The Department of Water’s proposal to reduce salinity levels in Wellington Reservoir has been deemed the most prospective option after an independent review.
However, the report also highlighted the need for a full feasibility study to be undertaken to assess the costs and benefits of the department’s option
Water Minister Graham Jacobs said the State Government had commissioned an independent assessment of different plans for improving the quality of the reservoir’s water so it could be better used by the region’s industry and agriculture.
“Industry and agriculture require big volumes of fit-for-purpose water and to continue to support these sectors and the regional economies relying on them, we need to be able to optimise existing but unusable water,” Dr Jacobs said.
“When we came into Government there was a lot of input from different groups with plans to achieve this.
“To weed out the fantasy options and focus on the practical, the Government commissioned an independent review, which looked at 18 different proposals before narrowing them down to a short list of four and a final conclusion as to the most effective option.”
Previous Department of Water programs implemented in co-operation with other agencies and landholders, including tree planting in catchments, helped reduce salinity levels of Wellington Reservoir from a high of 1300mg/l to the current average of 900 mg/l.
“This is still too high to be useful for the growth and diversification of this rich agricultural area, where industry needs high-quality fresh water and agriculture requires lower salt levels to make the land more productive, allowing more types of crops and pasture,” the Minister said.
“Funds for the initial project to reduce salinity to about 650mg/l in the reservoir are in place thanks to the State and Federal governments. Planning and approvals for the project are continuing and a tender has been advertised.”
While the study has helped clarify the most appropriate option for desalinating Wellington Dam, work is still needed to determine if this is the best option to supply water for the region.
The next stage involved working with the South West Development Commission to determine the overall demand for water in the area and the various alternatives to supply that demand.
The department’s option is one alternative to be considered.
Dr Jacobs said the supply of new fit-for-purpose water would make a substantial difference to the South-West’s security of supply but it was important the Government was confident of further works being economically viable and cost effective.
The summary record of the independent review of options to reduce salinity in Wellington Reservoir paper by consultants KPMG with Worley Parsons can be viewed at http://www.water.wa.gov.au
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