Springfield receives federal assistance to address aging 42nd Street Levee

The 42nd Street Levee, a milelong earthen embankment in northcentral Springfield, reduces the risk of flooding from the McKenzie River for 24,000 people and for properties valued at more than $4 billion.

But it is 65 years old. It was built before federal standards were created to accredit levee systems. 

“We have a levee for flood protection, but nobody’s ever looked at it to see if it meets current standards,” said Springfield Emergency Manager Ken Vogeney.

In other words: Does the levee still do what it’s supposed to? Can it hold back water from the McKenzie River in case of a flood? In an interview with Lookout Eugene-Springfield, Mayor Sean VanGordon said the issue of the levee is “the one that keeps me up at night.”  

The seven-foot-tall levee is on the west bank of the river, starting at Marcola Road and ending at the entrance to the International Paper mill. A paved path for walking and biking runs atop the levee. The flood protection area extends from the river west to Interstate 5 and from Centennial Boulevard north to the river. 

Vogeney is working with the U.S. Army Corps of Engineers on a feasibility study to determine what is needed to provide accreditation for the levee. The conversation started in 2017 when the Federal Emergency Management Agency began a project to update its floodplain maps for the McKenzie River.

When FEMA first mapped the floodplain, it used the levy as a boundary because it was recognized as a flood control structure. With the updated maps, FEMA informed the city that the levee needed to be certified as meeting current federal standards. If the levee isn’t accredited, FEMA will map the floodplain assuming the levee doesn’t exist, which could change the floodplain boundaries, Vogeney said.

That means some property owners in the area who have a federally backed mortgage will need flood insurance. Vogeney said that could be a few thousand properties. 

“So none of these folks know that they needed to worry about potentially being within a floodplain area,” he said.

The feasibility study with the Army Corps of Engineers will take about two years and will make recommendations for improvements to the levee. 

“They are our subject matter experts and design team for identifying what our issues might be with the levy and then helping us come up with a plan and ultimately implementing that plan through construction,” Vogeney said. 

A city brochure about the levee states the project’s total cost is currently estimated at $10 million. The city will share that cost with the Army Corps of Engineers under its Continuing Authorities Program.

Once levee improvements are complete, an engineer will certify that it meets federal standards and the certification will be submitted to FEMA for accreditation, the brochure states. FEMA will then need to update its floodplain maps to recognize the flood management provided by the levee. 

Adding height 

The Soil Conservation Service built the levee in 1960. At the time the levee was under the jurisdiction of Lane County. Springfield took ownership of the levee in 1983. 

Vogeney said officials haven’t made any structural improvements to the levee since it was built. The path on top of the levee, however, was a railroad spur for about 20 years, with cars hauling lumber from Wendling to the Weyerhaeuser mill. In the early 2000s, the city worked with the Oregon Department of Transportation to remove the rail line and build a multiuse path on top of the levy. 

Vogeney said the city knows the levee isn’t tall enough. 

FEMA uses a calculation called the base flood elevation to determine how high a levee needs to be. The calculation uses historical data about rainfall and stream stage to determine the base flood elevation, which is how high water might rise during a flood that has a 1% chance of happening in any year, according to the U.S. Geological Survey. 

According to the federal standards, the levee needs to have a minimum of three feet of clearance above the base flood elevation. 

The largest flood since the levee was built occurred in December 1964. Vogeney said floodwaters got within six inches of overlapping the levee during that event. 

The assessment will look at the costs of raising the whole levee or part of the structure or building a concrete wall atop the embankment. Vogeney said there will be a public engagement process that goes along with making that decision, because many people use the paved path on top of the levee as well as a gravel path near the river for recreation. 

Last month, the city closed the paved path and adjacent gravel road for a few days so engineers could take soil samples from around the levee. Crews drilled three 30-feet holes from the top of the levee and between the levee and the river. 

Those samples are being tested at a lab to determine the materials that were used to construct the levee and the strength of the soil. The results will help engineers determine if the levee is impervious, meaning it will prevent water from passing through it. Results will also help them figure out if the foundation will structurally support an addition to the levee. 

Vogeney said the engineers are also assessing the state of the levee’s existing riprap, which is an armor of large rocks placed along the levee to protect it from erosion. They need to determine if the riprap rocks are big enough and placed correctly to prevent them from being washed away. 

VanGordon said he wants the community to know that the levee is an issue and that the city is doing what it can to be proactive about addressing it.

“This has been a significant issue for us, as well as for our federal and state delegations,” he said. 

VanGordon said he’s excited to be going from knowing that the levee needs to be updated to working on understanding what is needed to improve it. 

Emergency action plan

The city hired an engineering consultant in 2023 to prepare an Emergency Action Plan for the levee, “to reduce the risk of loss of human life and injury and minimize property damage in the event of an actual or potential emergency” associated with the levee.

The plan provides procedures to identify “unusual and unlikely conditions that may endanger” the levee in time to take action.

The plan also identifies areas that would suffer the most during a levee failure. Officials used the levels of the 1964 flood to compile an aggregate map of four levee failure scenarios, Vogeney said. The map shows that areas closest to the levee could experience 1.5 feet to more than 3 feet of flooding (marked in orange and red), with areas further west getting less than 0.5 feet and up to 1.5 feet of water (marked in green and yellow). 

Much of the area closest to the levee is industrial, including the Springfield School District bus yard and the Oregon National Guard, as well as a trucking company and garden center. Residential areas are within a few blocks of the levee, however. 

“The amount of property and things that are in the way of a potential breach, there’s quite a bit there,” VanGordon said. “And I’ve always been a firm believer that, long-term challenges, we should continue to keep them front and center and then continue to work on things that are going to keep the city of Springfield and the residents and property around here as safe as possible.

“If we had a flood event and it breached, the impact to people in north Springfield is significant, and you can see that in the map,” the mayor added. 

In the meantime, the city has purchased plastic temporary flood barriers that can be attached to the concrete path on top of the levee. Each fall the city does a training exercise with the barriers, which come in three-foot sections and snap together to be watertight. 

What the National Levee Database says

Springfield worked with FEMA in 2019 to add the 42nd Street Levee to the National Levee Database. Vogeney said the city wanted to add the levee to the national inventory so that more people would know about it.

According to that database, a risk assessment of the levee found it to have a moderate level of risk based on flood hazard and frequency, the anticipated levee performance and the potential consequences.

The McKenzie River is migrating west toward the levee, making it increasingly susceptible to erosion damage, information on the database states. 

“If the levee were to fail, the flood depths are anticipated to be shallow, but the water may be swift-moving near the point of levee failure, causing structural damage and potentially being life-threatening,” according to the database. 

Vogeney said one of his biggest takeaways from the National Levy Database was learning about the McKenzie River channel migration. Due to soil erosion, the river is migrating west toward the levee at an average of 10 feet per year since its construction. 

Channel migration is the natural process by which streams move laterally over time, according to the Oregon Department of Geology and Mineral Industries. 

“As the river continues, it puts at risk undermining the levee, thus causing it to fail,” he said. “So the work that I’m doing with the Corps of Engineers is for both the levee itself and to stabilize this bank erosion so that the river doesn’t actually damage the levee.”