(PROVO)—A canal association plans to enclose an open ditch leaving Provo Canyon with a 21-mile pipeline to Salt Lake County. The Provo River Water Users Association says the 10.5-foot diameter pipe will keep drinking water supplies pure and eliminate evaporation losses. Utah County will finish off the pipeline route with a walking trail. The Provo Reservoir Canal, one of the largest along the Wasatch Front, carries 400 million gallons of water a day and serves municipalities in Utah and Salt Lake counties. Ames Construction Inc. will start laying pipe after irrigation season in October. The $150 million project will be funded by shareholders, the Central Utah Water Conservancy District, the U.S. Department of the Interior and a $60 million state loan.