Crystal Dam: A raging river runs through it
Stepping from his truck at the base of Crystal Dam, Pat Oglesby entered a world of water.
Overhead, through the drenching mist rising toward a sapphire sky, a tongue of water exploded from the dam, tearing through a gauzy rainbow into the spilling basin below our feet.
The sight was riveting, the sound immense.
No conversation was possible, or needed.
A convergence of several events, including a winter with near-record snowpacks, a Daedalian formula determining water flows in the Black Canyon of the Gunnison, and a delicate balancing of water resources by power producers and the Bureau of Reclamation, made this leaping tapestry of water happen.
“Pretty impressive, isn’t it?” asked Ted Dunn, raising his voice over the lion’s roar. “I think you got here right at the peak flows.”
Dunn is the incredibly knowledgeable and informative project manager for the three Aspinall Unit dams on the Gunnison River: Crystal, Morrow Point and Blue Mesa dams.
He gestured to his two visitors, still mesmerized by the sight of that curtain of water crashing into the spilling basin far below.
“Let’s go inside,” he suggested, knowing we otherwise might stay for hours.
It was noticeably quieter inside the dam, although it could never be described as “quiet.”
Overall, the noise was dominated by the dam’s generating unit producing electricity at peak capacity, but in the background, always in the background, was the sense of water rushing through and over the dam.
Oglesby reached a hand overhead to a fat green tube carrying the Gunnison River through the innards of Crystal Dam.
The cool metal skin of the 10-foot penstock barely vibrated, belying the amount of water rushing a few feet overhead.
Did Jonah feel a similar rumbling while awaiting salvation from the belly of the whale?
The water spins the Yugoslavian-built generator shaft at a eye-tearing 257 rpm, speeding 32 megawatts of electricity into the westwide power grid, powering air conditioners in Raton, swimming pool pumps in Phoenix and that funny electric car your neighbor tools around town in.
“It’s clean, cheap and the ultimate in renewable energy,” said Dunn, understandably proud of the benefit accruing so many Americans.
Crystal, topped out in 1976, is the “baby” of the three Aspinall units. Blue Mesa Dam was the first, built in 1963, followed by Morrow Point in 1968.
Morrow Point is unique in two ways: it was the first thin-arch, double curvature concrete dam built in the United States, and its powerplant was the first built underground by Reclamation.
Like the other Aspinall units, Crystal, also a thin-arch, double curvature dam, serves multiple functions: power production, flood protection, storing irrigation water and providing limited recreation.
Its main role, though, is to stabilize surges in flows into the Gunnison River when the other dams are producing electricity.
Blue Mesa and Morrow Point are peak power dams, meaning they kick up their power supply during times of highest demand.
When the call comes, the intakes open and the turbines whirl, sending more water downstream.
Without Crystal Dam to moderate those flows, the Gunnison through the Black Canyon would suffer similar consequences as the Colorado River below Glen Canyon Dam, producer of up to 85 percent of the power generated by the Colorado River Storage Project.
Prior to several changes in operating regulations, when Glen Canyon cranked up the power production, flows downstream might rise 10 feet in an hour.
Unannounced releases of 16,000 cfs or more weren’t uncommon (the power plant can release 33,200 cfs), making the river dangerous for anglers and other recreationists.
Starting in 1991, different operating criteria were adopted to protect downstream resources, and today releases are regulated under a complex system based in part on water storage in lakes Powell and Mead.
But those headaches were avoided when someone thought to have Crystal Dam round off the Aspinall Unit construction.
“Somebody was thinking way ahead when they designed these dams,” said Paul Sampson, one of the small cadre of multi-skilled workers keeping Crystal Dam humming. “Somehow they foresaw the importance of having three different dams play three different roles. And this certainly is one of the more important.”
How vital is Crystal’s role? It was briefly considered to build another dam downstream of Glen Canyon just to handle the situations for which Crystal was built.
We walked farther down, like moles inside the 154,400 cubic yards of concrete plugging the Gunnison River.
Square corners and cold walls separate Spartan work areas, although you never forget that everywhere you turn, a lot of water isn’t far away.
Dunn stopped and pointed to the surrounding gray walls.
“The reservoir is behind that wall, the generator is up there and we’re under the river where are standing now,” he said, turning as he spoke.
Not a place for claustrophobia, he said.
Hearing protection was available everywhere, but there’s nothing to shut out the vibration that carries through your body.
Once back outside, Dunn gestured to the endless wall of water crashing a few feet away.
“You get accustomed to it after a while,” he said smiling. “But, no, this never gets old.”