Sue Neales article -Farmers Left High and Dry-The Australian June 12-scratches the surface of the utter fiasco which the Murray Darling Basin Plan has become. The Plan is based on the false assumption that the natural environmental impacts of drought are caused by "over allocation" of irrigation water. What the government has been buying from farmers are "entitlements". These "entitlements" grant the holder a share of consumptive water subject to the granting of "allocations". Until "allocations" are granted, the "entitlements" amount to phantom water. So Government ownership has not reduced the number of entitlements, just changed the ownership. The widely claimed "purchase" of water is actually the purchase of entitlements which may or may not, depending on availability, attract an allocation. In other words, it may all be "phantom water", particularly in drought situations.
The reality is that inland Australia is subject to enormous variability in its rainfall and run-off. Establishing single figure "sustainable diversion limits" for each river in the Murray Darling Basin is impracticable nonsense, even if they are averages as the proponents claim. The spread around the average in annual flows is massive. The only way to deal with sensibly limiting extractions where there is huge variability, is some sort of moving share of actual flows.
Sadly, we need to go back to the drawing board, if we are not to seriously undermine Australia's agricultural productive capacity for negligible environmental benefit. We need to re-examine the whole issue, including the enormous waste (to evaporation) of fresh water by attempting to maintain South Australia's lower lakes as unnatural fresh water storages and to keep the Murray mouth open 90% of the time without the assistance of tidal pulses now blocked by the so called barrages.