Flooding is the overflowing of areas where there is normally no water.
It occurs when, due to intense and prolonged rainfall, the waters of a river or stream are not contained by embankments and barriers and pour into the surrounding area. Or when the sea level rises, as a result of strong winds and low atmospheric pressure, reaching bathing establishments and residential areas.
In urban centres, it is frequent that, due to bad weather, sewerage systems are unable to contain excess rainwater, causing widespread flooding and problems for traffic flow.