12-ft. diameter, 22,600 ft. long tube to cost $65 million
Salt Lake City (AP)-In a dimly lighted tunnel deep under a mountain north of Spanish Fork Canyon, Jim McDonald nodded toward a small red dot of laser light flickering near his left shoulder.
The laser beam, projected by surveyors working more than a mile away in the tunnel, fell near the middle of an 8-by 8-inch grid etched onto a small piece of Plexiglas.
It told McDonald, project manager for the joint venture drilling the tunnel, that the huge rock-boring machine slowly eating its way beneath the mountain needed a subtle adjustment. He pushed his hand through a trickle of groundwater dripping from above and tapped the grid with his finger.
“We’re just over two miles in right now, and we’re an inch-and-a half low,” he said. “We’ll adjust after we start up again.”
Once completed, the Diamond Fork Tunnel will be used as a huge underground aqueduct. It will divert water from the nearby Diamond Fork Creek, which flows out of Strawberry Reservoir, to the lower reaches of the Spanish Fork River. From there, the water will travel to major population centers along the Wasatch Front, where it will play a vital role in the future development of the state’s economy.
Utah’s water resources will define the state’s capacity to grow its industrial base, and that includes the high-tech industry, said Richard Nelson, president and chief executive officer of the Utah Information Technology Association.
“If you look at computer-chip makers such as Micron, they will eventually use a huge amount of water in their manufacturing processes,” Nelson said. “And to continue to attract that kind of development, we must have the water available.”
A tunnel-boring machine grinding a hole through a mountain may seem light years distant from the clean rooms and sterile environment of a computer chip fabrication plant. But the machine-with its 12-foot diameter cutter head spinning at nearly 12 revolutions a minute – more closely resembles a huge satellite than a piece of excavating equipment capable of grinding rock into powder.
The machine’s operator sits in a small niche off to one side. Carefully adjusting dozens of knobs switches that govern the grip of the machine on the rock walls around it, the operator can subtly change the massive machine’s direction.
Since October, three crews with seven to eight workers each have slowly guided the boring machine through the mountain. They work around the clock, five days a week, for the drilling contractor, a joint venture formed by the giant Japanese excavating firm Obayashi and Springville, Utah’s W.W. Clyde & Co.
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Huge aqueduct. A worker walks in Diamond Fork Tunnel being drilled through a mountain beneath Spanish Fork Canyon in Utah as part of the Central Utah Water Project. Once completed it will be used as a huge underground aqueduct to divert water from nearby Diamond Fork Creek to the lower reaches of the Spanish Fork River and eventually to major population centers along the Wasatch Front. AP Photo |
I’ll drive in twice on my shift to monitor for gasses,” said Robyn Snyder, as she pulled a 16-passenger “loci” to a stop near the rear of the boring machine. At a maximum speed of 8 mph, the small electric-powered locomotives that carry workers to their jobs now take 20 minutes or more to reach their destination. “The trips inside keep getting longer and longer, though.”
On a good day, the tunnel moves forward nearly 100 yards; on a bad day, 30 feet or less, McDonald said.
Drilling of the $56 million, 12-foot diameter rock tube will be halted when the 22,600-foot mark is reached early next year. Then excavators working next year near the headwaters of the Diamond Fork Creek will sink an inlet shaft down 730 feet to linkup with the tunnel below.
It is part of the Central Utah Project, a massive $2.3 billion federal and state water project launched more than 30 years ago that even now is only about 65 percent complete. The CUP’s goal is to intercept water falling on the Uinta Basin – water otherwise destined to drain into the Colorado River – and funnel it to the major population centers and agricultural areas along the Wasatch Front. The water is part of Utah’s share of Colorado River water.
“It is water that is going to be needed in years to come to meet the demands of a growing population along the Wasatch Front,” said. H. Lee Wimmer, assistant general manager of the Central Utah Water Conservancy District.
The Diamond Fork tunnel will eventually be lined with concrete a foot thick. The entire tunnel project is scheduled for completion in September 2003. Water will flow through the aqueduct at 660 cubic feet per minute, far more than Diamond Fork Creek could handle, Wimmer said.
And for Utah fly fishers, that means the Diamond Fork Creek should eventually emerge as a top trout stream.
Historically, the Diamond Fork Creek suffers from excessively high flows in the summer months that scour the stream channels and ruin the habitat for trout. With most of the water flowing into the underground tunnel, the creek will get year-round flows that are nearly ideal for brown and cutthroat trout, Wimmer said.
The number of pounds of trout in the creek is expected to increase 67 percent to 311 percent.
“Generally, I’d say that just about everything involving the Central Utah Project hasn’t been that good of a thing for the environment,” said Nate Miller, manager of the Angler’s Inn in Salt Lake City.
He noted, though, that the original CUP plan for the Spanish Fork Canyon area was to construct another reservoir, Monks Hollow, that would have inundated hundreds of acres and ruined fish habitat along Diamond Fork Creek.
“So if we end up with a prime trout stream rather than just another reservoir, it will be hard to criticize at least that (tunnel) portion of the project,” Miller added.
For Utah farmers, however, the CUP is more of a disappointment the closer it gets to completion, said Reed Balls, vice president of commodities at the Utah Farm Bureau.
“The CUP originally was conceived as a means to deliver water for both population growth and agriculture,” Balls said. “It is frustrating, though because every time they make a change in the scope of the project, more and more water gets set aside for industrial use. And you have to worry that the ultimate crop that Utah will end up growing is asphalt.”