The present contribution aims to give an insight into the main terrestrial and marine processes leading to delta flooding in the case of the transboundary Evros delta, located at the microtidal NE Aegean Sea, on the basis of recorded flood events in the Evros deltaic plain. The prevailing weather conditions at the onset of the event, along with sea-level rise above the mean state, portray the mechanism for the development of compound flood events and subsequent riparian flooding. This system blocks the riverine water’s seaward exit, resulting in the flooding of the lower deltaic plain. The river discharge is recognized as a secondary factor acting mainly toward the persistence of the events. Several limitations restrict the quantification potential of the relative contribution of the key factors to the development, onset, and duration of a flood. Mitigation of the impacts of such flood events requires intercountry cooperation and a management plan based on a network of environmental monitoring.