An article by Michelle Slater in the Latrobe Valley Express on Engie’s proposal to flood the Hazelwood open cut noted that “the Victorian government has called an Environmental Effects Statement into the Hazelwood Rehabilitation Project. Planning Minister Richard Wynne signed-off on the EES looking into the effects of using 637 gigalitres of water over 10 to 35 years to form a pit lake in the Hazelwood open cut.”
As the mines and power stations close, there can little doubt the preferred option of all the operators is the flooding of the pits, for the simple reason that it is the cheapest. As Slater noted the Engie proposal requires a huge amount of water, and considering our warming climate and the increased propensity to drought, likely to take closer to the longer-term estimate to fill. If other operators like Yallourn adopted this, or a similar, proposal, it can readily be seen that it is unviable.
Even in relatively wet Gippsland water is a scarce resource. Before the closure of Hazelwood the four power stations used more that 20% of Victoria’s annual water consumption. Competing assets like downstream irrigation are already closely looking at the power station’s water allocations. Also stronger river flows would help alleviate the Gippsland Lakes environment that is currently being strangled by increased salinity.
Other options should also be closely considered. The fly ash deposited at bottom of the Hazelwood pit can be used in cement making. At the moment the fly ash with its concentration of heavy metals is seen as a polluter of the water. However, the fly ash may also contain rare earth metals. As far as I am aware, no analysis has been made of fly ash in the valley and it is still considered a waste product. Others have suggested lining the walls of the pit with solar panels and there is also the pumped hydro option.
Dan Caffrey wrote in this blog that for the “Hazelwood brown coal power station in the Latrobe Valley, the required cooling is provided by water from the Hazelwood Pondage. This is 840 ha of water of an average depth of at least a metre. This could be the upper dam of a pumped hydro scheme after the power station closes in the near future. The lower dam could of course be scooped out of the existing Morwell open cut, which lies about 100 m lower than the Pondage. The Melbourne Energy Institute has estimated that a 1000 MW system could be built. This is 1000 MW of instantly dispatchable electricity, available at the flick of a switch.”
Hopefully the EES will consider the details of all this and reject the proposal of turning the Hazelwood pit into a lake. Then consider a range of more climate, and environment, friendly options.