Harvey’s rain fell beyond Houston

The claim: “Harvey dropped more water on Houston in five days than goes over Niagara Falls in a year.” — John Kerry, special envoy on climate to President Joe Biden.

Kerry made the statement in a Jan. 31 appearance on CNN, in which he described the Biden administration’s whole-of-government approach to addressing climate change.

PolitiFact rating: False. By the time Hurricane Harvey dissipated, it had dropped around 33 trillion gallons of water primarily on Texas, Louisiana and, to a lesser extent, Tennessee and Kentucky. By comparison, about 23.8 trillion gallons flows over Niagara Falls per year.

Kerry’s comment errs in narrowing Harvey’s rainfall to Houston, and his office acknowledged the misstatement.

Discussion

It’s true that Harvey produced rainfall levels that have never been experienced in the U.S. in recorded history. According to Texas State Climatologist John Nielsen-Gammon, the amount of rainfall during a five-day period across 10,000 square miles of Texas and Louisiana exceeded the previous record set in 1899 by 62 percent.

In Harris County alone, which contains the bulk of the city of Houston, the storm dropped an average 33.7 inches of rainfall across the county’s 1,777-square-mile area.

A spokesperson for the State Department said Kerry’s remark was based on a 2017 Washington Post article reporting that Harvey had dumped 24.5 trillion gallons of water on Southeast Texas and southern Louisiana.

The article also mentions, for the sake of comparison, that 1 trillion gallons of water flows over Niagara Falls every 15 days, and Kerry’s office used that number to extrapo

late the amount of water that flows over the falls in a year.

“A trillion gallons falls over Niagara Falls every 15 days. So, in the course of 365 days, that is about 24.3 trillion gallons of water,” State Department spokesperson James Dewey said.

That back-of-the-envelope calculation is correct, and it closely lines up with official estimates. Niagara Falls State Park estimates that 757,500 gallons flows over the falls each second, which is equivalent to 65.4 billion gallons per day, or 23.8 trillion gallons per year.

In either case — be it Kerry’s estimate of 24.3 trillion gallons flowing over Niagara per year or the state park’s 23.8 trillion estimate — both figures are less than the 24.5 trillion gallons of water Harvey unleashed.

However, there’s a key detail that Kerry gets wrong.

While it might be true that Harvey dropped more water within a week than what flows over Niagara Falls in a year, not all that Harvey water fell on Houston or Harris County alone.

After PolitiFact reached out to Kerry’s office about the misstatement, a spokesperson said the issue has been brought up to staff and that Kerry would be more careful with that statistic.

“In a recent interview with Fareed Zakaria on CNN, Secretary Kerry said Hurricane Harvey ‘dropped more water on Houston in five days than goes over Niagara Falls in a year,’ ” a spokesperson said in a statement. “The statistic Secretary Kerry referenced is for water Hurricane Harvey dropped not just on Houston, but on Southeast Texas and southern Louisiana.”