Two large pumps were delivered to Central Deborah Goldmine yesterday, integral to plans to bail out the tourist attraction from rising groundwater.
The future of the tourist mine was in doubt after Unity Mining turned off its groundwater pumps earlier this year, and water has continued to rise underground since.
Initial predictions tipped the mine would be underwater this month but mine manager Karl Penrose said the water rate had slowed and the pumps probably would not be needed until December. “What we think is happening is there’s some old workings on the Sheep’s Head reef and they didn’t have as much water as we expected so they have been filling up,” Mr Penrose said.
“We couldn’t assume they were empty so that wasn’t factored into calculations.”
Mr Penrose said the pumps would still be set up as quickly as possible, 260m below the surface of Central Deborah, but would not need to be switched on until water reached them.
“We’re currently looking at about mid-December now but that is a very rough estimate,” he said. The two submersible Grundfos SP95-20 bore pumps – delivered by Midland Irrigation – have been funded by the state government, Bendigo Trust and the City of Greater Bendigo.
The pumps are about 5.3m long, weigh 450kg each and will pump 80,000 litres of water per hour. “The pumps are much larger than they need to be in case, say, one fails and the other has to pump the water itself,” Mr Penrose said.
“We will have a zone where the water will be able to rise up before the pumps turn on and drain it down. That will be a 24-hour cycle basically.
“We want them to be working mostly at night so we can hopefully use off-peak power.”
But Mr Penrose said more would need to be done in the future to ensure a long-term solution to water problems at the mine and in Bendigo.
“This water is a Bendigo problem, not just a Central Deborah problem, it’s just that we are dealing with the problem here,” he said.
“It will rise up to the surface not just in this mine but other shafts and would spill over into creeks bringing a nasty rotten egg smell.”