Using Threshold Value Analysis to Assess Options for Environmental Flows Management

Australia's water resource systems are suffering from excessive diversion of surface flows, and adverse effects on the riverine environments are now becoming clearly evident. In 1994, the Council of Australian Governments commenced a water reform agenda to address the continuing decline of riverine health. An ongoing issue of particular concern is the failure to take account of the environmental consequences of water allocations for consumptive use. The capacity of water managers to achieve current reform aims whilst minimising impacts on rural communities will be improved with the aid of new technologies and decision-making processes. This paper describes a framework for examining the effectiveness of using information provided by new technologies to improve the management of river- flow regimes providing benefits to both consumptive and non-consumptive (environmental) users of water. This will be achieved by using a threshold value approach to examine the impact of alternative water management rules. Changes in threshold values represent the opportunity cost of different resource-use decisions, and are examined in conjunction with changes in criteria measuring environmental health to determine the acceptability of the proposed management rules.