Flood Management Methods

Levees

• The ancient Chinese used levees to raise the banks of the Yellow River so the water channel would deepen and prevent overflow from flooding surrounding areas. In Europe, levees were used on the Danube and Rhine rivers during the Middle Ages. Levees are currently used on bodies of water such as the Mississippi River and Lake Okeechobee. Made of soil and earthen material, levee embankments prevent flooding because they raise the sides of waterways and riverbanks to greater heights.

Dams

• Beavers make natural dams out of tree branches and limbs, while engineers create enormous concrete structures. Some dams are built to store water, create power and provide irrigation water, while others are built exclusively for flood control. Flood control dams typically are built on stream headwaters and are designed to release excess floodwater downstream in the event of heavy rains. The key is releasing excess water at the appropriate time.

Sandbags

• When levees and dams fail, sandbags are commonly used to control and prevent flooding. Filling sandbags with sand or soil is usually more efficient with two-person teams, and overfilling a sand bag is a common mistake, according to a report on flood-fighting methods by the State of California Department of Water Resources. In fact, burlap sandbags should only be approximately 1/3 full. When flooding is expected in some flood-prone areas, sandbags are often placed on top of levees.

Reforestation

• When rural and suburban areas sprawled around urban centers in the 1960s, 1970s and 1980s, natural habitats and environments that provided flood control were destroyed. Many urban planners and environmentalists now promote planting native trees and species in these areas to decrease flooding. Other techniques to help restore a natural flood-protecting environment include crop rotation and contour plowing.