QuickTake:

Flood maps, redrawn by Federal Emergency Management Agency officials, show the risks for property owners. Lane County residents will be able to learn about the new maps and how to appeal updates during Eugene and Creswell meetings in September. 

Federal Emergency Management Agency officials are redrawing flood maps in central Lane County that will show property owners the long-term risks they face from flooding. 

The mammoth undertaking has implications for property owners, developers and residents in the region. Properties in high-risk flood zones need to have flood insurance. Developers face additional requirements to build in high-risk flood areas.

Flooding may seem like a distant and remote possibility. But the reality is that flooding is widespread – and not necessarily rare. In high-risk flood areas, properties have an approximately 1-in-4 chance of being flooded during the span of a 30-year mortgage.

It’s not an exact science and difficult to pin down, even for areas with a designated high risk. Floods can happen with a frequency that appears to contradict the language used to describe such events.

For example, a “100-year flood” can happen more than once a century.

That phrase simply refers to a flood with a 1% or greater chance of hitting a region for a given year, said Jack Blackham, permitting and floodplain manager for the city of Eugene. 

“That was nomenclature that the government assigned to those recurrence intervals in hopes of making it easier to understand,” he said. “What it actually did was kind of make it harder to understand. That doesn’t mean that there is one event every 100 years.”

Lane County has a history of floods. They also hit more than once a century. In 1964, flooding soaked Lane County, part of a flood that stretched from northern California to Washington. In 1996, rain and melted snowpack from warm temperatures in February flooded the area.

An aerial view of the 1964 flood in Lane County along Interstate 5.
An aerial view from 1964 shows flooding in Lane County, where Interstate 5 crosses the Coast Fork of the Willamette River, about 2 miles south of Creswell. Credit: Lane County

FEMA’s work stretches ahead

The federal agency’s flood maps don’t determine the insurance rates that homeowners and other property owners will pay. However, the flood risk is one factor among several others that brokers use when setting rates.

FEMA did a countywide update in 1999 and a coastal update in 2020, an agency spokesperson said. The update takes into account new technology for mapping out flood-risk zones and assigns risk levels: high, moderate and low.

“Updating flood maps is based on a combination of available funds, congressional requirements, state prioritization, and people and property at risk to flooding,” the agency said in a statement to Lookout Eugene-Springfield. 

In April, the agency released preliminary flood maps, part of a yearslong update that started in 2010. 

Countywide, the agency estimates that there currently are about 10,600 structures within the Special Flood Hazard Area — the agency’s phrase for areas with a 1% or higher chance of flooding each year — a high risk.

After its update to the maps is finalized, the agency anticipates that the hazard area on flood maps will have about 750 fewer structures: 9,850 in all. 

The changes to revised floodplain mapping included updated high-resolution terrain data along the Mohawk and Willamette rivers downstream of Springfield.

It also takes into account updated floodplain mapping along Amazon Creek, the Coast and Middle forks of the Willamette River, Fall Creek, Row Creek and Silk Creek, the agency said.

Those net changes also include structures that potentially can be added to the hazard area. 

The preliminary flood maps for central Lane County are not yet finalized. Before that happens, the public has a chance to review maps, see the designated risk area for their properties and submit comments and appeals to the federal agency. 

Public input and awareness is key. 

From Eugene to Creswell, officials are taking steps to reach out to property owners. Meetings in both communities are planned for residents. 

Eugene sent out about 4,000 postcards to property owners. In Creswell, city officials have worked with homeowner associations to get the word out to affected property owners. 

In Creswell, including its urban growth boundary, the city is going from 200 properties in the flood hazard area to a little more than 500, city planner Curtis Thomas said.

Impacted areas include a couple of manufactured home parks, Thomas said.

“That’s kind of a concern for staff because it’s harder to reach some of those properties and let them know you might have to lift up your home by a foot,” he said.

Cities are helping facilitate community meetings with FEMA and property owners, but local officials do not determine the flood risk or play a role in determining the outcomes of appeals from property owners. FEMA works with cities for outreach, but makes the final decisions.

“We do not have an ultimate say in what those maps are,” said Blackham, the Eugene floodplain manager. “We provided them with some local data for this current study, but they are the ones that say, ‘This is the map.’”

The city also adopts FEMA’s maps into its code and incorporates that into its minimum standards for floodplain development.

Tentative timelines include a 90-day appeal period that the agency anticipates will start later this year, a FEMA agency spokesperson said. An exact date wasn’t available.  

During the appeal period, the public can submit comments and corrections for maps and provide documentation indicating that the flood hazard information shown on the preliminary products is scientifically or technically incorrect.

Letters of final determination after appeals will go out in 2026. The maps could become effective as early as the spring of 2027, under the project’s tentative timeline, but that could change.

For more information about the flood map update in Lane County, go here. 

Learn more information 

In two meetings this September — one in Eugene and another in Creswell — property owners can meet with FEMA officials, view maps and learn about the federal agency’s process.

  • The Eugene meeting will be 5 p.m. Tuesday, Sept. 9, at the Eugene Public Library, 100 W. 10th Ave.
  • The Creswell meeting will be 5 p.m. Wednesday, Sept. 10, in the Creswell Community Center, 99 S. First St.

At each event, FEMA officials will give a brief presentation of the flood study update. Community members can learn more about the update and how it impacts their property and community.

Ben Botkin covers politics and policy in Lane County. He has worked as a journalist since 2003, most recently at the Oregon Capital Chronicle, where he covered justice, health and human services and documented regional efforts to fentanyl addiction. Botkin has worked in statehouses in Idaho, Nevada, Oklahoma and, of course, Oregon. When he's not working, you'll find him road tripping across the West, hiking or surfing along the Oregon Coast.