However, when wetlands are destroyed, scientists lose an important prediction tool. Sometimes flood-control structures help. However, if people build a dam, and then build their town right behind the dam, they are putting themselves at risk. A dam does not replace a wetland because it only holds back the water rather than dissipating the water underground. Leaving wetlands intact is a reminder to live in a drier area.
Some communities restore wetlands rather than build dams to control floods.
It is less expensive and better for the environment. For additional information on flooding and floodplain management, the NWF report Higher Ground is an excellent resource. Each wetland has its own hydrology and holds water differently. Still, when water flows through a wetland it is slower than when it rushes down a stream. This will slow down a flood.