Plans for an Oft-Delayed Drinking Water Pipeline Under the Willamette Have Quietly Changed

The Portland Water Bureau’s earthquake resiliency planning for the westside ran into tunneling troubles.

The Portland Water Bureau has worked for 12 years to add a new pipeline to carry drinking water to the westside when the inevitable Cascadia earthquake disables the ancient water lines that currently supply that side of the city. The budget has ballooned. Bureau officials won’t say what it is, and a project that was supposed to be finished in 2022 will instead return to the Portland City Council in 2023 with a new price tag and a new plan.

At that time, the bureau will also tell councilors a key piece of information that hasn’t previously been reported: that the plan the City Council originally approved, to place a new pipeline deep in earthquake-impervious rock, won’t work.

Instead, the bureau wants to place it in soil, which engineers have said could liquefy in an earthquake and breach the existing pipelines.

“That’s a huge change,” says Ron Doctor, a retired researcher and professor who has immersed himself in Water Bureau documents.

Bureau officials say the need for the Willamette River Crossing Project, or WRX—to ensure the westside’s water supply in the event of a cataclysmic earthquake—is more urgent than ever.

The city’s two sources of drinking water—the Bull Run Watershed near Mount Hood and Columbia River wells near Portland International Airport—are both located east of the Willamette River. If a Cascadia subduction zone megaquake were to strike tomorrow, Water Bureau officials fear the city’s water could be unavailable to westsiders.

But laying down a seismically resilient pipeline under the Willamette that could survive a giant quake has proven far more difficult than expected.

“This has been two steps forward and one step back for a little while,” says Jodie Inman, the bureau’s chief engineer.

The Water Bureau first identified the issue of westside supply in 2000, began planning in 2010, started the contracting process in 2015, and signed a deal for a new pipeline in 2018, the last time the City Council had a full rundown on the WRX.

Inman and her colleagues hoped to present their new approach to the council this month, but they are still resolving technology and budget changes. “We don’t have a final cost yet,” she says.

In the meantime, residents in the South Waterfront neighborhood—who would benefit from the new pipeline but also be directly affected by clangorous drilling and construction work—have grown increasingly skeptical of the Water Bureau.

One of those residents, Doctor, has a Ph.D. in nuclear engineering and is used to studying complicated challenges. Doctor says that like a tunneling machine that’s veered off course, the Water Bureau keeps going even when a key assumption has changed.

“Last year, they completely changed the entire premise of the project,” he says. “They are now working on a plan the City Council has never seen.”

As the Water Bureau begins construction on its $820 million filtration plant in east county, the WRX project is poised to become its next big-ticket controversy before the Portland City Council.

Here’s the backstory:

How did this project start?

Back in 2000, Water Bureau engineers identified a vulnerability: More than 360,000 westside city residents, three major hospitals, and all downtown businesses get their water from five pipelines that cross under the Willamette riverbed, and one attached to the Ross Island Bridge.

The Ross Island Bridge is rickety and the pipelines are ancient (one, at Southeast Clay Street, dates to 1910). The five crossings under the Willamette rest in alluvial soil—basically, mud—on the river bottom. Scientists say that soil could liquefy in a big quake, causing the pipelines to fail.

That means no water for drinking, bathing, cooking, or putting out fires. “There is almost always a fire of some magnitude after an earthquake,” explains Water Bureau supervising engineer and WRX project manager Tim Collins in a video describing the project.

In 2010, bureau engineers began planning to add a new “seismically hardened” crossing.

What did the City Council approve?

In 2015, the Water Bureau told the council there was a high probability the sub-Willamette pipelines “would fail simultaneously” in a big earthquake, depriving westsiders of a reliable water supply for six months. Documents show the Water Bureau estimated the economic impact of that disruption to be “$1.5 to $2.5 billion.”

Sobered by that prospect, the council agreed to suspend competitive bidding requirements and greenlight a project with a $57 million price tag. The plan: tunnel through rock beneath the alluvial soil and place a new pipeline in that tunnel.

“The crossing will be located under the liquefiable soils that present the greatest seismic hazard,” the bureau told the council.

Former City Commissioner Amanda Fritz, who then oversaw the Water Bureau, says she was always impressed with the bureau’s technical proficiency, but her memory of WRX is hazy. “I do remember that before I left office [in 2021], there was a glitch with the project’s location,” Fritz says.

What changed?

In 2018, the bureau came back to the council with a new budget: $90 million. The plan, according to a council presentation from that year, had been refined.

The new pipeline would pass through a layer of rock called the “Troutdale Formation” about 140 to 150 feet deep. The price had increased, but the bureau told the council its preferred contractor, J.W. Fowler Co., was highly experienced and would complete the job by January 2022. The council approved the project.

But when Fowler started test drilling in 2020, it reported to the Water Bureau that it found the Troutdale Formation rock impenetrable.

“We had established what we believed was a viable technology,” Inman says, “but what we learned was, that technology would no longer work.”

The new plan? A much shallower placement for the pipeline, just 80 to 90 feet deep. That would place it toward the bottom of the alluvial soil that had so worried engineers years earlier.

Any problems with that?

After obtaining a copy of Fowler’s memo on the impossibility of the original plan, Doctor, the South Waterfront neighbor, cried foul. “They totally reversed the position that they’d held for the past six years,” he says.

Doctor couldn’t find any substantiation that putting a new pipeline in soil rather than rock would make a meaningful difference from the current pipelines—and he’s suspicious of computer modeling that says it would.

Inman acknowledges the drilling failure was a big blow. “We hoped we would go through a rock-type layer,” she says. But the bureau is confident. “Our new alignment is in shallower soils, but not the most liquefiable soils,” Inman adds.

Her colleague Collins says the biggest risk for pipelines fracturing is along riverbanks, not on the bottom, so raising the depth from 140 to 150 feet up to 80 to 90 feet doesn’t invalidate the new approach.

“We will be in rock on the edges,” Collins says. “And in the middle of the river, we will transition into a more dense, sandy material.”

Collins insists the city will build a pipeline that is seismically safe. “What we are doing is not cutting edge,” he adds, citing similar water pipelines in Victoria and Vancouver, B.C.

Are there alternatives to WRX?

Doctor and his allies say the Water Bureau should consider other ways to accomplish its goal, including either building westside water treatment capacity or contracting for processed Willamette River water from a large treatment plant in Wilsonville.

Inman says the Wilsonville plant lacks capacity to supply Portland, and putting a new pipeline above ground on the Tilikum Crossing would be too expensive. “We have continually reevaluated other options,” Inman says, adding that building a westside filtration plant would also be “prohibitively expensive.”

What happens next?

The Water Bureau hopes to update the City Council on its plan in the next three or four months. Doctor says he’ll be ready: “I think there is serious doubt that the pipeline as envisioned would meet the goal of providing water to the westside in the event of the quake.”