The Bureau of Meteorology chart below indicates the areas of Australia that can be officially classed as drought-affected on the basis of rainfall deficiencies over the last three years, as per precise definitions.

Drought in general means acute water shortage. The drought maps highlight areas considered to be suffering from a serious or severe rainfall deficiency. These classes are assigned by first examining rainfall periods of three months or more for selected places throughout Australia to see whether they lie below the 10thpercentile (lowest 10% of records). The terms serious and severe are defined by:-

• Serious rainfall deficiency:- rainfall lies above the lowest five per cent of recorded rainfall but below the lowest ten per cent (decile 1 value) for the period in question,
• Severe rainfall deficiency:- rainfall is among the lowest five per cent for the period in question.

This provides further confirmation, if any were needed, that, far from being all about drought, the collapse of the Darling system is a direct result of the combination of deplorable over-allocation of ephemeral river flows and the massive and frequently illegal surface-water diversions constructed by agribusinesses in the upper Darling.

The costly experiment has failed;  semi-arid land is not cotton or rice country. Either this madness ends or the Murray-Darling will never again be the bread-basket of the nation.

The Commonwealth must assume responsibility for the management of the entire Basin and especially its environmental health.