Contribution to Dam Break Flood Forecasting Regulations in Croatia

History of dam accidents and failures shows that dam failure caused floods are relatively rare, but can result in significant losses of human lives and material damages. Numerous countries have regulations aimed at decreasing the risks of downstream flooding should a dam break occur. In the Republic of Croatia, the regulation entitled "Guidelines for definition of consequences following a sudden dam failure", enacted in 1974, is still in force. The guidelines are very restrictive, based on the assumed total, instantaneous dam failure. Under such assumption, the flooded area is relatively large, restricting the use of the area downstream of dams and thus preventing development. The new guidelines, based on a more realistic assumption relative to dam break, are in preparation. These guidelines shall define a new approach to positive wave front simulation and risk analyses methods. The paper presents both the experiences with the regulation in force and the proposed new guidelines.