Environmental Flow Regulator at Chowilla
The Living Murray is Australia’s largest river restoration program, a major step towards ensuring the Murray is a healthy, working river into the future. The initiative involves the Federal, New South Wales, Victorian, South Australian and Australian Capital Territory governments, together contributing more than $650 million to the project. This funding addresses water over-allocation within the Murray-Darling Basin, with an initial focus on achieving environmental results at six River Murray icon sites.
One of the icon sites identified by the program is the Chowilla Floodplain, one of the few regions of the lower Murray not used for irrigation. The Floodplain covers 17,700ha over three states and supports many threatened plants, animals and native fish and thus, has high environmental significance.
The key objectives of the Environmental Flow Regulator was to protect the wetlands, the River Red Gum community and the Black Box vegetation, and to return the floodplain to natural historic conditions. York Civil was the main contractor providing constructability and design advice, pricing and project delivery.
Over two consecutive years, the River Murray saw unprecedented flooding, which forced work on the project to cease. In each instance, York Civil worked collaboratively with SA Water to ensure flexibility in delivery, and in mobilisation to and demobilisation from site.
The project involved the construction of an 85m long 14-bay weir comprising sheet pile cut-off walls and 300 driven piles of 350mm diameter, 6,000m3 of concrete water-retaining structures, and construction of four associated flow regulators. The structures include sophisticated fishways to enable the safe and easy passage of native fish.
The project site included several significant Aboriginal heritage sites. York Civil worked cooperatively with local Aboriginal representatives to ensure cultural sensitivities and the heritage sites were not impacted in any way by construction activities. Aboriginal elders from across Australia visited the site resulting in a countrywide precedent for protection of similar sites in the future.
2015 Finalist – CCF SA Earth Awards (Category 4)