On August 11, 2021, one of the most destructive ood disasters occurred in the Western Black Sea Basin of Turkey. The ood resulted in the death of 76 individuals, with an estimated 30,000 people being affected by the disaster. A maximum precipitation depth of 400 mm/day was recorded at one station, indicating that the ood occurred at least during a 500-year rainfall event. During a two-day site visit immediately following the ooding event, damages to infrastructures, water structures, bridges, revetment walls, highways, and residentials were observed in the Bozkurt and Ayancık regions. Based on the observations, the ood wave propagated through the original meandering river bed and oodplain, exceeding the restored river bed capacity. Due to the massive sediment transport and drifting trees, the basements of the structures in these regions were ooded and blocked. The enormous ood ow triggered extensive scouring on bridge piers, building foundations, and revetment walls, eventually causing the walls and bridges to collapse. The collapse of structures blocked the waterway and ampli ed the backwater effect when combined with the sediment transport. The total collapse of the revetment walls in some sections of the stream caused accelerated scouring beyond the foundations of the nearby buildings. Partial damages on the side roads along the river beds were also observed. This paper evaluated the driving mechanism of damages caused by ood ow from hydrological, structural, and geotechnical perspectives. Based on these observations and assessments, recommendations on engineering design guidelines for structures close to the oodplain, such as bridges, revetment walls, and side roads, were elaborated. Emphasis was placed on the ood-resistant design of these structures to develop a comprehensive approach for ood risk management.Flood disaster poses a signi cant risk for the environment and human life (Siddiqui, 2011;Cook and Merwade, 2009). Millions of people lose their lives, and nancial losses are experienced due to oods in various parts of the world. For example, Pakistan, India, and China were severely affected by oods in
