Waiau River washout

It’s taken QRS six months to rebuild a portion of Waiau River bank after significant washouts compromised the riverbank near the old water intake on State Highway 38 in September last year.

Two significant floods caused the displacement of hundreds of cubic metres of riverbank, and after winning the contract from Wairoa District Council, QRS has been working on the repair since February 2019.

Interlocking steel sheet piling has now been driven into the bank to support the erosion prone area. The piling has segments with indented profiles that interlock and form a strong solid wall increasing resistance to bending.

A backfill wall will be constructed up the bank and once finished, the area will be hydro-seeded and planted for slope stabilisation and erosion control.

Early on in the construction project engineers had to use specialist divers from Wellington to cut away old sheet piling under the water which added significant time and costs to the project.

An old intake tower forms the background for the four QRS staff who work there most days. The vertical concrete structure was used for capturing water from the river below and conveying it to Wairoa’s water-treatment plant further along the road at Frasertown.

With new water intake facilities a little further down the disused tower is now a home for noisy pigeons!

15 July 2019

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