Dam Safety Risk Assessment (Case Study: Flood Risk for Golestan Dam)

In dam construction industry, the safety of dam is one of the most important challenges that should be considered in design, construction and operation phase. Recently, use of quantitative risk analysis, as a useful tool in dam safety risk management, is rapidly increasing. In this paper, first, risk assessment methods in dam safety are investigated and ANCOLD guideline for dam safety risk assessment is detailed. Then, as a case study, safety of Goleastan dam, in northeast of Iran, is assessed considering risk analysis approach for upstream flood hazard. For calculating the probability of failure of dam, the various methods were assessed and finally Event Tree Analysis (ETA), as most commonly method in dam safety risk analysis, was used. The number of life losses due to flooding of Golestan dam break is estimated based on USBR methodology, known as DSO-99-06. Finally, according to calculated risk and comparing with different criteria for acceptable risk, it is obvious that the risk of Golestan dam break due to upstream flood is unacceptable and immediate risk reduction measures are necessary.