Pluvial flooding occurs when rainfall is so intense that the ground, drainage systems or urban infrastructure cannot absorb or channel the water away quickly enough, leading to water pooling or flowing over land. Unlike fluvial flooding (caused by rivers overflowing) or coastal flooding (from storm surge or tides), pluvial floods happen directly from heavy rain, often in areas far from rivers or coasts. They are sometimes called surface water floods or flash floods. In cities, pluvial flooding can occur when storm drains, sewers or impermeable surfaces (like roads and parking lots) prevent rainfall from soaking into the ground. In rural areas, it happens when soils become saturated and rainfall runs off rapidly into depressions or low-lying land. Pluvial floods happen during or after short-duration, high-intensity rainfall events, which are expected to increase with climate change.
