Work will continue on defective Columbia River levee system
Sixty-seven years after the city of Vanport was leveled by raging waters of the Columbia River, the failed levee that triggered the disaster is still inadequate to withstand a major flood.
But the city of Portland and other local governments continue to work on the problem, launching a second phase of cooperative work under the auspices of an Oregon Solutions project.
The Portland City Council agreed Wednesday to participate in the second phase, which entails a year to a year and a half of studies and evaluating alternatives to build a safe levee system to thwart a catastrophic flood.
During the initial phase of work, engineers found four defects in systems managed by two local drainage districts, which could prevent certification of the levee system by the U.S. Army Corps of Engineers and Federal Emergency Management Agency, more commonly known as FEMA.
The main problem: the same levee that failed in 1948, a railroad embankment doing double-duty as a flood-control barrier, appears to include an old wooden railroad trestle that was covered in dirt. That doesnt meet current safety standards for a flood-control levee.
Its not a problem until its a problem, said Steve Greenwood, the Oregon Solutions project manager, at Wednesdays Portland City Council meeting.
The U.S. Army Corps of Engineers has reinforced the embankment over the years since the Vanport Flood of 1948, but the embankment wont pass muster as a levee under tighter standards enacted since Hurricane Katrina flooded New Orleans a decade ago. The Army Corps is requiring recertification of the Columbia River levee system in light of the new tighter standards. But Burlington Northern Santa Fe and Union Pacific railroads say its against their national policies to sign the required operation and maintenance agreements so their railroad embankment could be improved to receive federal certification as a levee.
The railroad companies also declined to allow engineers to fully analyze the embankment during the first phase of the Oregon Solutions project .
The good news, Greenwood said, is that the problems with the levee system are substantially less than we feared when we began this project.
But Oregon Solutions, which pools numerous local governments and other interested parties to tackle complex problems, still needs to devise a plan to replace the inadequate levee and fix other defects uncovered in the first phase of the project during the past year and a half.
In addition to the inadequate railroad embankment/levee, engineers found two low spots near the Interstate 5 interchange at North Marine Drive, a low spot on a levee on Port of Portland property near Portland International Airport, and an unstable smaller cross levee.
Under the second phase, engineers will expand their review of flood-control levees to include those managed by three additional drainage districts along the Columbia River, which are generally to the east and on Sauvie Island.
Portland and other local governments will continue to share the costs of the work, which likely will total several million dollars.
Portland International Airport is the most valuable asset protected by the levee system. However, the series of levees, including land underneath Northeast Marine Drive, also protect perhaps the largest industrial area in Oregon, said Jackie Dingfelder, policy director for Mayor Charlie Hales.
In all, theres $3.8 billion of homes, commercial property and other assets protected by the Columbia River levee system, Greenwood said.
If the Columbia River levee system fails to get that renewed federal certification, it would drive up costs of flood insurance for those properties. It also could prevent development of some of the land protected by the levees and reduce property values, Greenwood said.
Fortunately for the affected parties, the Army Corps and FEMA are participating in the Oregon Solutions project.