The report reveals that both arid and riverine regions are at risk of frequent flooding, albeit for different reasons. In desert areas like San Bernardino and Pima counties, flash floods can occur within minutes due to intense thunderstorms and impervious soils. These floods can inundate roads, underpasses, and low-lying areas, posing risks to residents and infrastructure. In riverine regions such as Allegheny and Alexander counties, flooding is often caused by the overflow of major rivers, which can lead to widespread inundation and significant damage. The study highlights the importance of understanding local flood dynamics, as even areas with low annual rainfall can experience frequent and severe flooding.