DIAMOND FORK CANYON — Drillers saw light at the end of the tunnel Monday when they bored through to the bottom of a 65-foot shaft at the Sixth Water pipeline about 13 miles east of U.S. 6.
The huge toothed boring machine has been cutting a 5,194-foot tunnel through the mountain for about a year on this leg of the Upper Diamond Fork Project, scheduled to deliver water from Strawberry Reservoir to the Wasatch Front by October 2004. Eventually 100,900 acre-feet of water will gush through the series of tunnels and pipelines annually in Diamond Fork Canyon bringing water to farms and towns in Utah County and the Wasatch Front. Called the Bonneville Unit, it is the final effort in the federally funded $2.3 billion Central Utah Project conceived four decades ago to distribute Utah's portion of Colorado River water.
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If Utah's drought continues, the project could be crucial to providing water for the Wasatch Front, said Lee Wimmer, Central Utah Water Conservancy District construction manager.
About 84,510 acre-feet of the 100,900 acre-feet must flow annually through the tunnels to Utah Lake to replace water from Jordanelle Reservoir contracted to Salt Lake County.
Cheers from construction workers and officials from the Central Utah Water Conservancy District added to the roar when the huge drilling machine tore through the wall of the 15-foot diameter shaft completing the Tanner Ridge Tunnel dig. A huge fan was used to clear the dust billowing up from the newly dug hole. Then 16 workmen climbed through a door in the machine to pose for photos.
Since the early 1900s, Strawberry water has rushed down Diamond Fork Creek during the irrigation season.
"This will get us out of the creek," said Randy Lingwall, project engineer for Obayashi/W.W. Clyde. "We'll be able to let the fish have the creek back."
Obayashi Corp. is in partnership with W.W. Clyde Co. of Springville in constructing the $133 million water delivery project.
Strawberry Reservoir water reaches the aqueduct through the Syar Tunnel, which dates to 1916, while the newer Strawberry Tunnel feeds the creek. Now instead of being dumped into the creek at the aqueduct, the water will flow about six miles from the aqueduct through new tunnels to the Diamond Fork Pipeline in Diamond Fork Canyon, about seven miles from U.S. 6 in Spanish Fork Canyon.
From there it will empty into the Spanish Fork River and eventually into Utah Lake.
Completion of the drilling puts construction back on schedule. Work was delayed in October 2001 when a $2.6 million drilling machine struck a pocket of hydrogen sulphide at a fault line. Although no one was injured, flooding forced contractors to abandon the drilling machine in the mountain and eventually bury it.
After that experience, engineers went back to an earlier drilling plan that routes the water through two shafts before it hooks up to a steel pipeline at the mouth of Diamond Fork Canyon. The failed plan would have sent water into a single 724-foot-deep shaft before connecting with the existing pipeline.
"This is a milestone to us," Wimmer said.
Lining the Tanner Ridge Tunnel with cast concrete will follow to finish that phase of the project. That will take a year to 18 months, he said.
"It feels good when you get one that comes in ahead of schedule," Lingwall said, referring to a new schedule established when the sulphur delayed the project. The hole was drilled through the mountain a month earlier than planned on the new schedule, Wimmer said.
That has the project back to its original October 2004 completion date.
"We had to do quite a bit more work," he said.
The Tanner Ridge Tunnel cost $29 million. A diversion structure still has to be built that will route the water into the shaft and through the completed tunnel.
"This is very good," said Paul Clyde, president of W.W. Clyde. "We always like to see the tunnel hole (come through) in the right spot."