Hell and high water: New agency aims to stop catastrophic flood

Multnomah County

If the Columbia River levees break, it could threaten lives. A new special district hopes to keep that from happening.

PMG PHOTO: JAIME VALDEZ – A Union Pacific train travels over the levee that failed in 1948, leading to the Vanport Flood. Though the levee was repaired after that flood, it doesnt meet new federal safety standards set after Hurricane Katrina.

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PORTLAND, Ore. (Portland Tribune) — Most people in urbanized Multnomah County don’t know it, but they are now living under the state’s newest government — a special district created by the Oregon Legislature aimed at controlling local flooding.

The Urban Flood Safety & Water Quality District hasn’t asked the public to vote on anything yet. But, if things go according to plan, in 2025 the district will ask residents to elect the majority of a new board of directors and approve funds to help upgrade the 27-mile levee and 12 pump station system that keeps the Columbia River and Columbia Slough in their banks.

The 13,000 acres protected by the system — which stretches from North Portland to the Sandy River — is vital to the local, regional, state and national economies. It includes Portland International Airport, the Oregon Air National Guard base, Portland’s back up groundwater wells, and the Portland-Troutdale Airport, along with industrial parks, distribution warehouses, the Portland Expo Center, Portland International Raceway, critical transportation infrastructure and thousands of homes.

But the levees and pump stations are aging and, in some locations, substandard. The U.S. Army Corps of Engineers has approved upgrades to meet current Federal Emergency Management Agency standards. They will cost an estimated $130 million. The plan is currently awaiting congressional authorization.

Bob Sallinger, director of the conservation for the Audubon Society of Portland, said the plan does not meet all of the goals of the new district, which includes improving water quality, restoring habitat, and increasing equity.

“It’s pretty old school,” Sallinger said.

But Sallinger is nevertheless convinced the district’s leaders and staff are committed to all of the goals and will make progress on them in coming years. He also believes it will explore green alternatives that the plan rejected, like allowing parts of the floodplain to safely reflood, reducing the need for more hard infrastructure.

“I’m very excited about the district’s possibilities,” said Sallinger, who helped write the legislation and serves on the district’s interim board of directors.

The federal government likely will pay for two-thirds of the cost. But the four existing drainage districts along the river that currently operate and maintain the system don’t have the ability to raise the match. That includes the Multnomah County Drainage District, which does the staffing and physical work on behalf of all of them and the new district.

That is one reason why the Legislature agreed to create a replacement district that includes the much larger area within the urban growth boundary set by Metro, the elected regional government, in the county.

Another is that the system benefits the entire area within the growth boundary, and so should share the costs.

PMG PHOTOS: JAIME VALDEZ – The Portland Metro Levee System include 12 pump stations that primarily move water in the Columbia Slough from east to west through the inland levees to the Columbia River. One large station is located at the Multnomah County Drainage District headquarters and shop. Picture one shows water in the slough entering the station from the east where it is screened for debris. Picture two shows the tops of some of the five pumps that can move 30,000 gallons of water a minute when all are operating. Picture three shows some of the large pipes at the bottom of the pumps that run through the levee to the west. Picture four show where the water enters another portion of the slough on its way to the river.

Complex system needs upgrades

There is no doubt that condition of the existing system poses a threat. An earthen railroad embankment that serves of part of the system breached when the river and slough rose in 1948, flooding the city of Vanport and killing 15 people in what is now North Portland. It was rebuilt but never engineered as a flood control levee. Other sections of the levees also need to be raised and strengthened, too.

“The Portland Metro Levee System is a first line of defense for tens of thousands of people, vital public infrastructure, and thousands of acres of parks and natural spaces, including habitat for protected animal species,” U.S. Rep. Earl Blumenauer, whose 3rd Congressional District includes the system, said when the plan was announced Sept. 7. “Ensuring the resiliency of this system is one of many steps we must take to mitigate the effects of climate change and future river conditions.”

But the levees are not the only problem. The slough collects and retains stormwater from north and northeast Portland that flowed into the river before they were built. That water must be pumped in large pipes through the levees into the river to prevent flooding. And many of the pump stations needed to be upgraded.

The risks were underscored in mid-November when Fairview Lake at the headwater of the slough overflowed and flooded nearby properties because homeless campers had prevented work crews from reaching the pump station there to lower it. The situation was resolved within a few days.

PMG PHOTO: JAIME VALDEZ – Multnomah County Drainage District Public Affairs and Community Relations Specialist Aster Moulton explains how the Columbia Slough is managed at the agency’s headquarters.

The most recent study of the dangers of the existing system was conducted by the Army Corps of Engineers and the U.S. Geological Survey in March 2019. It found the river could rise to 37 feet — more than three times its average 13.3 feet height — during the kind of winter snow and rain events predicted to occur more frequently because of climate change.

The starkest finding was that a levee failure near Portland International Airport would cause an estimated $2.2 billion in damages, resulting in the loss of more than 24,000 jobs and $1.4 billion in wages in the first year — if not forever. The losses would disproportionately harm people of color because a disproportionate percent of the middle-income jobs they hold are based in the Columbia flood plain.

A 500-year flood would be more devastating, and Portland already has experienced two such floods in the past 124 years, in 1894 and in 1948, plus so-called “100-year” floods in 1956, 1964 and 1996. The need for a comprehensive solution became clear in 1996. Media coverage focused on efforts led by then-Mayor Vera Katz to prevent downtown from flooding. But portions of the drainage districts flooded and the Columbia River almost overflowed the lower sections of the levee topped by Marine Drive.

PMG PHOTO: JAIME VALDEZ – Grass growing on a levee near the Portland International airport is a model stretch on how a levee should look.

Other findings from the draft study by the state geology agency include:

• Nearly half the 8,000 people living in the drainage districts are vulnerable to being displaced if nearby levees fail. Each district has its own earthen levees, creating giant “bathtubs” that could fill with water so flooding won’t spill into the other districts.

• Though residential development has been restricted since the Vanport Flood, more than $8 billion in property is now protected by the levees.

• More than 1,000 inmates at Multnomah County Inverness Jail and Columbia River Correctional Institute could be displaced if nearby levees fail.

• More than 1,000 sites in the floodplain contain hazardous materials, including 775 sites near Portland International Airport.

• Interstates 5 and 205 could be impaired if the levees failed, as would Marine Drive, which sits atop the main east-west levee.

Planning for the future

For the past century, four tiny drainage districts in the Columbia River floodplain have collected property taxes within their boundaries to operate and maintain the levee and pump station system.

Continuing to rely on drainage districts to manage the system has some drawbacks. The Oregon Constitution includes tax limitations that sharply restrict the amount that can be raised from property taxes. And because of a phenomenon known as “compression,” an increase in taxes for the drainage districts winds up lowering taxes for Multnomah County, nearby cities and other local governments.

COURTESY LEVEE READY COLUMBIA – This map shows the locations of the four existing drainage districts along the Columbia River and Columbia Slough that will be absorbed by the new Urban Flood Safety and Water Quality District.

Several of the districts do not even have much private property to tax. Much of the property in the district farthest to the west — where the railroad embankment is located — is publicly owned, including the Portland Expo Center, Portland International Raceway and the Heron Lakes Golf Club.

A consortium of public and private interests formed Levee Ready Columbia in 2013 to find a solution. It including representatives of local, state and federal governments, plus the Port of Portland, and environmental and business groups. By 2017, it had recommended that a new utility be created that would raise money by charging the most-affected residents and businesses via monthly water bills, plus bonds paid by property owners in the entire Portland urban area and perhaps beyond.

Multnomah County and Metro both declined to assume the responsibility. So the Legislature stepped up in 2019, creating the district with a 17-member interim board. It includes representatives of 15 public entities and five community representatives appointed by Gov. Kate Brown. It is charged with organizing the new district and approving methods of funding its operation and capital projects. Former Portland City Hall and Metro manager Jim Middaugh has been hired as executive director. It has retained the ECONorthwest consulting firm to determine the best mix of funding sources in the district to pay operating and maintenance costs.

When that revenue is beginning to be collected, the interim board will call for the creation of a nine-member permanent board that will include five elected members and four members appointed by the governor, representing different constituencies. That election is currently scheduled for 2025, and is expected to include a measure to pay the local match of the improvement project. That permanent board will then dissolve the four existing drainage districts and finish assuming their responsibilities.

More information can be found at www.mcdd.org.

What’s in the plan?

The Commander of the U.S. Army Corps of Engineers has approved a plan to upgrade the Portland Metro Levee System. It includes 21 major projects intended to:

1. Address points of weakness that could result in levee breaches or overtopping, like widening and fixing the slope along the eastern side of the Peninsula Drainage Canal located just to the west of the Portland International Airport, the Columbia River Correctional Institution, and Dignity Village, and extending and elevating an incomplete floodwall under the Interstate 5 bridge.

2. Reduce the risk of internal flooding by adding pumping capacity and creating redundant power supplies at seven of the 12 pump stations within the system. This includes replacing the sole pump station on far eastern side of the levee system near the Troutdale Airport and the Troutdale Reynolds Industrial Park, which is now home to large Amazon and FedEx distribution centers.

3. Eliminate longstanding risk on the western side of the system by building a levee next to the railroad embankment that breached in 1948, leading to the destruction of the city of Vanport and displacement of more than 18,500 people. Because the railroad companies that own the embankment are not cooperating with the project, the Corps ultimately developed a proposal to build a real levee adjacent on the inside of the embankment.

The complete and final Portland Metro Levee System Integrated Feasibility Report & Environmental Assessment will be published by the Corps later this year. A link to an almost-final draft can be found in the online version of this story.

The complete and final Portland Metro Levee System Integrated Feasibility Report & Environmental Assessment will be published by the Corps later this year. A draft can be found here.

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