The Emerald Mile: The Epic Story of the Fastest Ride in History Through the Heart of the Grand Canyon (41 page)

Burgi didn’t spend much time staring at the Grand Canyon. As the Aero Commander initiated its descent, he fixed his attention instead on the emerging features of the dam. He could see the keyways in the sides of the canyon, where the east and the west ends of Glen’s wall notched deeply into the orange sandstone. Next he spotted the rectangular-shaped power plant crouched at the toe of the dam, and just downstream, a plume of water soaring into the river from the portal of the west spillway tunnel. Finally, he took in the switching yards on the west rim, just beyond the visitors’ center, and the little town of Page huddled on the opposite rim. From these details alone he could put together, in his mind’s eye, at least a part of what had been done to the concrete lining of the east spillway.

That was because, like the boatmen of the Grand Canyon, he had a thing for water.

Burgi had been obsessed with the personality of water ever since he’d first studied civil engineering at the University of Akron. He had devoted his career to studying the myriad ways in which water moved and behaved, particularly when it was coursing through a structure. And he didn’t really care whether that structure was the headgate on a beet farmer’s irrigation ditch or the jet valves on a giant hydroelectric dam, because both revealed the property of water that he found most mysterious and intriguing.

Those who have mastered the exceptionally complicated mathematics of fluid dynamics understand that the movements of water can be quantified and predicated with beautiful precision, but only up to a point. Beyond that point, a threshold known as turbulence, something unstable and nonlinear takes over, and water—along with most other fluids and gases—stubbornly refuses to yield up its secrets, even to some of the sharpest minds in the history of the human race. As the legendary quantum theorist Werner Heisenberg lay on his deathbed in 1974, he declared that when he met God, he anticipated asking two questions:

“Why relativity? And please explain turbulence.”

One version of this story includes a coda in which Heisenberg commented on what he expected to learn from God.

“I really think,” he said,
“that He may have an answer to the first question.”

Hydraulic equations remain some of the thorniest unsolved problems in physics, and for Burgi the mathematics of nonlinear systems and its related field of chaos theory lay far beyond his purview as a civil engineer. But he understood that a peculiar and insidious manifestation of turbulence was taking place inside the east spillway—and in a few minutes his job would be to climb down into that tunnel and diagnose its nuances.

I
t was already midafternoon when the Aero Commander touched down at the airport in Page, and a visibly anxious Tom Gamble scooped Burgi up in his station wagon. Time was running out, Gamble explained as they completed the six-minute drive, and when they arrived at the reservoir, Burgi began to grasp why.

From the window of the plane, it had been impossible for him to form an impression of just how full the lake actually was. He got his first clue when Gamble drove them out along the east side of the canyon to a parking lot about six hundred yards upstream of the dam, where Burgi stepped out and saw the gates.

The east spillway tunnel intake was controlled by a pair of steel radial gates, each of which weighed 174 tons and resembled the letter
T
tipped on its side. Each gate was fifty-two feet high and rotated on a trunnion supporting a set of
girders that formed the base of the
T.
The gates were operated by a set of cables connected to a drum hoist. The cables lifted the gates in a shallow arc, permitting the water from the lake to surge beneath the bottom of the gates and spill into a concrete trough. This configuration initially seemed odd, but anyone looking at the gates closely could grasp the logic behind their design. While the trunnion arms braced the gates against the pressure of the reservoir, the drum hoist enabled the dam’s operators to calibrate the precise volume of water they wanted to send into the tunnel.

Running across the top of each gate was a concrete bridge about twenty-five feet above the intake. When the gates were opened, twin streams of water (one from each gate) rushed along a sloping channel toward the mouth of the tunnel, an oval-shaped opening in the sandstone looming several yards below. The bridge thus enabled one to look down on the gates, the intake, and the surface of the lake. This view gave Burgi pause.

For the better part of the past three months, as the runoff had poured into the head of the reservoir more than 186 miles to the north, the surface of the lake had been nudging its way up the face of the spillway gates, and the water was now lapping less than three inches from the tops of the gates. This meant that Gamble’s team had only a narrow window to do what they needed to do. Having closed the gates to prevent water from flowing through the tunnel, they would attach Burgi to the end of a long steel cable, guide him into the mouth of the spillway, and lower him through five hundred vertical feet of rock to see what the water had done to the inside of the spillway. Once Burgi had assessed the damage, they’d fish him back up—ideally before the surface of the lake reached the tops of the gates.

Aside from whatever misgivings he may have harbored about being lowered into a giant drainpipe, Burgi had two other things to ponder during his brief walk out to the middle of the bridge. First, if the steel cable malfunctioned, he could well find himself stuck, with no way of climbing out or lowering himself down. Second, nearly fifty-two feet of water was now pressing against the face of those gates, and if they failed for any reason—or if the reservoir overtopped the gates before he could be extracted—the upper layer of Lake Powell would roar into the mouth of the spillway, snatch him up on its way down the tunnel, and spit him out the portal at the base of the dam, where the flip bucket would send whatever was left of him catapulting over the Colorado like a champagne cork.

Mercifully, perhaps, he wasn’t given much time to contemplate any of this.

At the center of the bridge was a white dual-axle flatbed truck equipped with an air compressor and a large winch. Here, Burgi discovered that he didn’t need his steel-toed boots after all. Gamble’s team handed him a pair of rubber irrigation boots, a set of rain gear, a plastic hard hat, and a portable, battery-operated
light. While he donned the gear, he cast a glance into the sloping channel and spotted what was attached to the truck’s winch. The odd-looking metal contraption looked like a cross between a go-kart and an elevator cage—a square platform surrounded by a set of guardrails, equipped with four small wheels, and featuring a tie-off pulley attached to the winch cable.

Extending from one corner of the guardrail, like a parasol stuck in a cocktail glass, was a pink umbrella. And across the face of the cart, which was painted bright yellow, someone had stenciled a phrase as a dare to anyone contemplating descending into the spillway tunnels in this contraption:

I Challenge U 2

After donning a nylon safety harness, Burgi jammed his notebook into his belt and started down a metal ladder to the surface of the sloping channel. He couldn’t help but notice that thin jets of water were squirting beneath the bottom of the closed gate and around the sides, forced through the cracks by the pressure of the reservoir. An awful lot of lake wanted to get through that steel plating.

When he stepped off the final rung of the ladder and onto the surface of the sloping channel, the shallow stream raced over the soles of his boots. He made a mental note about how slick the wet concrete surface appeared—one slip would send him skidding down the intake toward the mouth of the spillway, which loomed downstream like the entrance to a mine shaft. But Gamble’s team was prepared for his arrival.

Three men were already standing in the channel, each anchored to a safety line. Burgi was handed off from one man to the next in a kind of shuffling dance until he reached the cart and stepped on board.

Waiting inside were two technicians, one of whom carried a waterproof radio. His job would be to relay instructions to the operator of the cable hoist on the bridge. This would be their sole means of controlling their progress into the spillway and back out again. The other member of the team used a carabiner to clip Burgi’s safety harness to a stanchion on the side of the cart.

If this gate fails
, Burgi thought, casting a glance up at the leaking bulwarks of steel,
I’m gone.
With that, the cart began its journey into the mouth of the dragon.

T
he cart was about five feet wide, and the wheels canted outward to stabilize the vehicle while also discouraging it from climbing up the rounded sides of the spillway tunnel. As the winch paid the cable out, the cart slowly passed from the blinding sunlight of a June afternoon into the clip-edged shadow that marked the entrance to the tunnel, whose crown arced forty-one feet above. As they approached this threshold, the slope of the tunnel increased dramatically, angling from fifteen to fifty-five degrees, and the front of the cart suddenly
swung downward to become the floor—a transition that Burgi and his two companions negotiated with some awkward shuffling.

A six-hundred-foot incline now loomed between the men in the cart and the bottom of the tunnel. The fall wasn’t vertical, but when Burgi leaned over the rail and gazed down into the black maw yawning between the toes of his boots, it was steep enough to take his breath away. What thrilled and terrified him even more was his growing sense of the sheer size of the spillway. As they rolled down its throat, he was reminded of the biblical story of Jonah and the whale—but then he realized that the spillway’s diameter far exceeded the size of even the largest marine creature. The tunnel was
enormous
.

Within the first fifty feet, the oval-shaped patch of sky above winked out and the cart was cloaked in darkness, which only seemed to heighten the spillway’s immensity. But as the light disappeared, Burgi’s other senses began to take over.

The first thing he registered was the temperature drop. The coolness on his skin made him shiver. Another thing he noticed was the smell. He could detect the chalky odor of wet concrete, but even stronger was the clean smell of rain. Finally, there were the sounds—or more specifically, the absence of them. There were no mechanical noises—no churning turbines or whirring generators, no clanking of gate hoists or grinding of gears. Aside from the chatter between the radio operator and the folks up on the surface, all he could hear was the flow of running water—a lot more water than Burgi had expected.

The leakage from the spillway gates converged along the invert, the tunnel’s rounded centerline, to form a powerful stream that created a constant spray. In addition, every few feet the cart was also passing beneath a thin waterfall pouring from one of the many weep holes that had been drilled into the crown of the tunnel. These were designed to drain the moisture that seeped through the sandstone surrounding the outer lining of the tunnel, and as the distance from the top increased, so too did the intensity and speed of all this falling water. At the halfway point of their journey, three hundred feet into the spillway, the water in the centerline was whooshing between the wheels of the cart at nearly eighty miles per hour.

The umbrella wasn’t much help. The torrents pouring through the weep holes swiftly punched out several panels of fabric, so Burgi and his two companions gave up trying to huddle beneath it and concentrated on dodging the waterfalls. Some of these they were able to spot ahead of time and avoid; others caught them by surprise in the darkness. By the time they reached four hundred feet, all three men were soaked.

About eight minutes into their descent, Burgi noticed that the darkness seemed to be abating. At first, the illumination was so faint and pale that it seemed like a mirage. But as the light grew in strength and took on shape, a half oval, he realized that he was about to get his first glimpse of a peculiar
quirk in Glen’s spillway tunnels—a feature that was a by-product of a decision made many years before, and that now played a key role in the problem he was attempting to diagnose.