$881m Upgrade For Dam?

20170404wivenhoe3 — Wivenhoe Dam’s wall could be raised by either two metres or four metres by 2030, according to a report in Tuesday’s Brisbane Times (Photo: Somersetpedia.paul)

April 5, 2017

by Anne Miller

Wivenhoe Dam wall could be about to be raised by either two metres or four metres, if news reports published on Tuesday night are correct.

The Brisbane Times is reporting that dam operators Seqwater have a major upgrade of the dam “in the pipeline” which could cost taxpayers up to $881 million.

Raising the dam walls four metres would increase the capacity of Lake Wivenhoe by almost a million megalitres, according to the Brisbane Times.

Also included in the upgrade would be a third spillway at the dam wall and the removal of the emergency “fuse plug” spillway.

This is not the first time the prospect of raising the dam wall to increase capacity and improve downstream safety has been canvassed.

In 2014, the then-LNP State Government completed a long process to identify flood mitigation options for the Brisbane River catchment.

Potential new dam sites were investigated – as many as 39 – which included proposals which could have affected some South Burnett residents.

A prefeasibility investigation then developed a shortlist of three options which were released in December 2014:

Increasing the flood mitigation ability of Wivenhoe Dam by raising the dam wall;

A new dam on the Brisbane River upstream of Linville; and

A new dam on the Lower Warrill Creek near Willowbank

The prefeasibility report tested various outcomes for raising the Wivenhoe Dam wall from between 1.5 metres and eight metres, as well as raising the existing spillway and installing a second emergency spillway.

Sadly for the dam proposal, the State Election was held in January 2015.

Not long afterwards – in February 2015 – the new ALP Government put on hold the dam proposals at Linville and Willowbank, leaving the Wivenhoe Dam wall adjustment as the only option.

Nothing has been reported since, until Tuesday’s night claim in the Brisbane Times that the wall will be raised by 2030.

The newspaper also claims that as well as flood mitigation, the upgrade is necessary because Wivenhoe Dam has not met national safety standards since 2002.