After nearly a century of power generation, a small hydroelectric plant near the mouth of American Fork Canyon will be decommissioned starting this
month, Rocky Mountain Power officials announced.

The Federal Energy Regulatory Commission decided in 2004 to decommission the 1,050-kilowatt plant, located 20 miles southeast of Salt Lake City, after studies found that maintenance and repairs costs made the plant's continued operation economically unviable.

The plant, which was operated since 1913 by Rocky Mountain Power, formerly Utah Power, had served about 500 homes at one time. But it hasn't been producing power for the past few years because of operational difficulties.

"We had trouble with landslides in the '80s, rockfalls in mid-90s," said Dave Eskelsen, spokesman for Rocky Mountain. "We started a review of the federal license for the plant in 1996. After years of cooperative study, federal regulators, state agencies, the stakeholders and the utility decided to remove the plant."

Today, Rocky Mountain has a total of 1.7 million customers in six states: Oregon, Washington, Wyoming, Idaho and California including 758,000 customers in Utah.

"While American Fork was a valuable hydroelectric resource for our customers for more than a century, its relatively small size, together with today's operational challenges made it a better choice to decommission and remove the project," said Rocky Mountain President Richard Walje.

Demolition work, estimated to cost $3.8 million, will be conducted by J R Merit Inc. of Vancouver, Wash. The project is scheduled to be completed in December.

Eskelsen said removal of the plant's main structures including a 4-foot high and 30-foot wide concrete dam near Little Mill campground will begin Sept. 4.

Other structures including a 12,000-foot long steel flow-line -- which carried water from diversion structures along the north slope of the canyon and into the plant to generate electricity -- will be cut and removed in sections by helicopter. A small home and garage that housed plant operators until the early 1950s will also be removed.

The plant's hydro turbine and generator will be removed and recycled, while the powerhouse, which is on the National Register of Historic Places, will be restored and conveyed to the U.S. Forest Service for its use.

"Expect traffic delays and disruptions after Labor Day," Eskelsen warned. "There will be warning signs and flaggers to control traffic on the canyon roads as heavy equipment from the dam and facilities will be removed."

Nearly 10 percent of Rocky Mountain's power is sourced from hydroelectric plants. It has 14 major hydroelectric plants producing between 10 megawatts and 260 megawatts of power, and 30 small plants producing less than 10 megawatts. Coal-run power plants account for 65 percent of Rocky Mountain's power, while the remainder comes from natural gas, wind and geothermal power and long-term and short-term purchases.