The term "100-year flood" is often misunderstood—many believe it means a flood that happens once every 100 years, but that’s not how probability works. Instead, it refers to a flood that has a ...

The Brief. A "100-year flood" means a 1% chance of that level of flooding happening each year. Houston saw three 500-year flood events within three years from 2015 to 2017, including Hurricane Harvey.

That also means a 100-year flood could occur not just twice but multiple times in a single year, or not at all over the course of 150 years. It's based on probability, not predictability, say experts.

A "100-year flood" means a 1% chance of that level of flooding happening each year. Houston saw three 500-year flood events within three years from 2015 to 2017, including Hurricane Harvey.

A "100-year flood" means a 1% chance of that level of flooding happening each year. Houston saw three 500-year flood events within three years from 2015 to 2017, including Hurricane Harvey.

Every resident of Cherokee experienced last year's flood differently. One thing they had in common was the community support.

A 500-year flood means such an event has a 1 in 500 chance, or 0.2 percent, of occurring in a year. Another concept scientists use is how frequently an event of a certain intensity is expected.

A "100-year flood" means a 1% chance of that level of flooding happening each year. Houston saw three 500-year flood events within three years from 2015 to 2017, including Hurricane Harvey.

New research reveals that sections of New Orleans' $15 billion flood control system are subsiding faster than sea levels are ...

Brunswick County’s fastest-growing town is poised to expand development rules in its most vulnerable areas — a move that ...

NOAA predicts another “above average” hurricane season with between 13 and 19 named storms. Central Florida residents should be ready for heavy rains that can destroy homes within hours, even if ...