Texas Gov. Greg Abbott calls it "one of the largest disasters America has ever faced," the New York Times reports. And the numbers back him up. According to USA Today, a National Weather Service gauge outside Houston measured 49.32 inches of rain—the most ever from a tropical storm or hurricane in the continental US. And with Tropical Storm Harvey still dumping water, things aren't likely to get better anytime soon. The levee at Columbia Lakes south of Houston breached Tuesday, and Brazoria County officials weren't mincing words in a tweet: "GET OUT NOW!!" Meanwhile, the Brazos River 30 miles outside Houston measured nearly 52 feet Tuesday and is expected to reach 59 feet by Thursday—easily a record. Officials say Addicks Dam near Houston hit its overflow level, and they're worried about Barker Dam as well, the BBC reports. Here's what else you need to know: