Management of regulated river systems in NSW, Australia for drought

Australia is the world's driest continent and streamflows are more highly variable than anywhere else (McMahon and Mein, 1986; Finlayson, et al, 1986). Together, these factors mean that droughts in Australia are frequent and severe, and may persist for several years. For management purposes in Australia, drought is broadly defined as a severe water shortage typified by a prolonged period of rainfall deficiency (Drought Policy Review Task Force, 1990b). Primary producers generally refer to drought as occurring when the available rainfall over a period of time is insufficient to generate adequate plant growth and there is a consequent reduction in agricultural production. In the community the perceptions of drought vary widely. Many regard it as a natural and recurring phenomenon that should be planned for and accommodated, while others regard it as a freak of nature and a disaster (Drought Policy Review Task Force, 1990b). Given that droughts are frequent and severe, government is promoting a more self reliant approach to drought management (Drought Policy Review Task Force, 1990a). It is also promoting the concept that drought is a part of the natural variability of climatic conditions, not a natural disaster, and that this variability needs to be taken into account, through risk management strategies, in the operation of agricultural and other rural enterprises. In New South Wales there have been ten drought periods in the 20th Century covering all or most of the state, ranging in duration from 3 to 12 years (Department of Water Resources, 1993), of which the latest was from 1992 to 1995. The situation was similar in the 19th Century also.