Contractor John Holland has won an AUS$50M (£2.77M) contract to raise the height of the Chaffey dam in New South Wales.
The contract, awarded by New South Wales State Water Corporation, involves raising the dam wall with a reinforced earth embankment and 1.8m parapet wall, and raising the reservoir’s “morning glory” spillway.
According to John Holland New South Wales business development manager Gary Pullar, the raising of the morning glory spillway, which will be carried out over the water, will be the hardest part of the work as the team focus on making sure the water remains unpolluted.
“What they’ll have to do is build a protective structure around it, so people have got a platform to work on, and then they’ll do it quite slowly and painstakingly, putting in the formwork and erecting the structure,” said Pullar.
The project will increase the dam’s storage capacity from 62,000M.l to 100,000M.l to secure the water supply for the city of Tamworth and Peel Valley.
Work is expected to take 18 months but may be delayed by heavy rainfall.