Another skyline, of sorts, will rise starting this spring in western Davis and Weber counties as Rocky Mountain Power constructs a new main transmission line from the Box Elder County line to just west of the Salt Lake City International Airport.

Part of a $4.1 billion investment in transmission facilities, this will be an approximately 46-mile-long, double-circuit, 345,000-volt line. It will be placed in the existing Rocky Mountain Power right-of-way, about 70 feet west of the western-most transmission line in the corridor now.

"We will need an additional path of energy," said Dave Eskelsen, Rocky Mountain Power spokesman, explaining that new power plants in the future are not enough — the additional energy must be transported, too.

Rapid population growth spurred the new transmission line along the Wasatch Front.

Construction should begin this June and be finished about the spring of 2010.

Eskelsen said there are three transmission lines in this corridor now. Two of the existing lines are similar 345,000-volt facilities, while the third is a lower, 138,000-volt sub-transmission line.

The new line will go from the Ben Lomond substation just north of the Weber-Box Elder county line to the Terminal substation near the airport and will be 125 to 150 feet high.

Eskelsen said it's not the best-case scenario to have three major transmission lines in the same corridor, but he said the urbanized Wasatch Front demands it. Ideally, the three lines would be farther apart, lessening weather, range-fire and terrorist dangers.

The existing lines were installed in the 1960s and 1970s.

From the Ben Lomond substation to the Parrish substation in Centerville, about 30 miles, new single-pole steel structures will be erected. Where possible, they will match the size of the existing structures. From there southward to the airport substation, existing 230,000-volt lattice structures will be replaced with single-pole, 345,000-volt structures.

"We're facing a pretty serious deadline," Eskelsen said in regard to future electric power capacity. Current usage projections show Rocky Mountain Power being short of power along the Wasatch Front by 2012-14.

Essentially this means that during peak usage periods, such as hot summer afternoons when numerous air conditioners are operating, the company may not be able to supply everyone's power demands.

"We're approaching this in a holistic way," he said.

No one approach will ensure that electricity remains reasonably priced and available, he said, adding that Rocky Mountain is looking into such areas as renewable energy and conservation initiatives.

The new Wasatch Front transmission lines are part of Rocky Mountain's plan for 1,200 miles of new lines in Oregon, Idaho, Utah, Wyoming and Nevada.

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