Flood recovery works total $6m+

Flooding along Ashburton Staveley Road saw many properties affected when the Ashburton River north and south branches burst. Photo NZDF

Flood recovery works totalling more than $6m have been carried out to date in flood-damaged points across Mid Canterbury.

But there is still more to be done, with recovery work from last year’s autumn floods expected to reach $8.5m across the Ashburton/Hakatere catchment.

Environment Canterbury (ECan) flood protection recovery manager Shaun McCracken said work had been progressing steadily with the total cost estimated for all repairs across the region was $19.7 million.

“The total regional cost to date for repairs to Environment Canterbury flood protection infrastructure is just over $10 million, of which over $6 million has been spent in the Ashburton/Hakatere catchment,” he said.

The work had been carried out by ECan staff and contractors, with a small number of landowners within the rivers also doing their own works.

“The total cost estimate for all repairs is $19.7 million and we expect about $8.5 million of that to be within the Ashburton/Hakatere catchment,” Mr McCracken said.

Ashburton Staveley Road (pictured), known as the Greenstreet, was among the areas badly hit by May flooding in 2021.

Ecan was working closely with the National Emergency Management Agency (NEMA) who were co-funding the work with around $7.5 million.

During the first couple of months, the focus was on implementing temporary repairs to reduce out-of-river flows from the Ashley River/Rakahuri to the Opihi River.

“Throughout the winter months, we progressed a significant amount of river berm vegetation reinstatement work. This involved relocating trees which had been undermined and washed downstream and replanting them into the berm area to reinstate erosion protection vegetation.

“This is where most of the cost to date has been incurred.

“Throughout the summer months, once the ground conditions were suitable, some of our efforts have shifted to stopbank rebuilds.

He said the two largest stopbank projects in the Ashburton/Hakatere catchment were; the North Branch Ashburton River/Hakatere, upstream of Thompsons Track carried out by Rooney Earthmoving at a cost of around $170k.

Vegetation reinstatement is still to start.

And the South Branch Ashburton River/Hakatere, near Blacks Road, carried out by Grant Hood Contracting (about $175k).

Mr McCracken said significant investment had been required by landowners to restore their own land outside of the river corridor and with autumn rains ahead there were areas of concern.

“All repairs are quite vulnerable to further damage and will remain so for quite a period. This is because the vegetation we’re planting for erosion protection will take time to re-establish,” he said.

“In many places, the re-establishment of a wide buffer of trees is needed and it will take several years before the equivalent pre-flood erosion protection is restored.”

A significant planting programme is planned for this winter.

“We have had great co-operation from adjacent landowners and our contractors have performed marvellously.

“The biggest challenge has been – and will continue to be – continued rainfall events. Much of the work remains vulnerable to erosion and it will take time for us to re-establish a robust vegetative buffer in the river berms.”

All work was due to be completed by May 2023; within two years of the flood.

ECan has uploaded a flood recovery job map on their website so people can see the progress.

It gives an overall picture and shows the location of each flood repair job, colour coded by priority.

Ecan’s flood recovery job map is available for viewing on their website.