storm surge, and waves.

For river systems, a 100-year flood can be expressed as a flow rate, from which the flood elevation is derived. The resulting area of inundation is referred to as the 100-year floodplain. Estimates of the 100-year flood flow rate and other streamflow statistics for any stream in the United States are available. A 100-year storm may or may not cause a 100-year flood, because of rainfall timing