ONTARIO, Ore. — It will cost between $1 million and $2 million to fix the Malheur Siphon, which carries irrigation water to thousands of acres of farmland in the northern part of the Owyhee Irrigation District system.

The 4.3-mile steel pipeline, a landmark in the valley, delivers up to 325 cubic feet of water per second from the Owyhee Reservoir.

The 78-inch diameter pipeline was built in 1935 and an about three-quarter-mile-long section of it east of the Malheur Butte is starting to fail.

OID Manager Jay Chamberlin said that if the pipeline failed in the middle of growing season, it would result in about $18 million in crop losses.

“If we lose this pipe in July, that’s the worst-case scenario,” he told OID patrons March 21 during the district’s annual meeting. “That’s why we feel the urgency to do what we’re doing.”

The district last year hired MWH Americas, a Boise engineering firm, to perform a structural analysis of the pipeline and design a fix.

MWH civil engineer Gary Clark told OID patrons that most of the pipeline is in fantastic shape and should last until about 2060.

“The pipeline is worth fixing,” he said.

The problem section is in an area with bentonite clay, which, along with spikes and dips in temperature, can cause the pipe to move as much as 9 inches up and down and several inches sideways throughout the day.

“It goes through an expansion and contraction process during the day,” Chamberlin said. “It’s quite a living structure.”

Clark said the structural supports on the pipeline are starting to fail in that section because of the constant movement. Expansion joints, where the pipe slides inside itself, can also move several inches a day and are also close to failing.

These weak points have received band-aid fixes over the years, he said.

“In my opinion, it’s very close to failing at this point,” Clark said.

OID patrons this year will pay a special assessment of $1.50 per irrigable acre, which will raise about $101,000 to help fund the engineering work.

“This is going to help us get this process started,” said OID Assistant Manager Harvey Manser.

He said the district’s board of directors will seek grants and loan opportunities to help fund the project and OID employees will do as much of the work as possible to keep the cost down.

MWH’s proposed fix will involve new legs that will be designed to move relative to the pipeline and allow movement from side to side and vertically.

“This will be a lot cheaper than … having to replace this thing,” Clark said.

Work on the project, which will occur over two to three years, will take place outside irrigation season and could begin this fall, Chamberlin said.