One of Central Oregon’s most ambitious canal piping projects to date, which could ultimately conserve nearly 5 billion gallons of water per year, is moving forward in Tumalo.
The Tumalo Irrigation District and the Natural Resources Conservation Service last week released a draft of their environmental assessment for a project that would pipe nearly 2 miles of the district’s main open-air canal, along with 66.9 miles of smaller canals, which irrigation officials call laterals. The total cost is $42.6 million.
The Natural Resources Conservation Service, an agency within the U.S. Department of Agriculture, estimates that the first phase of the project could save up to 2,677 acre-feet of water, the equivalent of around 872 million gallons per irrigation season.
The district believes the larger project could save up to 4.9 billion gallons of water every year.
“We wouldn’t be doing this if we didn’t think it was really, really good for water conservation,” said Tom Makowski, assistant state conservationist for watershed resources and planning for the conservation service.
Makowski said the conservation service began planning the project last June with the Deschutes Basin Board of Control, which oversees eight irrigation districts operating in the Deschutes Basin. At the time, the board identified three irrigation districts — Tumalo, Swalley and Central Oregon — to work on canal system improvements.
“Tumalo (Irrigation District) is the one that’s in front of everybody,” said Craig Horrell, managing director for Central Oregon Irrigation District.
Like many irrigation districts in Central Oregon, Tumalo relies on decades-old canals to deliver water to its 667 patrons. The environmental assessment notes the district loses about 30 percent of the water diverted through its canals to evaporation or seepage.
The irrigation district diverts water from nearby Tumalo Creek, but the flows from the creek are not sufficient for the district’s needs under the current system, according to the assessment. Partly because of that, the district has to maintain water storage at Crescent Lake. Replacing the canals with high-density polyethylene would ensure that more of the water remains in the creek, according to Makowski.
“We can do a much better job with our irrigation,” he said.
Tumalo’s project is part of a larger effort to pipe around 35 miles of irrigation canals in the Deschutes Basin over the next two decades, according to Horrell.
Horrell added that piping projects could also allow irrigation districts to transfer water back and forth. This approach should help districts with junior water rights, which can be forced to draw down Central Oregon’s reservoirs during the heart of irrigation season, according to Horrell. These types of projects, he added, will go a long way toward ensuring that enough water remains in Central Oregon’s waterways to protect species such as the Oregon spotted frog.
The conservation service, and other project partners, will host a public meeting in Bend on May 8 to discuss the assessment. Members of the public can submit comments on the assessment until May 22. Makowski added that he expects the project to break ground around the end of the irrigation season.
— Reporter: 541-617-7818, firstname.lastname@example.org
Editor’s note: This story has been corrected. The original version incorrectly identified the stream from which the irrigation district diverts water.