Excessive rains may cause floods.
Flooding is an overflowing of water onto land that is normally dry. Floods can happen during heavy rains, when ocean waves come on shore, when snow melts quickly, or when dams or levees break. Areas near rivers are at risk from floods. Embankments, known as levees, are often built along rivers and are used to prevent high water from flooding bordering land. Additional high-risk locations include recent burn areas in mountains , and urban areas from pavement and roofs which enhance run off.