Once water is allocated to consumption, it is very difficult to return it to the environment.
The major lesson from the last 50 years of management of the surface waters of the Basin is that, once water is allocated to consumption, it is very difficult to return it to the environment even when time shows that over-allocation is resulting in severe environmental effects. This lesson is as true for groundwater as it has been for surface water.
In light of these experiences the setting of Sustainable Diversion Limits for groundwater should be approached very cautiously. We have much poorer knowledge of groundwater than we do of surface water. There is a good chance that, as our understanding grows, we will find that we have underestimated the extent to which increased groundwater use will affect ecosystems, downstream surface water users and existing groundwater users. Given this, the draft Basin Plan should adopt a conservative approach and not establish such over-generous Sustainable Diversion Limits which will be difficult and costly to modify later.
Mr Peter Cosier, Dr Richard Davis, Prof Tim Flannery, Dr Ronnie Harding, Prof Lesley Hughes, Prof David Karoly, Prof Hugh Possingham FAA, Mr Robert Purves AM, Dr Denis Saunders AM, Prof Bruce Thom AM, Dr John Williams FTSE and Prof Mike Young FASSA
This Statement has been prepared on behalf of the Wentworth Group of Concerned Scientists in association with Mr Tim Stubbs, Environmental Engineer of the Wentworth Group of Concerned Scientists.