It is music to my ears to see the recognition that the key characteristic of our climate is not so much dryness, although there is plenty of that, but variability. Dorothea Mackellar got it so right with her “droughts and flooding rains”. She might well have added “and not much in the middle!” The Millennium Drought followed by record wet years is an excellent recent example.
I continue to contend that in responding to this fact, two words need to dominate our response-conserve and flexibility. In respect to the latter, storages need to be constructed so that under very dry downstream conditions, the option of allowing small flows to pass is available. It requires acceptance of ‘adaptive management’. The variability fact, makes the concept of setting single figure Sustainable Diversion Limits, albeit with adjustment provisions, nonsensical.
Further central issues which strike me are-
- acceptance of the option of using salt water rather than fresh water to maintain levels in the Lower Lakes,
- ensuring Snowy management is required to optimise water conservation as well as electricity generation-particularly with Eucumbene Dam the largest storage in the Murray Darling Basin.