More work needed on dam risk

31st July 2019

Source: 1233 ABC Newcastle | By: Ben Millington | Posted: July 31, 2019

A State Government-commissioned review has found the risk of a NSW coal ash dam wall collapsing in an earthquake is "reasonable", but more work to determine the level of risk is needed.

The earthquake risk forced the sudden closure of the popular Myuna Bay Sport and Recreation Centre at Lake Macquarie in late March this year, when Origin Energy first raised concerns about the stability of its nearby Eraring power station's coal ash dam in the event of a major earthquake.

Geoscience Australia said the risk of an earthquake of magnitude-5.7 or above was a one in 5,000 year event or longer.

In the wake of community backlash over the Myuna centre's closure, the State Government commissioned engineering consultancy group SMEC to review the Origin report that first identified the earthquake risk.

"I commissioned an independent peer review of the technical advice the NSW Office of Sport relied upon when making its decision to close the centre," a statement from Sports Minister John Sidoti said.

"The independent reviewer has concluded the assessments of risk in the original reports were reasonable, and the closure of the Myuna Bay Centre, as a means of risk reduction, was consistent with NSW Dam regulation policy in relation to such risk, or potential risk.

"The independent reviewer has also recommended further work be undertaken to increase the understanding of the level of risk in greater detail."

Mr Sidoti said the additional risk assessment was already underway.

He said he should have the information needed to make an "informed decision" about the Myuna centre's future by early September.

Earlier this month the ABC revealed internal government emails showing that the NSW Dam Safety Committee initially warned the government against the immediate closure of the Myuna Bay centre, citing the lack of an immediate risk.

The region's independent state MP, Greg Piper, said he was frustrated by the latest review, because the actual degree of risk to the Myuna centre had still not been determined.

"It concludes that the dam wall would likely fail if a major earthquake followed a heavy rain event, and that of course would have a catastrophic impact on Myuna Bay, and on anyone driving along Wangi Road, and on the lake itself," he said.

"But it doesn't tell us the chances of that happening, and that is what I and the community have been asking since it was abruptly closed and evacuated without warning.

"It is clear that the risk is incredibly low … there is a degree of risk in everything we do, but we don't shut everything down or lock everyone up in indoors."

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