Set up under federal law in 2004, the commission is working to deliver on the National Water Initiative, a water reform blueprint which includes introducing registers of water rights and standards for water accounting across Australia.

NWC made a submission to the Senate committee last month on its project on the potential local and cumulative effects of mining on groundwater resources.

The commission said the project had highlighted areas where there was significant scope to improve the mine planning and approval process “such as through adapting the environmental assessment processes to better handle those impacts that are cumulative spatially and over time”

Assessing cumulative water impacts in a mining region adds complexity to environmental approvals, as a coal company would have to assess not only the potential impact of its proposed or current operation, but the impact of nearby or adjoining operations.

While it is working towards ensuring the cumulative effects of mining on groundwater are “adequately assessed in the approvals process”, NWC said New South Wales was close to completing aquifer interference guidelines to clarify the assessment of impacts and accounting of water for mining.

Although some farming groups are quite vocal on the threat of mining to water supplies, NWC referred to 2004-05 Australian Bureau of Statistics data on water use in Murray-Darling states in its submission.

Mining accounted for a mere 1.2% of total water use, lower than household use at 9.9%, manufacturing at 2.7% and agriculture at 68%, with grazing and cotton irrigation driving this use.

The data also revealed that coal mining used less than half the water consumed by metal ore mining operations in that time period.

NSW Minerals Council of Australia chief executive Nicole Williams sees no need to alter the current rigorous assessment process.

“No mining project can proceed in NSW without a thorough assessment of potential impacts of a mining operation on the surrounding environment, including surface and groundwater resources,” she said in her submission.

While the committee spent considerable time on BHP Billiton’s Caroona coal project and China Shenhua Energy’s Watermark project, the impact of coal seam gas exploration was also discussed as a risk to underwater supplies, due to drilling depths of greater than 850m and the potential for drilling fluid to contaminate aquifers.