Plans to bury almost a mile of pipeline in Provo Canyon will disrupt part of Provo's spring water during construction but will not have a lasting effect, according to a Central Utah Water Conservancy District engineer.
"We have placed monitoring wells so we can tell if the water level will be disturbed," said Sheldon Talbot, chief engineer with the Central Utah Water Conservancy District. "Once the tunnel is drilled and the lines are put in, it will have no impact on the springs."The conservancy district is spending $11 million to bury approximately one mile of the green pipe, located three miles up Provo Canyon above the Canyon Glen picnic area.
The stretch is located through a major landslide area and will be installed in a tunnel behind the slipping surface to prevent any further damage, Talbot said. The pipe from the tunnel will then tie into exposed pipe located behind the plane of slippage.
"There's a lot of landslide in that area," he said. "During extreme wet conditions (as in 1985) the ground has moved as much as 10 feet in a day."
Provo also welcomes the move to a tunnel, but the city has commissioned its own geological study to determine the impact the project will have in the springs area, said Merril Bingham, director of Provo Water Resources.
"Because of the critical nature of the springs to our supply, we hired an independent geologist to determine if there was a possibility of impact on the springs," he said.
The study is being done by Bruce Kaliser, a former geologist with the state Geological and Mineral Survey. He is evaluating Bureau of Reclamation data and his own data to determine if the tunnel will impact the springs.
Kaliser is currently conducting a chemical analysis of the spring water and looking at the material from drill holes.
The city contracted with Kaliser at an hourly rate to complete the study. "He's done a lot of work, but he is waiting for the completion of one more drill hole to include that data in his report," Bingham said.
The report is expected to be finished soon, but Bingham said preliminary findings show that the project most likely will not interfere with the springs.
If Kaliser believes there is a possibility of interference, the city will work to see if something can't be done to reduce that chance, he said.
The tunnel will go through the Spring Dell Lateral. The city gets an average of 2,000 acre feet of water a year from the springs, enough water to take care of 6,000 people.
The tunnel will be 13 feet in diameter with concrete on each side. The pipe is 10 feet in diameter.
"We feel comfortable with the steps we have taken to protect the springs," Bingham said. "When we get his report, we will know more and to what extent the area may be jeopardized. Our number one priority is to protect the spring area."
The Central Utah Water Conservancy District has also provided the city with a draft agreement, which states that the district will make it up to the city in cost if the tunneling project interferes with spring production.
"They will provide from their sources enough water to make up the difference, but we look at that as a very last alternative. We are interested in doing whatever is needed to protect the streams," Bingham said.
Construction on the tunnel will begin in October and be completed a year later, Talbot said.
The district has agreed not only to pay for increased costs of pumping wells for the amount of water decreased in the springs during construction but also to plant vegetation along the pipeline area where it will be buried.