A giant teeth-gnashing machine is boring its way 85 feet under Interstate 25, two sets of railroad tracks and Fountain Creek.
The machine is cutting a 1-mile long tunnel about 20 miles south of downtown Colorado Springs for a section of a massive pipeline project that will carry millions of gallons of water from the Pueblo Reservoir to Colorado Springs.
It is the most complicated and dangerous part of the 50-mile stretch of the Southern Delivery System project, said Brian Whitehead, Colorado Springs Utilities project manager.
If all goes as planned the tunnel should be completed in the first quarter of 2015.
"This is the last section of the pipe to be constructed and the most complex part," Whitehead said. "There are risks - it's not something anyone can do."
Construction on the biggest Utilities project in its history began in 2010. The Southern Delivery System project was envisioned as the way for the city to handle future growth, said Jay Hardison, Colorado Springs Utilities water treatment plant project manager. It took years to plan and receive the proper permits from federal, state and county officials. The plan also was reviewed and approved by the Federal Aviation Administration because the new water treatment plant and holding tank off Colorado 94 are in the flight line near Colorado Springs Airport.
The $841 million project - paid for by Utilities customers through a series of water rate increases - is scheduled to be completed in September, and is on time and under its estimated $1 billion budget, said Janet Rummel, Utilities spokeswoman for the project. Engineers will take several months to test the system and will be ready to flip the switch in 2016, Hardison said.
Light at the end
Most of the SDS pipeline follows an existing power corridor north from Pueblo. But the pipeline comes up the west side of I-25 and it needed to cross the Interstate to the east so that it could curve north and hook up to a new water treatment facility at Marksheffel Road and Highway 94.
All told there are 10 tunnels bored for the SDS pipeline, including under U.S. 50, U.S. 24 and Powers Boulevard. But nothing compares to the tunnel under I-25 and Fountain Creek, Whitehead said.
The project was designed to be 50 feet under the rock, which is 35 feet below the surface. It drives under a floodplain and not one tree was disturbed, Whitehead said.
"This is the most complex because of what we had to cross," he said.
Crews from Garney Construction dug a shaft just big enough to lower the 35-foot long sections of pipe straight down. Inside, crews built a liner of steel ribs and oak lagging. Tunneling work was completed by Michels Corporation.
Each of the 162 sections of pipe have been carefully lowered in, and onto cradles that can move along tracks. Then, crews use air bags to shift the pipe so that it can match and be connected to the other sections of pipe.
"The only section left is one leading to the water treatment plant," Whitehead said.
That section is less than one mile.
The pipeline emerges from the tunnel and heads east about two miles before curving north toward Colorado Springs Utilities' seventh water treatment plant, which is under construction and 65 percent complete.
The domed $124 million water treatment facility is nearly the size of a football field and is expected to be completed in mid-July. Initially, the plant will treat about 10 million gallons of water per day but could treat as much as 50 million gallons a day, depending on demand.
"Right now it's creating reliability and allows for future demand," Hardison said.
Once treated, the water will flow to an underground holding tank that can hold 7.5 million gallons of water ready to be pumped into the existing system.
The plant was designed for expansion with two additional treatment tanks, which would allow the plant to treat up to 150 million gallons of water per day, Hardison said. At build out, SDS is expected to double Utilities current water capacity.
That would take the Utilities capacity out to 2040, if not longer, Hardison said.
"There most likely won't be another SDS project," Rummel said. "It gets us to full build out."
Contact Monica Mendoza: 636-0187