Ensham levees do the trick
IT was a nail-biting time for Ensham Resources last week when its mine east of Emerald received 200mm of rainfall in less than 24 hours.
But the site’s upgraded levees, built to withstand a one-in-a-thousand flood event, held.
Flooding was minimal at 3000 megalitres, a fraction of the 160,000 ML that inundated the site in January 2008.
Despite being shocked at the intensity of the rainfall last week, Ensham Resources chief executive Peter Westerhuis said the site was “under no threat” of flooding.
The excess water has impacted on production however, submerging the coal and bringing operations to a standstill.
Mr Westerhuis said the company was anxious to start releasing water.
“We want to take advantage of the high flowing river to return the water, from the sky, back into the river system,” he said.
Mindful of the criticism received in 2008 after its water release caused elevated salinity levels in the Nogoa, Mackenzie and Fitzroy river systems, this time Ensham is determined to do things right.
The company has applied to the Department of Environment and Resource Management for a Transitional Environmental Program, which will authorise the controlled release of water from the mine pits.
“Under the TEP terms we can only discharge the water while the river flow is greater than 10,000 megalitres a day,” said Mr Westerhuis.
“It is estimated that the river will be fast flowing for the next 28 days, which is the time limit we have. Once we are releasing water at 100ML a day, the river will flow at 70,000ML per day, so there will be an untraceable impact on the river.”