The Murray-Darling Basin (MDB) has the second most variable inflows in the world, and this uncertainty provides complexity in managing the outputs generated from the application of water to either environmental or agricultural production systems. This uncertainty in water supply results in irreversible capital losses (natural, social and economic). During the Millennium Drought the area irrigated in the MDB essentially halved from 1.8 million Ha in 2000-01 to 900,000 Ha in 2006/07 (ABS data various).
We can simplify the environmental outcomes from developing a set of environmental rights and the problems of dealing with supply uncertainty in the following chart.
Well what can we quickly learn.
There’s a second part to this as well. The environmental manager should not be expected to be perfect in allocating water between competing demands. If we lost over 900,000 Ha of irrigation in the Millennium Drought, we have to expect the environmental manager to have to learn some hard lessons in this tough operating environment.
We can represent this learning of how to manage as the scale of outputs being from and depending on the allocation of water. Yes, sometimes we don’t get things right. But over time those hard lessons should be reflected in only the area cC to dD being produced.
So quickly again. This is an uncertain climate and water supplies are not guaranteed especially along the Darling River. We are likely to see big collapses in ecosystems every now and then. However, the ecosystem should be far healthier and more resilient compared to the past.