Water Supply Danger !

Adding to the uncertainty about whether we will have enough electricity to keep the lights on this coming summer, a new threat is emerging to our water supply.   A report by consultants PSM has revealed massive cracks in the earth above areas being mined for coal at the Dendrobium mine near Wollongong.

It is important that nothing interferes with the natural flow of water on the land surfaces because we rely on this to fill the water storage  rivers and lakes that form our water supply.  As a result, a vast area surrounding the city of Sydney is designated a " catchment " area and is subjected to activity control.

What is alarming about these newly discovered cracks is that they pose a danger to both Cordeaux reservoir and Avon reservoir, and both of these constitute the water supply for the city of Wollongong.  Sydney Water is the coordinating authority for the integrated network of dams and rivers that provide the drinking water for the greater Sydney area.

The problem with these newly discovered cracks in the ground is that they will redirect the natural water flow and may upset the water level in the sensitive upland swamps that hold balancing water.  The outcome is unknown, but anything that threatens the water supply must be taken seriously.

What seems to be the issue is longwall mining.  This is an efficient way of mining coal with machinery but it leaves behind vast empty tunnels where the coal used to be.   The earth above mining areas is subjected to " settlement " and home building codes allow for this to mitigate damage.  Usually, this settlement is both gradual and minor and happens over a long period of time.  The fact that deep cracks have appeared indicates that this settlement is both violent and short term.

The Dendrobium mine was originally owned by BHP Billiton and has been spun-off to subsidiary  South 32.   It was recently granted approval for more longwall mining without submitting a water impact statement.  It provides employment for four hundred miners and the future of the mine will obviously have an impact on employment in the Wollongong area.

The coal from Dendrobium is high quality and sought after overseas but we have a high number of massive new mines coming online and most of these are open cut mines.  The Wollongong mines are deep shaft operations and require the use of longwall equipment to be commercially viable. The question arises as to whether longwall is still an option in catchment areas where the holes it leaves may endanger the water supply ?

Obviously, the first requirement is to evaluate what damage has already been done, and what needs to happen to mitigate further damage.  The outcome will be politically controversial !