FEARS have been raised among residents about a tailings dam planned as part of a proposed mine near Corryong.
A meeting will be held tonight over Dart Mining’s Mount Unicorn project, which will target molybdenum, copper and silver deposits.
Nariel Valley resident Wayne Potocky said the company’s own documents revealed the mine would produce 200 million tonnes of tailings.
“Our concern is that we’re going to have a 300- hectare tailings dam, which when you look at their history aren’t particularly comforting,” Mr Potocky said.
“That’s because of the consequences of what happens if they breach.”
Mr Potocky said people were also concerned by the impact of the dam on waterways.
He said substantial rain in the upper valleys could create a 10-fold increase in creek flows, which in some areas could cover the valley floor in the Nariel area.
Residents were told last week that the company wanted to take four gigalitres of water out of the valley every year.
But Mr Potocky said Dart’s submission to the Victorian government revealed another 15 gigalitres a year in processed water would be needed for the project.
“It will definitely have an incredible effect on the flow rate of this creek,” he said.
Another concern was the sulphites in the tailings that, if there was seepage, would turn into sulphuric acid that could get into waterways.
Managing director Lindsay Ward said Dart Mining had been “very open and transparent” about its plans for Unicorn.
“One of the aspects of mining is when you dig something up you have to put the waste material somewhere,” he said.
“What we’re looking to do is take that waste material, which is basically crushed-up rock, and put that into a tailings dam and to store that material safely out of harm’s way.”
Mr Ward said the design of the tailings wall and the plethora of government regulations meant “the dam wall is there to stay, it’s not going to breach”.
“The tailings dam will be designed to withstand a one-in-1000 year event, when these are usually designed for one-in-100,” he said.
Mr Ward said the design would include a spillway to cater for anything unexpected.
“Given the chemicals we use in the tailings are inert, the release of that water into a system that is just amassed with water would have absolutely no effect on the ecology at all,” he said.
The meeting will be at the Thowgla Hall at 7.30pm.