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.

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 ...

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.

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.

The 100-year distinction goes thus: Every year, there is a one in 100 chance of a waterway reaching a certain elevation. That number is the 100-year level, and it is declared by the people who ...

Once every 100 years. That's the mark of a major flood. That means homes have a one percent chance of experiencing a flood in any given year. We've had three 100-year flood events in five years.

And when the real one-in-100-year flood does come, we’re not going to be able to handle the water. That just made it click for me. By using outdated flood estimates, we might be shooting ...

If you live in a 1-percent AEP (100-year) flood zone, writes USGS, the odds of being flooded at least once over a 30-year mortgage are 26%. That's about a 1 in 4 chance.

A flood that matches those points is a 100-year flood. This map from the NSW State Emergency Service shows the boundaries of the 100-year flood extent for Windsor, in the Hawkesbury-Nepean region.

On 28 February 2022, the NSW northern rivers city of Lismore recorded something between a one-in-100,000-year flood and a one-in-500-year flood level, as the river catchment rose to 14.4m.