants and then smother them. Mulch placement has commenced again with most zones being worked in.

The new year will see tree pits installed in Zones 2 and 4 prior to mulch placement.

Control of both plant and animal pests continues to be carried out by our iwi partners. The rabbit population along the alignment is declining – we know this because we can see our native grass plantings now thriving.

While we don’t do any new planting over spring and summer, these seasons are used to prepare the ground for the upcoming winter plantings. Next winter will see another 500,000 plants placed.

Pavements

The pavements team is gaining some momentum as the earthworks teams are handing over larger areas and the weather is improving slightly. A total of 20% of subgrade (the layer of earthworks before pavement aggregate goes down) has been handed over to date, all of which is in Zone 2.

The completion of Fill 13 also carries significant value to the pavements team, as this allows access from Zone 2 to the main aggregate hardstand in Zone 3.

January 2024 will see the team starting pavement construction in Zone 3, working back towards Cut 13 where they are currently finishing up.

Between January and March next year, another 3 pavement teams will be joining the project, working in Zones 3 and 4.