Instant Peril: Flash Floods (and How to Survive Them)

I’m contacting various emergency management agencies to see if I can get a solid response on the car question, but in light of the fact that so many flash floods are going on in the United States over recent weeks (with more in the forecast), I’m going to go ahead and publish this here. An updated version will make an appearance on Rosetta Stones next week. If you have any safety tips to add, let me know!


The eleven European tourists exploring Antelope Canyon on a fine summer day in 1997 probably never considered drowning in a desert slot canyon to be a possibility. They may have known that water carved those sandstone walls into fantastical curves and angles. But it wouldn’t have seemed like an ongoing process. Why would anyone be thinking of water, standing on dry sand, with shafts of sunlight spearing through from the narrow opening above? Despite it being the height of the Arizona monsoon season, it wasn’t raining.

It started with the sandy silt on the canyon floor leaping six inches into the air. Tour guide Pancho Quintana and his group heard a roar so loud it drowned out screams. The solid rock walls shook. They began running, trying to find a place to climb out. And then they were hit by a wall of water that filled the canyon to a depth of eleven feet. Bodies were thrown into the walls. People might find a grip for a few seconds before debris or other bodies hit them and tore them away, tumbling them down the canyon. Pancho was the lucky one: despite the water and rock tearing off his clothes and skin, he managed to get a foot wedged in a crevice. The rest of the people with him, his tour group and another, were swept out of the canyon and into Lake Powell. Some of their bodies have never been found.

How? How could water suddenly appear from nowhere and end almost a dozen lives in a few minutes?

People who grew up in the high deserts of Arizona were well aware of the potential for disaster. We were warned about flash floods from the time we were little. We knew that those dry washes and canyons could end up filled with water without warning. We knew that the sun could be shining and the ground bone dry where we were, while a thunderstorm dumping water a hundred miles away could be sending a sudden flood our way. We knew. That knowledge didn’t always save us.

Image shows a metal staircase set into wavy red sandstone.
After the disaster, metal staircases were placed in Antelope Canyon to help people escape if they’re caught in flash floods. There are also warning systems set up, and no one is allowed in if there are storms in the watershed. Credit: Moondigger (CC-By-SA-2.5)

Floods are the second deadliest weather hazard, and flash floods are the deadliest type of flood worldwide. In the United States, deaths by flash flood are increasing, while deaths by other hazards are decreasing. And they can happen in places you don’t expect. Desert denizens are well aware of the potential, but flash floods can happen in urban and suburban environments where more runoff is generated than the infrastructure can handle. They can happen in mountain valleys and streams, especially if rain falls on snow and causes unusually fast snow melt, or if rain falls on a recently-burned area, or where ice jams have backed up water. They can happen in areas that are perfectly flat, if a lot of water gets dumped with nowhere to go. They can happen downstream of dams that partially or completely fail. They can happen in any environment.

And they’re only going to get more frequent and more intense as global warming continues.

With the recent flash floods happening in Arizona, Utah, and Yemen, it’s time for us to discuss what to do. Flash floods are hard to prepare for and even harder to escape, considering they’re defined by the fact they happen quickly. But there are steps you can take that will minimize your chances of being caught in one, and will help you survive if you are. Continue reading “Instant Peril: Flash Floods (and How to Survive Them)”

Instant Peril: Flash Floods (and How to Survive Them)