Quakes threaten Oregon dams as lack of funding stalls improvements

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A Cascadia Subduction Zone earthquake could occur at any time in the Pacific Northwest and some dams are not prepared

NEWPORT, Ore. (KOIN) — In the Pacific Northwest, many communities are preparing for a massive Cascadia Subduction Zone earthquake. But in Newport on the Oregon coast, a much smaller tremor could cause major destruction to the city.

A magnitude 3.0 earthquake would be enough to collapse two dams in Newport, sending a wall of water toward 20 homes, taking out Highway 101, and leaving the entire city without drinking water, the city’s mayor said. 

“This is our biggest problem in Newport right now,” Newport Mayor Dean Sawyer said. “It’s so immense.” 

According to the National Inventory of Dams, which is maintained by the Army Corps of Engineers, Oregon has 158 high-hazard potential dams, meaning if these dams fail, they’re expected to cause loss of life. The high-hazard potential could be caused by a number of things and is not solely attributed to the results of an earthquake. 

About 20 houses sit below the Big Creek Reservoirs in Newport and would be at risk of flooding if the dams failed. Photo taken Sept. 20, 2021. (KOIN)

In Newport, the Upper and Lower Big Creek Dams are experiencing an additional problem: seepage. The earthen dams, built in the late 1950s and early 1960s, are so old that water is starting to creep through them. 

The mayor says at some point, the pressure from the seepage will cause a dam to fail. 

“If there’s 20 houses down here that are in the flood zone, they will have a 30-second notice to get out, and there’s no way they could do anything,” Sawyer said. 

The City of Newport has a plan to solve the problem. It wants to construct a new roller-compacted concrete dam at a narrow point in the canyon. The problem is, the city doesn’t know how it will cover the cost of the estimated $80 million project. 

Photo taken Sept. 20, 2021 shows the site where a new dam would be constructed for the Big Creek Reservoirs. (KOIN)

Sawyer said Newport relies primarily on bonds for construction projects. However, since the city is currently paying off bonds for a new hospital, a new pool, and a recent bond for rebuilding schools, he doesn’t feel confident his taxpayers will vote in favor of the additional expense. 

“About 35% of our population here are seniors. There’s no way that they can afford the increase in property taxes, and even normal people couldn’t take that big of a hit,” Sawyer said. 

The mayor knows he’ll need to secure funding from state or federal lawmakers to help cover the cost of the project. He’s brought U.S. Sen. Jeff Merkley and Rep. Kurt Schrader to the dams to see the issue for themselves and he’s even traveled to Washington D.C. to speak to more politicians. 

So far, the only financial assistance he’s received is $14 million from the Oregon State Lottery Fund and that money might not be guaranteed. The state’s lottery bonds are contingent on lottery sales. If the state doesn’t have the $14 million, his city won’t get it. 

About 100 miles northeast of the Big Creek Dams, the Scoggins Dam on Hagg Lake in Gaston is also in need of improvements if it hopes to withstand a major earthquake. The Scoggins Dam is also an earthen dam and it was completed in 1975. 

Photo taken Sept. 20, 2021 shows the Scoggins Dam and Hagg Lake in Gaston. (KOIN)

The Bureau of Reclamation owns the dam and says a nearby Cascadia Subduction Zone earthquake could deform the dam or damage it, causing water to spill over the top or push through cracks.

Geologists have been raising alarms about the Cascadia Subduction Zone, which spans about 700 miles miles off the coast of the Pacific Northeast, from Northern California to British Columbia, and could produce a magnitude 9.0 earthquake, leaving destruction in its wake.

“Essentially, if you think about a pile of sand, and you shake it at the bottom, it starts to squash, and that’s the concern is that it would start to squash and then over top and fail,” described Tom VanderPlaat, the water supply project manager with Clean Water Services

Clean Water Services has been working in partnership with the Bureau of Reclamation on dam modifications. It uses about 25% of the water in Hagg Lake. The Joint Water Commission, which supplies drinking water to Beaverton, Hillsboro, the Tualatin Valley Water District and Forest Grove, uses another 25%, and 50% of the water is used by the Tualatin Valley Irrigation District

The City of Hillsboro does not have a backup drinking water supply. If the dam were to fail, the city would need to rely on the Tualatin Valley Water District and the City of Portland for water. 

“The Joint Water Commission still is a major source of our supplies. So, we really need to make sure that we fix these facilities so they can last into the future,” said Niki Iverson, general manager of the Joint Water Commission. 

The dangers an earthquake posed to the dams in Newport and the Scoggins Dam in Washington County were both discovered around the same time, in 2011. Like the City of Newport, the Bureau has spent the last decade coming up with potential solutions. 

It currently has three options. The first is to simply perform necessary repairs to the dam to ensure it can withstand a Cascadia Subduction Zone earthquake. 

The second and third options would increase the reservoir’s water storage capability. Officials say this is necessary to keep up with the growing population of Washington County and climate change. The second option would raise the dam 17 feet and the third would be to replace the dam by building a new one farther down Scoggins Creek. 

The Bureau of Reclamation is already performing an environmental assessment for the first option. Clean Water Services, the Joint Water Commission and the Tualatin Valley Irrigation District are in the process of conducting an environmental impact statement for the two options that would allow for additional water storage at the reservoir. 

Bob Pike, chief of the Bureau of Reclamation’s Dam Safety Program, compares making a decision on the dam to performing a medical procedure. 

“The primary objective is first do no harm, understand what you’re doing, and then take the right action to address those issues,” he said. 

Like the dams in Newport, funding is a major factor for the Scoggins Dam’s future. With the current agreement, the federal government would pay for 85% of the seismic improvements, leaving the local agencies to pay for the remaining 15%. They would also need to cover 100% of the cost of adding additional water supply to the reservoir. 

From left to right: Tom VanderPlaat, Bobby Nuvolini, and Niki Iverson stand in front of the Scoggins Dam in Gaston on Sept. 20, 2021. (KOIN)

Bobby Nuvolini, district manager for the Tualatin Valley Irrigation District, said at this point, whatever the price tag is for the project, it will likely be more than the district can afford. 

“We have a lot of smaller farmers. We have reasonable rates now but… we’d have to raise our rates to the point where I think a lot of small farmers would have to fold,” he said. 

VanderPlaat said they’re looking for partners to help share the cost. They’re considering incorporating hydroelectricity into a new dam design or sharing their water resource with fish and wildlife agencies. 

According to the Association of State Dam Safety Officials, Oregon increased its dam safety budget significantly between 2007 and 2018. Despite this, in 2018, it was still well below the national average. However, its budget for high-hazard potential dams was higher than the national average. 

For the Scoggins Dam and the Big Creek Dams, improvements could still be years away. The Bureau of Reclamation says construction on the Scoggins Dam could begin as early as 2025 or 2026. In Newport, it all depends on when the city can secure the necessary funding. 

With construction costs rising, mayor Sawyer fears what will happen if he doesn’t find funding for his project soon. 

Newport Mayor Dean Sawyer stands in front of the Upper Big Creek Dam on Sept. 20, 2021. (KOIN)

He knows the project could very well be completed at a time when he’s no longer mayor of the city. 

“This is my job today and I have to give it 100%,” he said. 

September is National Preparedness Month and is meant to increase awareness about preparing for disasters or emergencies. Iverson from the Joint Water Commission says every household should have enough stored drinking water to last 14 days in case of an emergency like a Cascadia Subduction Zone earthquake. She said families should take into account having enough water for pets. 

She also said families should have a plan on where they should meet if they are outside the home when disaster strikes. 

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