PARLEYS CANYON — Crews are putting the finishing touches on a large construction project on I-80 designed to better handle heavy run-off in the spring and keep that water off the road.
Utah Department of Transportation officials say nearly 50,000 cars and trucks travel through Parleys Canyon every day. If Parleys Creek was not diverted into a massive culvert, drivers would run into flooding problems regularly.
Over the past three months, crews blasted bedrock in the middle of the night and dug trenches 30 feet deep to build a new culvert to carry Parleys Creek underneath the interstate. Traffic delays were minimal while crews installed the culvert.
The two-mile culvert runs from the outlet of Mountain Dell Reservoir almost to the mouth of Parleys Canyon. UDOT workers have laid about 95 percent of the pipe and are 75 percent complete with the $9.5 million job.
"(We've installed) about 9,500 feet of pipe to date," said Robert Stewart, UDOT Region 2 engineer. "We still have about 1,000 feet left."
Each section of concrete pipe is 12 feet long, 66 inches in diameter and weighs more than 21,000 pounds. One section of pipe weighs about the equivalent of five average passenger cars. More than 870 pipe sections will be linked end to end over the two-mile stretch.
"The old pipe used to be right here," Stewart said, pointing to an area near the end of the pipe. "But it's since been abandoned, and they're pumping water around right now."
The old corrugated metal pipe is 50 years old and has started to erode. The new concrete pipe, manufactured at Geneva Pipe in Orem, is designed to last a century.
"We need to be able to carry that creek safely under the roadway, and that's what this pipe was designed to do," Stewart said.
A lot of force is generated in the water as it travels two miles and descends 600 feet. The structure will have a series of dissipation chambers in it, reducing that force before the water is released into the stream, Stewart said.
“The purpose of this structure is to take that force, dissipate it so that it doesn’t erode the stream as it goes farther down the road,” he said.
The project is expected to be complete in mid-October. Crews will patch the road this fall and resurface the entire project area next spring.