Quotes from a recent MDBA report, as so often happens, demonstrate how as managers get closer to the practical implementation stage they realise the errors in their theoretical planning.
“Natural flows in the Murray–Darling Basin are highly variable, with water-dependent ecosystems developing and evolving within this flow environment. The high degree of uncertainty over future inflows and the variable nature of environmental demands point to the importance of flexible and adaptive institutional arrangements.”
“The way in which environmental water is managed and how environmental water requirements are specified will influence the environmental benefits and socio-economic effects associated with holding a given portfolio of environmental water. Many of the opportunities to improve outcomes involve environmental water managers using available flexibility to manage their water holdings. Exercising flexibility is likely to require more comprehensive governance.”
The reality is that anyone with a basic understanding of this variability would never have asked CSIRO to come up with Sustainable Diversion Limits without specifically relating them to ever changing flow levels. To argue that the diversion limits are averages doesn’t help as the “spreads around the average” are so large that the averages are statistically meaningless. As a consequence the base plan, on these grounds as well as others, is deeply flawed.
As I have consistently argued when dealing with this massive variability,two words should dominate your vocabulary-conserve and flexibility. It seems that at least and at last, the latter word is emerging. However, given this point and all the problems arising from writing what is basically an environmental plan, as distinct from a socio-economic and environmental plan, it would be best to rescind the Water Act (2007) and start again. This would have the further benefit of distancing the planning from the Millenium Drought environment where many natural drought impacts were falsely attributed to “over-allocation”.