CSIRO releases review of irrigation scheme modelling

The water modelling that would have been used to underpin a heavily debated multi million-dollar irrigation scheme in the South West is scientifically outdated, an independent review has found. The State Government today released the findings from the Commonwealth Scientific and Industrial Research Organisation’s review into modelling for the Southern Forests Irrigation Scheme, which had been conducted four years ago. The scheme would involve a 15GL dam being built 3km east of the middle Donnelly River, near Manjimup in the State’s South, which would capture flows to supply water to more than 100 farms through a 250km pipe network. An independent review by the nation’s peak science body was called earlier this year after growers raised concerns with Agriculture Minister Alannah MacTiernan and an online petition against it garnered almost 10,000 signatures. The review, which was released this afternoon, found the Donnelly River model was based on water modelling “methodologies” used at the time, but the scientific understanding of climate change and its impacts has since continued to evolve. It states that in its present format, the model “could not be considered fit for purpose.” Ms MacTiernan said the review would help in paving a path forward for the irrigation scheme. “The Department of Water and Environmental Regulation is now working in consultation with CSIRO and is reviewing the report, with a preliminary assessment of its implications to be provided in coming months,” she said. “However, it is clear this will result in a reduction in water available to the Southern Forests Irrigation Scheme. “This independent review provides an important path forward to determine the future viability of the proposed Southern Forests Irrigation Scheme. “Our ultimate aim is to deliver reliable water so the farmers can continue to feed our people, and we need to deliver a viable, credible project to do that.” DWER is now expected to work with CSIRO to review the report, with an assessment of its findings due to be provided within “coming months.”