Defect in Albeni Falls Dam spillway gate could take years to fully replace. North Idaho residents worry a way of life is at stake

Nov. 16—OLDTOWN, Idaho — A damaged spillway gate will make it a little harder for a federal dam to control the water level in Lake Pend Oreille for the foreseeable future.

The U.S. Army Corps of Engineers is erring on the side of lower lake levels to buffer against flooding from spring runoff. But that makes it harder for tourists and property owners to access the lake, a major economic resource in North Idaho.

"We would rather have lower lake elevation and not flood," said Taylor Johnson, the corps' chief of natural resources for Albeni Falls Dam. "That's been a real point of consternation for a lot of people."

Although the spillway is at risk of failure, the corps maintains there is no risk to the public.

"If we lost a gate and had an uncontrolled release of water, the downstream channel capacity could absorb that sudden inflow," Johnson said.

During an April inspection, the corps discovered the defect in one of the dam's 10 gates. The spillway helps control the lake level by overflowing excess water that can't pass through the dam's hydroelectric powerhouse, or by retaining extra water when the gates are down.

While the defective gate is repaired off-site, the dam's only spare gate was put in its place. The gate is expected to be back in service by spring.

Because the dam has only one spare, the corps has not had a chance to inspect the other gates and must presume they all have the same defect. To minimize unnecessary pressure on the gates, the corps is limiting gate movements and keeping them either fully closed or fully open.

"Every time we lift a gate, that's a risk," said Tony Fergert, the dam's operations and maintenance manager. "So we're trying not to do that any more than we have to."

Normally during spring runoff, the gates are opened incrementally to more gradually control the water level. When gates are all the way open, more water is released, which means less energy generated through the powerhouse.

The gates are usually down the rest of the year.

Lake Pend Oreille is a natural lake about 25 miles upriver from the dam, which was built in 1955 about a mile and a half from the Washington border. To get to the dam, water flows through a shallow bottleneck at the mouth of the Pend Oreille River near Dover. This natural pinch point would prevent the entire lake from draining. In fact, the river completely dried up at times before the dam was built, Johnson said.

If one of the gates broke, it would be no different from opening the gate during normal operations. Eventually, the river would dry up.

The biggest safety risk would be an accident while a gate was being adjusted, which could damage the bridge or overhead crane and could injure or kill the crane operator, Fergert said.

The plan to replace the spillway

Each gate is 40 feet across and 45 tons of steel. The gates undergo routine maintenance and cleaning, but work this spring was part of an in-depth rehabilitation project.

The inspection removed years of paint layers to the original base of Gate 3, which revealed holes and cracks in the two primary girders of the gate's upper leaf.

The defects were likely made during manufacturing and worsened over time. A contractor is repairing the cracks with fiber-reinforced polymer.

Once Gate 3 is returned to service, the next gate can be inspected for the flaw. But even if the other gates are OK, the corps plans to move forward with replacing them. The gates were only meant to last 50 years, and it has been almost 70.

The timeline for replacing them is longer than some lake residents had hoped.

An updated design, needed to meet modern standards, is expected to be approved by next fall. Then the project would go to bid.

The first replacement gate could be installed in 2027. After that, the corps estimates it will take another six months per gate.

Some residents have complained that timeline means it will take longer to replace the gates than the five years it took to build the dam.

"People are obviously frustrated, because it's going to take awhile," Johnson said. "You can't just get a gate from Amazon. You can't 3D-print a gate."

Nicole Celestine, a spokeswoman for the Army Corps of Engineers district office in Seattle, said the timeline is based on estimated industry availability. The original contractor no longer exists, and the bid requires a highly specialized steel fabricator, so it is not feasible to expect 11 gates at once.

The corps is working as hard as it can to fast-track the process, Celestine said, but taking the time to do it right could prevent another defect.

Idaho's congressional delegation sent a letter in June urging the corps to "resolve this situation as soon as safely possible."

Managing the lake

With the dam, Johnson said the corps has five missions to balance: generate hydroelectricity while managing the lake for flood risk, recreation, environmental stewardship and navigation.

After the defect was discovered, the corps slightly reduced the summer lake level out of caution.

The corps measures the water level by elevation from the other side of the lake at Hope, Idaho. The normal summer target is 2,062 to 2,062.5 feet. This year, that half-foot range was dropped 3 inches.

Ferger said the corps is evaluating whether to keep that range next year.

For lake users, inches mean a lot. Many fixed-pier docks and boat ramps can only be used when the lake reaches a certain elevation. Most access points are unusable throughout the winter.

Beginning in the fall, the corps drops the lake 11 feet gradually through the powerhouse. The 2,051-feet target was reached Tuesday.

The annual drawdown is scheduled for a variety of reasons. Most important, it makes space for spring runoff, but it also gives flexibility for winter power generation, prevents erosion and invasive weeds, and accommodates kokanee salmon spawning.

Last spring had an unusually light snowpack. But in normal years, the river has to pass the sudden melting onslaught from the Pend Oreille BaPhsin, which extends as far away as Butte.

"We have to ensure we don't make bad decisions in bringing the lake up too fast, because once we fill, it is super hard to get rid of," Johnson said. "Then we are flooding."

With the uncertainties after the defect was discovered, the corps delayed refilling the lake several weeks this year, but still reached the target level on June 19, two days later than the 10-year average.

The issue of water levels, however, was a concern for some lake users long before this year's restrictions.

Ralph Sletager, owner of Waterfront Property Management and the marina in Sandpoint, said that when the water level comes up at a slower rate, people book their vacations elsewhere.

Sletager is the founder of the Lake Pend Oreille Alliance, a group that argues the lake's water rights belong to Idaho, not the federal government.

The alliance's website points to a 1949 U.S. Senate document that contains a report by the chief of engineers that recommended operating the lake at full pool for "about six months" rather than the three months it does now.

In an FAQ document on the dam's website, the corps said that the initial report was not a final operating plan. The dam's water control manual was updated with public feedback after the first few years of the dam's operation and with subsequent acts of Congress, including the Endangered Species Act and Northwest Power Act.

State Rep. Mark Sauter, a Republican from Sandpoint who has asked the corps to speed up the process in replacing the gates, said he has initiated an economic impact study of lake levels on the region.

Lake access is not only important for recreation, he said, but also for emergency responders, to make it easier to launch rescue boats.

Sauter said he thinks there are alternative ways to operate the lake while still mitigating flood risk. He said that with modern data sources, the corps should be able to predict spring runoff while drawing the lake level up sooner.

The corps plans to hold a public meeting in the spring to provide updates on the spillway. In the meantime, the project has a website with more information, and the corps is collecting public feedback on lake restrictions.

James Hanlon's reporting for The Spokesman-Review is funded in part by Report for America and by members of the Spokane community. This story can be republished by other organizations for free under a Creative Commons license. For more information on this, please contact our newspaper's managing editor.