Leaky Dam Casts Long Shadow on Flood-Plagued Oregon Town

“The . . . torrent came at 5:30 o’clock when most of the inhabitants were at their evening meal. All were taken so suddenly . . . that nothing could be done to save those who were caught in the rushing waters. Homes, stores and all buildings in the principal portion of the town were torn loose and driven onward.”

That was a haunting eyewitness account of a 1903 flash flood that sent the swollen waters of Willow Creek coursing through this Eastern Oregon community.

Today residents wonder if it could happen again.

Dam May Be Eroding

The 5-year-old Willow Creek Dam looms 170 feet over the town of 1,375, mostly farmers, ranchers and lumbermen. That the dam leaks has been obvious from the beginning. Recent reports that the dam also may be eroding have intensified the uneasiness on Main Street.

Experts say oxygen depletion in the nutrient-rich reservoir has left pockets of chemicals corrosive enough to dissolve the concrete dam.

Roughly one-fifth of Heppner’s population--about 250 people--died in the 1903 deluge, which is listed in the Guinness Book of World Records as the worst disaster of its kind measured by per capita loss of life.

Former Mayor Cliff Green operates the hardware store where local heroes Bruce Kelly and Leslie Matlock stole a pair of wire cutters so they could cut fences and ride cross-country to warn downstream neighbors of the encroaching floodwaters. Their historic ride saved hundreds of residents in Lexington and Ione.

A system of sirens stands ready to warn townspeople in the event of a flash flood today.

But no warning could prepare them for the worst-case scenario. A breach in the Willow Creek Dam could inundate the town with 18 million tons of water.

The dam has been a touchy subject among residents even before it was built.

Opponents said the dam was unnecessary. Supporters then and now said they had little choice.

“Basically, we built the dam to save Main Street from government regulations, not from water,” said Green, whose bright yellow lapel button read, “Best Little Dam by a Townsite.”

Heppner has a history of flash floods caused by the thunderstorms locals call “waterspouts.”

The most recent, in 1971, destroyed several homes and prompted the Federal Emergency Management Agency to designate the downtown area as a flood plain.

FEMA spokesman Chuck Steele of Seattle said statistics showed that the town faced a 1% chance of a catastrophic flood in any given year, a 26% chance of such a disaster within an average 30-year mortgage cycle and a 67% chance of a major flood within 100 years.

Heppner is one of 258 communities nationwide built in flood plains as defined by the Flood Insurance Act of 1968, Steele said.

The designation requires residents to carry flood insurance and also bans any federally backed construction loans unless measures are taken to prevent future flooding.

In Heppner, it meant that the town had to be rebuilt on higher ground or protected by a flood-control dam.

Green was one of those opposed to the dam, but he finally resigned himself to the idea. What else was the town to do?

No Other Choice

“Some people said, ‘By God, they can’t make you do something like that,’ ” Green said. “But they just didn’t understand there wasn’t any other choice.”

Townspeople were bitterly divided by the issue. But in 1981, it finally was approved by a vote of 297 to 272.

A subsequent U.S. Army Corps of Engineers feasibility study showed that the cost of the project--$34.7 million--outweighed the benefits. But Sen. Mark Hatfield (R-Ore.) pressed for the dam, citing its potential to save lives.

Finally, the corps proceeded.

The decision to build the dam was vindicated before construction was completed, Green said. In 1982, fire destroyed the Heppner Post Office, the store next door and a vacant building near the center of town. None could have been rebuilt under the FEMA restriction.

Ed Hiemstra remains one of the most outspoken opponents of the Willow Creek Dam. From his back yard, he has a clear view of the dam’s wet face.

“We can see it’s disintegrating, but they’re not telling us anything,” he said. “They were looking for a sparsely settled area so they could experiment with this new type of dam, and now we’re stuck with it.”

It was the first in the world to employ a quick and inexpensive construction technique in which concrete is built up in layers like a cake instead of molded and slabbed.

Perfecting Technique

Twenty dams have been built since the roller-compacted concrete construction (RCC) method was pioneered at Willow Creek. And engineers are still perfecting the technique.

As Ronnie M. Lemons wrote in the October, 1988, issue of Civil Engineering magazine, “Even with the technology as it exists today, RCC dams leak. . . . As yet there is no consensus on how to stop those leaks.”

When it first was filled in 1983, the Willow Creek Dam leaked nearly 3,000 gallons a minute. A $2-million grouting project in 1984 reduced the leakage by 95%.

A greater problem than leaking, however, may be the corrosion of the dam from within.

In 1984, a study by environmental engineer William Funk of the Washington State University Water Research Center predicted water quality problems at Willow Creek.

Can Destroy Concrete

With experience in other cattle and sheep-feeding areas, Funk could predict a watershed rich with the kind of nutrients that can destroy concrete. Although not opposed to the dam, he said its construction weighed heavily on his mind.

“I expected to see a real mess there,” he said.

Corps scientists were surprised to find water quality deteriorating more rapidly and dramatically than Funk had anticipated. After 4 years of study, they still are not sure what it all means.

“We’re not alarmed, but we are concerned,” said Doug Larson, a lake scientist who has spent years studying the waters behind Willow Creek Dam.

“We have all the compounds present that can deteriorate concrete. We just don’t know how intense they are. The big question is: How quickly is this happening?”

Analyzing Effects

He said the answers are at least eight months away. Consultants are studying the geochemical processes occurring in the dam and the reservoir, while others are analyzing the presence of volatile methane gases and the effect of concrete-corroding acids.

“The corps’ reputation and future is on the line,” said Cliff Green. “They can’t say, ‘You’ve got a problem and it may break--send us a postcard.’ They have to do something.”

David Sykes, publisher of the Gazette-Times newspaper, said the corps already has lost credibility among the residents of Heppner.

In an angry editorial, Sykes demanded an independent analysis of the dam’s safety.

“We need more than a dose of the corps’ publicity machine,” Sykes wrote. “We need some action, to tell the truth, and it should come from our elected representatives.

“Word is out that the Willow Creek Dam is sick. The Corps of Engineers says everything is fine. But we, the people of Heppner, need a second opinion.”