Foster Lake level leaving boaters high and dry

Sean C. Morgan

Of The New Era

Water levels are 2 feet below the normal winter pool and work was supposed to get underway on three of the four spillway gates on Foster Dam Monday.

“Today was supposed to be the start,” Corps Spokesman Matt Rabe said Monday. Apparently, the contract had a problem with the crane to be used on the project.

The crane was scheduled to undergo repairs on Tuesday and the project rescheduled to begin on Wednesday, Rabe said. The project was scheduled to take three or four days, so it is possible that the closure of Foster Dam Road could be extended.

U.S. Army Corps of Engineers Willamette Project Manager Mark Dasso visited the Sweet Home City Council during its regular meeting on July 22 to give an update and answer questions about the lowering of Foster Lake.

Foster Dam operators began lowering the water level in the reservoir on July 15 to repair the spillway gates.

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.

The drainage was expected to last 11 days taking the lake to its winter pool, from 646.7 feet above sea level to 613 or less. On Monday morning the level was 612.4 feet.

The Corps should not take the water level any lower than that, Rabe said.

As it turned out, “three of four spillway gates have been compromised,” Dasso told the council. “They have been red-tagged and are out of service.”

The Corps had found no indication of damage to the fourth gate as of July 16, he said.

The main purpose for the gates is to pass water through the dam, Dasso said. Having two to four gates in use during flood control season is not unusual, so “having three gates damaged leaves us in a very difficult position.”

It is inadequate for flood control, he said.

The Corps has had to be careful releasing water from the lake, Dasso said. This part of the year is when the gates carry their biggest load. Three of the gates have serious problems, and opening the fourth under the stress of the full lake could damage it too.

At 613 feet, the Corps can put stop logs into place and work on the gates, Dasso said. Foster has only one set of stop logs available, so the Corps will only be able to work on one gate at a time.

The Corps is greasing the bearings in the dam’s spillway gates, which control the release of water from behind the dam. The bearings were apparently sticking, increasing torque on the arms that control the gate and causing them to deform.

The gates are at risk every time they are opened, Dasso said. Before flood control season next winter, the Corps also will want to replace the bearings and decided whether to replace or straighten the deformed members in the gates.

If they simply need straightening, the Corps can heat them up and straighten them in December, he said. Replacing them means the parts need to be fabricated.

In the short term, a crane will be used to raise the gates and lubricate the mechanism. It should take about three days to raise and lube all four gates.

“Although it doesn’t look like much, it means those gates have failed,” Dasso said. If the Corps needed to use the gates for flood control, it couldn’t do it.

The actual cost of repairs will probably be in the millions of dollars, he said.

Still, “there’s a chance we’ll be able to put some water back in,” he said, adding that that will depend on how low the water goes this week.

It is unlikely the water will be raised all the way back to full pool, but the Corps does keep recreational use of the lake in mind, he said. If and when the Corps refills the lake, it will be cognizant of the levels needed to get boat ramps back in the water.

Where the lake levels end up depends on this week’s work and what more the Corps finds as it works on the dam, he said.

The Corps is performing an additional inspection this week, one it normally does during the winter, Willamette Assistant Operations Manager Dave Bardy said.

Right now, the Corps is holding water in Green Peter, with flow rates of only 50 cubic feet per second last week, Dasso said. Flows below Foster were at 1,200 cubic feet per second two weeks ago. Drawing down Foster, flows increased to 1,500 cubic feet per second. This week, the Corps will be able to maintain flows of 1,100 cubic feet per second by passing water through Foster Dam.

To draw down the lake without opening the gates, the Corps relied on the power generation plant at Foster Dam, he said.

Dasso said the Corps is frequently asked why it doesn’t inspect its dams more often.

The cost of inspection is about $100,000, he said. Foster is inspected every five years because it has never had a problem in its 42-year history.

After the replacement, it will be inspected more regularly, he said.

Ramps at Gedney Creek and Calkins Park were both out of use by Friday, Linn County Parks and Recreation Director Brian Carroll said, and by Monday only small fishing boats could be launched at the Sunnyside Campground boat ramp.

“We’re hoping that they get some good news and they get some water back,” he said.

He cautions lake users to be cautious.

“Everything’s getting nar-rower and tighter,” and stumps present a hazard, Carroll said. “Do a reconnaissance mission before you ramp up to speed.”

At least one boat has been punctured by stumps in the last week, The New Era has learned.

Carroll also is hearing from Linn County Sheriff’s Office that swimmers and boaters need to keep an eye out for each other, he said. As the water level drops, traditional swimming holes are dry.

Lewis Creek Park is high and dry, and swimmers are moving to Sunnyside, he said. The new swimming holes are close to the boating facilities. Some people are swimming right in the entry to the boat ramp, a real danger if a boater doesn’t see the swimmer.

The low lake levels aren’t doing much so far to slow down park usage, Carroll said Friday. Sunnyside Park is full, and the day use areas are busy.

Park officials have been hearing from a lot of people headed to Green Peter for boating, he said. He suggests patience using the ramp, and walks from parking will be long. He suggests that local users try to get out during the week, facing much less difficulty. Mid-week Green Peter isn’t as busy, and it has plenty of water.

He said he hopes the Corps will at least get Gedney Creek boat ramp back on-line at Foster to relieve some of that pressure, he said. The new boat ramp at Calkins Park requires full pool to use.

With the unanticipated problems at Foster, the county is waiving its 10-day requirement for reservation changes, Carroll said. If people want to check out the lake levels a couple of days prior to camping and then cancel reservations, the county will refund their money.

Campers do not need to make a decision right now on their reservations, he said. “The public’s been understanding with us. We’re trying to too.

“It’s just an unfortunate situation. I think the Corps is doing the best they can with the conditions they’ve been dealt right now.”