Houston Also Had a Disastrous 'Once-in-500-Year' Flood in 2001

Route Fifty: Tropical storm Harvey, which made landfall in Texas on Friday as a hurricane and was later downgraded, has left at least five people dead, and large parts of Houston under water. Many weather watchers, stunned at the storm’s scope, dubbed it a “once-in-500-year flood.”

It’s a dramatic phrase, but one that’s easily misunderstood. And it makes the likelihood of the kind of flooding Harvey has brought appear more uncommon than it actually is.

Read article