Flooding
100-Year Flood Defined
"Does a 100-year flood occur once every 100-years?" is
a question that we hear frequently when people discuss
floodplains. By definition, a 100-year flood, also known as the "base
flood," is a flood that has a 1% chance
of occurring in any given year. The area susceptible to flooding
during the
base flood is called the Special Flood Hazard Area, or floodplain.
The elevation of the water for a flood event of a
given probability is determined by engineers studying rainfall
intensities, stream and river cross-sections, and topography.
| 1 Year |
10% |
4% |
2% |
1% |
| 10 Years |
65% |
34% |
18% |
10% |
| 20 Years |
88% |
56% |
33% |
18% |
| 30 Years |
96% |
71% |
45% |
26% |
| 50 Years |
99% |
87% |
64% |
39% |
Studies suggests that during the 30-year life of
a typical mortgage, a structure located within the 100-year floodplain
has a 26% chance of experiencing flooding but 4%
chance of experiencing a fire. This statistic is the
reason why flood insurance coverage is mandatory for structures
whose mortgage is backed by the federal
government. Remember, your general homeowners’ insurance
policy DOES NOT cover losses from floods.
Therefore, even if you do not live in the Special Flood Hazard
Area, you should consider purchasing flood
insurance.
For more information, visit the Federal Emergency
Management Agency’s
flood website at www.fema.gov. |