By Matt Junge, Phil Pratley, and Samantha Dunn
The Houston office of the National Weather Center estimates that Hurricane Harvey will now result in 50" of rain falling in the Houston area. That got me thinking: What exactly does 50" of rain look like?
I started thinking about this because Houston Mayor Sylvester Turner was challenged for not ordering an evacuation of his city. No doubt evacuating the fourth-largest city in the country (2.3 million residents in Houston proper, and 6.5 million in the greater metro area) would have been an immense challenge. But the challenge was made greater by the fact that most Houston residents quite reasonably had no idea what 50" of rainfall looks like. Texans were likely to understand the magnitude and potential impact of a Category Four hurricane hitting the coastline, but it was likely hard to imagine the resulting rain in their city (which is record-breaking).
According to the National Weather Service, the moisture in 1" inch of rain equals 13" inches of snow on average. That means 50" of rain contains the same amount of moisture as 54' of snow! That is enough snow to easily bury a two-story house. If I look out my window in my neighborhood, I can say with certainty that more than 50' of snow would be catastrophic.
Harvey and other recent intense rainfall events are reminding us just how catastrophic water can be. The historical way of thinking about flood is you're not at risk unless you live on the beach or next to a river. That is far from the truth.
CoreLogic recently released a report claiming that more than 50% of properties with high or medium risk of flooding aren't in an official flood zone. So many US properties are at risk of flood but unlike other perils, it is not commonly covered by a traditional insurance policy.
Flooding also may not come from a surging ocean or a rising river (which many imagine), but from falling rain that seemingly knows no end. Past events in Houston in 2015 and 2016 (neither connected to a hurricane), in South Carolina in 2015, and in California and in and around Chicago this year show us that intense rainfall happens across the US frequently. The flood risk for most of us is much greater than we realize. And often, a flood insurance policy is more affordable than we think.
How can we help property owners realize the value of flood insurance? It's usually when a mortgage lender requires us to have coverage that we begrudgingly buy a policy. But mortgage companies don't determine flood risk. And our industry can be much more innovative in educating property owners about flood.
Category: Climate/natural disasters: Climate change, Disaster risk, Floods/storms
Location: Houston, TX, United States