One of the most important natural functions of the floodplain is to store runoff during and immediately after large rain events. Sometimes there is too much storm water runoff for creek and stream channels to effectively handle. Too much water flow can breech the banks. The floodplain allows the water flow to low down and spread out. Eventually the water will dissipate back into the streams and rivers.
Slowing the water down and storing it in the floodplain helps decrease erosion and reduces flooding effects downstream. A large undisturbed area provides natural plant and animal habitat. Storm water is also filtered in these areas which improves quality of our drinking water.
Community parks and common open space in subdivisions often occupy areas of the floodplain. Floodplain land can be used for recreation during non-flood periods with minimal disturbance.
For additional information on the usefulness of floodplains, watch the Floodplains as a Community Asset Video.