Six months after the completion of a three-year progressive rehabilitation program, monitoring at Jutts Crossing, just upstream of Marhnyes Waterhole, indicated a stable water loss of less than 5%, and actually indicated a small gain in water flow.
General manager of sustainable development Wendy Tyrrell said the company was committed to ensuring that the sections of the Georges River affected by mining would be rehabilitated to a standard satisfactory to the government approval the company had been granted to mine in the area.
The standard is based on achieving river health as close to pre-mining conditions as possible.
Tyrrell said before the rehabilitation began, 40% of water was being lost out of the pool at Marhnyes Waterhole. However, that had dropped by 15% after the first stage of the rehabilitation.
“Since the second grouting, the water loss has remained at less than 5 percent and in actual fact recent weekly monitoring has revealed a small gain in the flow, which is likely to indicate small groundwater inflows,” she said.
Tyrrell said the works program – which began in March 2003 after sufficient time had passed for subsidence to reduce – demonstrated that the company’s rehabilitation goals could be achieved. “Importantly, the rehabilitation ensures that the pools do not dry out in times of low flow in the Georges River,” she said.
“This is clearly demonstrated by the water flow monitoring data collected since the rehabilitation has been completed.”
She said the company was pleased with the results and was committed to continuing to monitor the work while mining coal in the most sustainable way possible.
“The company has spent more than $3.32 million on mitigation and rehabilitation work on the Georges River and has made a substantial commitment to responsible environmental management in that its current plans do not propose longwall mining under the Georges River.”
Following extensive campaigning from a number of environmental groups, Illawarra Coal has also extended that commitment to the Cataract and Nepean rivers, with current plans excluding longwall mining directly beneath these rivers.