Floods’ refreshing benefits
Floodplains, the broad flat areas near rivers and lakes, act like natural sponges. They allow large volumes of water to be stored and slowly and safely released down rivers and into the groundwater.
Floods and floodplains are important to the life of a river and the people that depend on it. They provide
valuable ecosystem services, such as:
- Natural fertilization of floodplains.
- Water quality maintenance and toxin removal.
- Habitats for plants and animals that require natural flooding and dry seasons.
- Opportunities for sustainable agriculture and fishing.
- Replenishment of groundwater tables.
- Environmentally sustainable flood management.
Wading through the wreckage
Not all effects of a flood are beneficial. Floods are powerful forces of nature that, if mismanaged, can destroy. The images are familiar. Homes washed away, lives lost.
The negative impacts of floods are becoming worse due to large-scale projects that straighten and narrow rivers.
River courses have been straightened and constricted into artificially narrow channels to enable farming, urban development, and transport links. Floodplains that would normally store the excess flows safely have been cut off from their rivers or destroyed.
All this straightening and narrowing makes rivers flow faster over a much smaller area. Floodwaters have nowhere to go.
When the levees break
Ironically, modern flood management and control structures may increase the scale of damage because the people who live in floodplains often overestimate the level of protection provided.
Structures such as dams and dykes are designed to protect from floods of a given magnitude. They can fail when a flood exceeds their capacity. Inevitably, even though dykes are built higher and constantly reinforced, the waters will break through.