Tool for decision-making regarding general evacuation during a rapid river flood

•We propose a tool for a general evacuation decision during a rapid river flooding.•If this tool had been applied during the river flood in Obrenovac, Serbia in 2014, it would have saved 13 lives.•Our tool is simple and universally applicable.

ObjectivesTo propose a simple and effective tool for decision-making regarding general evacuation during a rapid river flood.Study designVirtual testing of a tool in a real event.MethodA four-component tool was applied to build an alternative scenario of the catastrophic river flood in Obrenovac, Serbia, on May 2014. The components of this tool are: (1) the amount of precipitation above the 95th percentile of all previous measurements; (2) upstream river discharge above the 95th percentile of all previous measurements; (3) upstream river level above the 95th percentile of all previous measurements; and (4) worsening of the hydrometeorological situation in the following 48 h.ResultsIn the early morning of 16 May 2014, a rapid river wave flooded 80% of the Obrenovac territory. There were 13 deaths due to drowning. Application of the study tool shows that these lives could have been saved, as the score to recommend general evacuation was reached 1 day before the flooding. The application of this tool to two previous great floods in Serbia shows that the score to recommend general evacuation was reached either 1 day before or on the onset of flash flooding.ConclusionsDue to its simplicity, this tool is universally applicable to facilitate decision-making regarding general evacuation during a rapid river flood, and it should be further tested in future similar catastrophes.