On July 18, 2013, David Rankin woke in his home in Big Water, Utah, at 7 a.m., as he usually does. Coffee and vanilla creamer with his wife and two boys at breakfast, a video camera tossed in his bag. Then a kiss at the door, and into his Jeep Liberty for the 20-minute drive south to Page, Arizona, where he works for the National Park Service at Glen Canyon National Recreation Area. Just an ordinary Thursday morning.

By noon, though, an unusually strong storm was blooming 40 miles north of Big Water, at the top of a 50-mile-long sandy canyon called Wahweap. The local weather website’s radar noted that nearly 3 inches of rain had fallen in less than two hours, and it was still raining hard. By 1 p.m., Rankin was back in his Jeep, “the Desert Rat,” hurtling down the road. Today, he could chase his dearest obsession: flash floods. He’d sit and wait and watch the changing weather. “And then it’s time,” he thought, “for battle.”

A large flash flood led by a debris plug, crashes down a short stretch of Utah’s Buckskin Wash in 17 seconds and eventually dumps into the Buckskin Gulch about 10 miles downstream. Credit: David Rankin

Tracking a roiling wall of mud and debris down a desert wash might seem an odd obsession for a kid from suburban Salt Lake City, but it came naturally to Rankin. When he was 8, his family moved to Big Water — once a camp for the workers who built Glen Canyon Dam in the ’50s and now home to 475 people. It has an average July high of 106 degrees and just 6 inches of precipitation a year. Rankin was enraptured, hiking alone for hours over sagebrush-lined trails and through red-rock hoodoos and deep slot canyons. He found oyster fossils and sharks’ teeth, souvenirs of the days when southern Utah soaked underwater 93 million years ago. As a kid, he hung out with paleontologists, and even found full skulls of ancient marine reptiles. A species of long-necked, ocean-dwelling reptile is named after him — Eopolycotylus rankini. “He had a brilliant mind — a good mind for bone,” helped along by hours poring over anatomy books, says Merle Graffam, now a Bureau of Land Management ranger.

Flash-flood fiend David Rankin seeks out deluges such as the one behind him in Croton Wash in Grand Staircase-Escalante National Monument. Credit: David Rankin

When Rankin was 12, the old-timers’ stories about a different monster captured his imagination: Dry nearby washes that transformed into roaring rivers in seconds. “I just couldn’t wrap my mind around it,” says Rankin, who has a round face, sturdy build and hazel eyes. So he started hanging out at Wahweap during big rainstorms — perching high up in a stone cubbyhole and getting soaked to the skin.

It was several summers before he saw the leading wall of a flood for the first time — a small, frothy affair in 2003. His real breakthrough came when Google released its Earth application. For $40, a computer science student that Rankin found in a Yahoo chat room agreed to create a custom program that overlaid real-time weather data with Google’s navigable, incredibly detailed satellite images of the local landscape. Using it, Rankin could easily estimate which local washes were likely to go big.  

Now, Rankin says, “I have it down to a science.” And sometimes that science can be, well, dull. “It’s difficult to describe the utter boredom of waiting for these things,” he says. That’s because the best way to catch a flood isn’t to sit in the storm, as he had been doing, but to stake out a spot well before it arrives, when the rain is still dozens of miles upstream. Sometimes, after waiting four hours in 95 degree heat with nothing for company but a CamelBak and his own thoughts, Rankin begins to wonder: “Am I just hoping for the impossible?” A trail sign rattles in the wind; nothing moves. And then, finally, he hears a soft rumbling in the distance. The banks of the dry wash tremble underfoot. Just as he catches a wafting scent of fresh, wet, gritty earth, the flood rolls around the corner, gnashing and crunching at an unmistakable pitch. It’s laden with debris carved from miles of canyon and riverbed, black as solidified lava and thick as wet cement. But instead of fleeing from the deadly flow, Rankin leans in closer to film it, sometimes hopping to high ground just as the water lips over his shoes.

A September 2013 flood tossed boulders through an unnamed wash and over Lees Ferry Road in Arizona, clogging its culverts. Credit: David Rankin

Getting the word out falls to the ­National Weather Service Forecast Office in Salt Lake. But the current radar system, the closest portion of which is based in Cedar City, can’t always see what Rankin sees. Projecting from a mountain 10,000 feet above sea level, its beam is at about 25,000 feet by the time it reaches Big Water, thanks to the plunging topography, the radar’s upward angle and the planet’s slight curvature. And many storms happen below 25,000 feet.

To fill in the gaps, the National Weather Service has a network of about 400 weather spotters across Utah. Most report how much rain has fallen in their area. But Rankin drives to where he thinks there will be a flood and reports back when it arrives. He and Brian McInerney, a senior hydrologist at Salt Lake’s National Weather Service Office, text about what they’re seeing — McInerney on a computer screen and Rankin in the sky. As a result, the agency catches floods it would have otherwise missed in an area frequented by millions of tourists every year. “If he indicates it’s going to happen,” McInerney says, “we issue warnings. He’s that good.”

The agency now uses Rankin’s videos to illustrate the dangers of flash floods. Over 5,000 students have watched them. Media outlets lease them for $40 per second, and over the past few years, Rankin’s had about 20 such contracts. He considers these arrangements “back-up plans” alongside website development, sculpture and digital animation, all of which he’s enjoyed moderate success with. He’s also a landscape and space photographer, and has spent days on end with little rest, taking time-lapse pictures of the night sky. “Sometimes,” he says, “I wish I didn’t have to sleep.”

YouTube video

Despite Rankin’s recurring nightmare of being run down by a flash flood in a slot canyon, he seems unlikely to ever divert too much of his energy from his deepest obsession. And that ordinary July day in 2013 turned out to be one of the best yet: Massive floods ripped through southern Utah. He drove swiftly from one bend in Wahweap to the next, chasing the flood’s roiling front wall until it had passed Big Water and was careening toward Lake Powell. The water receded within hours, as it usually does, and by the following morning, the landscape was still again. Rankin was already impatient for the next flood.  And why not? “They’ve got tornado chasers in Kansas and Oklahoma,” says McInerney. “Well, we’ve got David.” 

Tay Wiles is the online editor of High Country News.

This article appeared in the print edition of the magazine with the headline Flood chaser.

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