Australian Community Responses to Upgraded Farm Dam Laws and Cost-effective Spillway Modelling

Abstract

Recent attention to farm dams and dam safety in Australia and elsewhere reflects both safety and sustainability issues, and is driven by the fact that since built, many dam safety aspects have changed, e.g. population distributions, meteorological information, estimates of rainfall and runoff, engineering methods, and design standards and techniques. Farmers in Australia have often overlooked the common law obligation to review/design dams in line with current standards because of high engineering consulting costs: this leaves them vulnerable to litigation if their dam fails and the downstream community is susceptible to unacceptable risk levels. The seriousness of this problem has been demonstrated by case studies undertaken in the policy-absent State of South Australia and the policy-driven State of Victoria. In each state, ten hazardous private reservoirs were investigated for spillway adequacy in line with state-of-the-art practice. The investigation follows the release of an innovative Australian developed cost-effective spillway design/review procedure that has been made available and promoted in both states to minimize cost burdens to dam owners and encourage better dam safety management. Recent surveys undertaken in South Eastern Australia to test community attitudes to the procedure and implemented dam safety and water allocation policy in Victoria are also reported. These surveys together with the ‘spillway adequacy’ investigations clearly demonstrate that farmers require more than awareness and encouragement to ensure they look after their dams properly.