Some thoughts from FOMS Patron, Lynn Brake
Over the past few months the media has been filled with information about the effect of the current drought on primary producers, especially in the drier parts of Australia. In most of the country underlain by the GAB the effect of the dry weather has been exceptionally severe. Water from the GAB is the only water to sustain life and supports all human activity in much arid and semi-arid parts of Australia. There is no alternative source. More than 120 towns, hundreds of pastoral stations, mining and petroleum industries and visitors rely all on GAB water. There are more than 34,000 water bores in the GAB. They support more than $12bil in production and have a replacement cost of more than $4bil. There are more than 6000 GAB springs. These and the groundwater dependent ecosystems that they support are sites of immense cultural and natural value. The GAB is one of the largest artesian Basins in the world and unquestionably Australia’s most important groundwater resource.
Recent research by Geoscience Australia demonstrates that recharge rates into the GAB from rain along the dividing range is as much as 90% less than indicated by previous studies. This means that we are effectively ‘mining ‘water from the GAB. Pressure is naturally falling; this is being accelerated by water extraction through bores. As a result, the judicious use of GAB water is essential to eliminate any waste and sustain the benefits that we value from the GAB. The springs will be affected and many even dry completely with just a small pressure drop. Pressure is not the only issue however. As islands of wet in an otherwise sea of dry springs attract animals from a great distance to water and feed on the vegetation in and around the spring vents. The impact of these animals risks the natural and cultural values that springs support.
So far the risk to overexploitation of the GAB is being quite well managed. If we are judicious and diligent and work cooperatively together to manage the risks to artesian pressure and maintain the surface structures around springs and the Ecosystems that they support the GAB will continue to provide water and benefits for people, industries and spring fed ecosystems for many years to come.