A plan by the Central Oregon Irrigation District to convert 7.9 miles of canals into closed pipes has received approval by the USDA Natural Resources Conservation Service, the latest step by irrigation districts to modernize century-old infrastructure.
Construction on the pipeline is expected to start Oct. 1, said Shon Rae, deputy managing director for the district. The piping project is expected to be complete by April 2, 2022.
Central Oregon faces drought conditions that could leave some irrigation districts out of water before the end of the irrigation season. Irrigation districts say one of the best ways to conserve water is to replace the canals, which were built in the early 20th century, and lose large amounts of water into the porous soil.
Work on the Redmond to Smith Rock pipe will halt during the summer of 2021 so that water can move through the canal for normal delivery to patrons. By the summer of 2022, patrons will be getting pressurized water through the new pipes.
An Environmental Assessment from the conservation service determined that the project would not cause local, regional, or national impacts on the environment, according to a release issued by the service.
Taylor Northwest LLC of Bend was selected as the construction manager and general contractor for the first phase of the project. The project is expected to cost $33 million, said Rae.
COID has $24.9 million in secured funding from the federal grant. COID also had $8.5 million it was expected to receive from state lottery bonds, but this was lost after Oregon halted the sale of bonds in early July due to sharply declining lottery revenue. COID is working with legislators to have the funding reinstated, said Rae.
When complete, the piping project is expected to reduce water loss from seepage by nearly 30 cubic feet per second, or 9,392 acre-feet annually.
Another advantage, which applies to 638 COID patrons, is changing from a gravity-fed water system to pressurized water. When water is pressurized it allows patrons to instantly shut their water on or off, which helps with conservation efforts.
Water that is conserved from the project will be passed to the North Unit Irrigation District, which has been chronically short of water for its patrons in recent years. In return for the water, North Unit will release an equal volume of water into the Deschutes River from Wickiup Reservoir. North Unit has so-called storage rights at Wickiup and controls the dam that regulates how much water pours into the Deschutes.
Biologists say the release of additional water into the Deschutes River will help support threatened aquatic species, including the Oregon spotted frog, bull trout, and steelhead. Increased amounts of water, especially in the winter months, improves breeding areas for these species.