Canals in central Oregon typically lose up to 50 percent of their water through seepage. The area’s volcanic geology accounts for the high seepage rates, as canals are typically unlined with fractured basalt bottoms and sides of highly permeable soil and rock. The Bureau of Reclamation (Reclamation) constructed 18 canal lining test sections to assess effectiveness in reducing seepage. Lining materials included combinations of geosynthetics, soil, concrete, elastomeric coatings, and sprayed-in-place foam. Each test section is 100 to 300 meters long, and covers between 1,500 and 3,000 m2 This paper summarizes the construction phase including construction materials, construction techniques, unit construction costs, and initial water savings. Construction costs ranged from US $1 l to $47 per m2 Initial ponding tests indicate that seepage rates have been reduced by one to two orders of magnitude. These 18 test sections will be monitored over the next 10 years to ascertain durability (life-cycle costs) and effectiveness (long-term seepage rates) .
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