Makaretu River works protect gas pipeline to Hastings

The HBRC project team assess their work realigning the channel at Makaretu River.

Hawke’s Bay Regional Council (HBRC) has wrapped up work in the Makaretu River protecting the main gas pipeline to Hastings.

In February 2023, Cyclone Gabrielle heavily impacted Makaretu River near Takapau and State Highway 50, shifting the river channel to the left, undercutting the bank, and threatening the Firstgas pipeline. The cyclone also caused considerable erosion to the river’s edge.

It was assessed that the weakened river edge could deteriorate without intervention, and the pipeline would be at risk of damage.

“This work is important to protect the gas pipeline, which is a critical piece of infrastructure for the region,” says HBRC asset management group manager Chris Dolley.

“We thank Firstgas for helping co-fund and collaborating on the successful delivery of this project.”

To minimise future erosion on the river edge, HBRC with support from Firstgas installed a series of rope-and-rail groynes. These structures help to stabilise the gravel and channel along the river edge. After that, HBRC planted willows along the river edge, which will hold the gravel in place. As their roots develop, they will strengthen the bank even more.

Moving the river channel back to its original alignment was a complex task. Heavy machinery was used to install groynes at several locations by the river to redirect water flow. Gravel was also used to bury the pipeline, which increases its level of protection and cover.

Central Hawke’s Bay-based regional councillor Will Foley says he is delighted that this work is finished.

“It’s great to be able to repair some cyclone damage along our rivers, which also protects vital infrastructure to the benefit of the wider Hawke’s Bay community.”

Now this protection work is complete, the river will be maintained as part of HBRC’s ongoing asset management programme.