Gate replacement likely years away

PONDERAY — It may not be what anyone wants to hear, U.S. Army Corps of Engineers officials included, replacing Albeni Falls Dam's troubled gates is going to take time.

While a plan is in the works to "patch" Gate 3 for use as a spare by spring runoff next year, full gate replacement isn't likely to begin for three years, with the project slated for completion in 2029. 

Corps officials are working to determine how to patch Gate 3, which had been pulled off the dam for inspection when the structural defects were discovered. The patch — which involves the use of a fiber-reinforced polymer as a kind of bandage of sorts to reinforce the weakened steel — could be applied in time to have the gate ready as a spare spring runoff next year.

Once the first replacement gate is installed, estimated to be in 2027, it is estimated that a new gate would be installed every six months.

The Corps has expedited the process, pushing the project to the top of the list, Col. Kathryn Sanborn, Seattle District commander, said, telling those present that she knew the news wasn't what they wanted to hear. It isn't what Corps or Bonneville Power Administration officials want either, nor state or federal officials.

"We will do what we can (to move as quickly as possible)," Sanborn said. "We don't want this to take a long time either. There's zero benefit to the Corps in that."

However, the Corps has to balance the need to move quickly with the need to do it right and ensure the replacement gates will stand the test of time.

While frustrated the project will likely take longer than hoped, the roughly 40-50 residents attending the meeting called on both Army Corps and BPA officials to do everything they can to expedite the project, noting its critical role in the area's economy and recreation options.

Several commenters asked, once the design of replacement gates is completed, whether all of the gates could be replaced at the same time, shortening the length of time for overall repairs. The sooner the dam is back to normal operation, the less harm to the area's recreation industry and overall economy, they said.

"So we have this low level, and then what?" asked one commenter. "This will impact our economy, in theory, for another four years."

While many said they understand the limitations on how quickly it will take for the gates to be replaced, they called on the Corps and BPA to do everything possible to expedite the process. A multi-year, drawn-out process will hurt residents' ability to recreate on the Pend Oreille River and Lake Pend Oreille, as well as hurt the local economy.

Sanborn and other Corps officials said they understand the need to move quickly and know the situation has impacted the community. Regional experts have been pulled into the effort and are working on both the patch of Gate 3 and longer-term replacement gates. While some of the timeframe depends on the design identified, market conditions for steel, and capabilities of the manufacturers, Sanborn said the Corps is working as quickly as it can.

Built in 1955, Gate 3 — and "highly likely" that all of the dam's 10 gates — contain base metal defects that could cause them to fail. The gate has been out of operation since a maintenance inspection in June 2023, when it was pulled off the dam to repair cracked welds and to repaint it.

The Corps identified the need for a more in-depth look at the spillway gates during routine inspections in the 2010s. Those inspections prompted the 2023 rehabilitation project.

The defects, which Sanborn described as rolling flaws, occurred when the gates were first built in the mid-1950s. The defects weaken the steel and create the potential for catastrophic failure. Unfortunately, the defects cannot be seen until a gate is taken down and decades of paint removed.

"Essentially, when steel is one solid piece of steel, it's like the sticky side of a pad of post-it notes," Sanborn said. "It's strong. It's harder to bend. It's all working as one piece. That's the way we want this steel to work. What this defect does is it essentially delaminates the steel, so it's now operating in thin little layers, and it's not as strong."

While the existing gates will be used as a basis for the design, Corps officials said current safety codes and engineering standards must and will be taken into account. While efforts are being expedited, it's likely going to be three years before a permanent repair is in place due to the engineering, design and construction of the gate replacements.

"I don't want to promise you something I can't deliver," Sanborn said, "so we're being conservative. If we can do it faster, we will certainly try to, but I don't want to commit to something and then let you all down."

In response to a question, Sanborn said that as long as one of the 1955 gates remains in operation, there is a risk of that gate failing — and of water levels changing if that happens. The restrictions are meant to minimize the potential failure of the gates until they can be replaced. If the gates were to fail, the Corps would have little notice or warning.

"What it means if the steel were to fail, what would happen is it would fracture. The fracture would happen very quickly, without warning, at a speed that approaches the speed of sound," Sanborn said of what would happen if one of the gates were to fail.

If that were to happen, it could also impact the spillway bridge and the crane used to maneuver the gates. Also placed at risk would be any operator inside the crane.

Others asked what the impact would be if multiple gates were to fail at the same time and the area had either flooding or high runoff. 

"Do you have a plan for the community, upstream and downstream, for what that looks like and the costs associated with having a winter lake level essentially?" asked Molly McCahon of the Lakes Commission.

That scenario is what the Corps is trying to avoid, Sanborn said. While failure of a single gate would introduce about 20,000 cubic feet of water into the system downstream, the geography of the region is capable of handling 95,000 cubic feet.

However, the restricted operations put in place this summer are not a long-term solution, given the elevated risk of failure of the gates and the impact of restricted operations on the community. That concern gave the project top priority to replace all 11 gates — the 10 needed for daily operation and a spare, Sanborn said.

"That's just not the kind of things we can safely leave in place," Sanborn said of the gates. "Seventy years is a lot of wear and tear."

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