A flood is an overflow of water that submerges land that is usually dry. The European Union (EU) Floods Directive defines a flood as a covering by water of land not normally covered by water. In the sense of "flowing water", the word may also be applied to the inflow of the tide.
Floods have large social consequences for communities and individuals. As most people are well aware, the immediate impacts of flooding include loss of human life, damage to property, destruction of crops, loss of livestock, and deterioration of health conditions owing to waterborne diseases.
The Water Page - Flood Control. Flood control has been practiced since ancient times with methods such as reforestation, and the construction of levees, dams, reservoirs and channels diverting floodwater, called floodways. Levees were used by the ancient Chinese to raise the banks of the Yellow River.