Rising water levels in Yallourn’s West Field open cut mine are nearing capacity, as owner/operator TRUenergy struggles to implement its water pumping response.
While additional flows from last week’s rain surge in the Morwell River have eased, water continues to flood into the disused section of the mine at more than twice the rate it is being pumped out.
“It’s an ongoing challenge; with more water coming in than what’s going out, and with water levels dramatically higher now, we have to stop regularly to clean (pump) filters, so (we) are not pumping it constantly out,” TRUenergy spokesperson Carl Kitchen said.
Less than two weeks ago, the company predicted it had another 30 to 40 days’ worth of runoff capacity in the West Field pit; however, last week’s floodwaters significantly shortened that prediction.
TRUenergy estimates put current inflows from the Morwell River at 800 megalitres per day, while its pumping operation, which is directing the water through temporary pipelines to the Latrobe River, is currently working at 300ML per day.
Mr Kitchen said a decision to re-divert the water back into the East Field mine, where the first breach in the levee banks occurred earlier this month, was due to be made by the end of this week, however it would then only be a matter of time before water levels reached the coal supply conveyors, which would have to be relocated.
“Once we make a decision to run the water into East Field, the lower conveyors will need to move into higher ground – there is one or two which will need to be moved,” Mr Kitchen said.
The mine is continuing to supply coal at a limited capacity to the power station via a single conveyor belt and a 10-strong internal trucking operation, maintaining a 20,000 tonne supply reserve, worth 70 hours of single-unit generation.
Mr Kitchen said the company did not expect to have additional generation units running until mid-July, when it expected to clear a second debris-filled conveyor tunnel underneath the Morwell River diversion.
Current efforts to install a medium-term 1.6 metre diameter pipeline through the mine, which would re-direct the entire flow of the Morwell River, was due for completion late July.
Mr Kitchen confirmed the company was already making moves to implement a complete reparation of the Morwell River diversion as the long term solution of the breach.
“Once we can get the major piping system in place, that then allows us to finish the a repair of the Morwell River diversion, which will take months to complete,” he said.