For at least the past 50 years, the Country has been using the 1% Annual Exceedance Probability (AEP) Flood, or 100-Year flood for floodplain management. Although it was a seemingly arbitrary choice, agencies like the U.S. Army Corp of Engineers determined that the 1% flood was an acceptable level of flood risk to design flood control facilities in the United States. This standard was limited to agencies specializing in flood control, but not applied to general development on a State and Local government level until the 1970s.
With the passage of the National Flood Insurance Act of 1968, the United States created the National Flood Insurance Program (NFIP). The NFIP was the first major attempt toward floodplain management. In exchange for property owners purchasing “affordable” flood insurance, communities participating in the NFIP are required to pass floodplain management regulations to reduce flood risks and losses within NFIP defined floodplains.
For more information on flood risks and/or floodplain management continue to visit this site or visit one of these resources:
Government Resources:
Federal Emergency Management Agency (FEMA) NFIP
FEMA Flood Smart (Under Redesign)
FEMA Map Service Center (View your Flood Map)
FEMA’s How to Read of Flood Map
USACE Flood Risk Management Program
Professional Organizations:
Association of State Floodplain Managers (ASFPM)
My Favorite Texas Links:
Texas Floodplain Management Association
Texas Water Development Board (Flood Resources)
Flood Risk on the Bend 