A private engineering firm says a proposed 120-mile pipeline transporting water from Lake Powell to Washington County is economically feasible and would have minimal environmental impact.

The study by Boyle Engineering of Salt Lake City is the first step in local water managers deciding whether to go ahead with the $200 million project, said Eric Loveless, branch manager for Boyle.The pipeline is one of several big-ticket projects officials are considering to slacken the thirst of this fast-growing county into the next century.

Piping water from Lake Powell is the costliest alternative. But water managers haven't decided whether to pursue it, and if they do, how to pay for it.

"These kinds of projects take decades to plan," said Ron Thompson, general manager of the Washington County Water Conservancy District. "This is a concept."

But he added that he didn't see any "significant barriers."

Loveless said a cursory look by federal land managers indicated minimal environmental impacts if the pipeline stays within existing rights-of-way.

The pipeline and two pumping stations would transport 60,000 acre feet of water along a route that roughly follows U.S. 89 to the proposed Sand Hollow Reservoir near Hurricane.

An acre foot of water meets the average annual needs of a family of four.

Without the additional water, the district could face a shortfall of up to 100,000 acre-feet in 45 years under medium growth projections, Loveless said, although conservation and development of other water sources would reduce the shortage.