Why ‘500-Year Flood’ Is An Outdated Term, Especially After Hurricane Harvey

New York Times Reporter Nadja Popovich says the term indicates the probability for such a flood in a given year, not a flood that only happens once every 500 years.

By Alexandra HartAugust 30, 2017 3:07 pm,

Hurricane Harvey marks the second “500-year flood” Houston has seen within the past year, prompting some to say it’s time to rethink how we describe such events.

Nadja Popovich, a climate reporter for The New York Times, says characterizing natural disasters like Hurricane Harvey as 500-year floods, might be more misleading than helpful. She says the phrase suggests such events happen only once every 500 years, when really, the phrase is meant to suggest the probability of the event in any given year.

Popovich says the widely used, evocative terminology is based on historic data that may no longer be useful for describing events such as Harvey. As the climate changes, she says scientists say the odds increase for extreme flooding events.


Written by Rachel Zein.