Foster Lake goes down as Corps of Engineers gets set to diagnose, treat problems with dam’s gates

Scott Swanson

Of The New Era

Foster Dam operators began lowering the water level in the reservoir Wednesday, July 16, to repair the spillway gates, the U.S. Army Corps of Engineers announced.

The drainage is expected to last 11 days and will take the lake level at least to winter pool, from 646.7 feet above sea level on Monday to 613 feet. It will virtually eliminate water skiing on the lake until the level is raised, due to obstructions in the water, and will close down at least two of the three boat ramps that service Foster.

The decision was prompted by an inspection in June that indicated two of the dam’s four spillway gates are not working properly, Corps officials said. In a statement from the Corps, officials said that during a “routine inspection of two of the four gates,” engineers began to question whether the gates would work correctly during a moderate storm event with a full reservoir.

Another inspection on Friday indicated that there were similar problems with the third gate, according to Matt Rabe, chief of public affairs for the Corps Portland office.

Officials emphasized that the dam itself is not a danger.

“Let me be very clear here, the dam is safe and not at risk of failure,” said Don Chambers, chief of the agency’s Engineering and Construction Division and dam safety officer. “We do have some concerns about the ability to safely operate these gates, so we are taking this step to ensure we meet our primary mandate – protection of public safety.”

Rabe said that although the problem was detected in June, it took some time for officials to process the information and decide how to handle the problem. Also, he said, the timing was affected by the fact that one of the dam’s two electrical generators has been off-line, which limited ways for water to get around the dam.

“We had a generator off line and two spillway gates (functioning),” he said. “That raised the level of importance (of the timing).”

The move caught some local officials by surprise and left them scrambling to figure out how to make the best of the situation with tourist season in full swing. Foster usually attracts some 300,000 visitors between June and August, according to the Corps.

Brian Carroll, director of the Linn County Parks Department, said he met with county commissioners and Corps representatives Thursday morning to discuss the situation.

He said the Corps is concerned about the condition of bearings in the dam’s spillway gates, which control the release of water from behind the dam. He said the bearings are apparently sticking and that is increasing torque on the arms that control the gate, causing them to deform.

“They’re going to get in there and see if they can relieve pressure on the bearings,” Carroll said. “In the short term, the water is going to be down. We don’t know for how long.”

Rabe said that once the lake reaches winter pool next week, a crane will be used to raise the gates and lubricate the mechanism. He said it should take about three days to raise and lube all four gates.

Although the Corps said the South Santiam River below the dam should see “minimal impact,” with flows expected to be at about 1,400 cubic feet per second, the level on Monday morning was about 1,600, according to Jack Legg, owner of DanDee Sales sporting goods store.

“The only thing we’re hearing is that the water’s going up in the river,” he said. “The Corps told us the river level was going to be 1,400 but it’s been sitting at 1,600 for the last couple of days.

“The fishermen are upset because the river keeps going up.”

The river’s normal level at this time of the year, based on the last 34 years, is 772 cubic feet per second, he said.

“In 34 years, the highest it’s ever been at this time at this time of the year is 1,600,” Legg noted.

He said the lake level used to be dropped earlier in the year, but due to recreational demands has been kept up later into the fall.

Sweet Home City Manager Craig Martin, who grew up in Sweet Home, said he can remember waterskiing in the lake in the 1970s when the water was low enough to require skiers to dodge stumps in the lake.

“I remember being on that body of water when it was not at full pool,” he said, adding that it was “a badge of honor for the young and foolish.”

Martin who is a water enthusiast, noted Foster Lake decreases in size much more rapidly than Green Peter when the water level goes down.

“A lot of the surface area of the lake is 14 feet deep at low pool,” he said. “If Green Peter drops 15 feet, you still have a lot of water. When Foster drops 15 feet, you lose 30 or 40 percent of your surface area.”

The dam’s spillway gates are used at various times of the year, but are critical to the safe release of water during and after a storm.

Carroll said the news prompted the Parks Department to close the Sunnyside boat moorage on Wednesday evening.

“We believe it will be out of the water by tonight,” he said Thursday, “so last night we asked people to pull their boats out.”

He said the newly finished Calkins park boat ramp “will come out of water pretty quickly.

“We won’t close the gates (to Calkins),” he said. “We will continue to allow access there, but we will close ramp. As it is, we’re making signs now to let people know what’s going on.”

Carroll said the Parks Department, which operates the lakeside facilities at Foster and Green Peter reservoirs, will do all it can to meet tourists’ needs. He said county officials are looking at how they can expand parking around Whitcomb Creek and Thistle Creek boat ramps at Green Peter.

“We’ll keep open as much as we can keep open,” he said. “With hot temperatures, people still need to get to the water.

“What we’re going to have to ask from the public is patience. It’s not the best scenario for boating up there.”

Steve Leith, one of the owners of the new Edgewater RV Park and one of the developers behind a proposed marina at the southwest corner of the lake, said a couple of reservations were cancelled after word got out that the lake was being lowered.

“Generally speaking, people still understand that they can launch at Sunnyside,” he said. “It’s been a pretty minimal impact so far. In the longer term and in terms of getting the marina in, it’s unclear what impacts this might have. ”

If the marina were approved, he said, the lake’s level could affect construction scheduling.

“We’re kind of in a wait-and-see mode in that regard,” Leith said.

He said the proposed marina would be largely operational even if the lake were as low as the Corps has said it could go.

“At low pool we lose 50-some slips anyway, by design – the first row of slips parallel to the shoreline,” he said. “They would still be wet but there wouldn’t be enough clearance. It wouldn’t impact us unless it were a significantly deeper drawdown.”

Martin said the Corps’ action comes at a bad time for recreation but that federal officials didn’t have a choice.

“They are supportive of recreation but they can’t compromise the integrity of the dam,” he said.