Flood Hazards in our Area

Flooding in Eugene 
Flooding has occurred in Eugene long before the first European settlers arrived in the mid-1800s in the area. The Major floods that have occurred in Eugene since then have been in 1861, 1890, 1945, 1956, and 1964.

The 1964 flood was the largest flood event recorded in Lane County, and is the “big flood” that many longtime residents refer to when discussing local flooding. However, the 1964 flood was only a 55-year-event in our community. Differences in rainfall and watershed characteristics likely explain why Eugene overall saw less flooding than in some areas.

Flooding Trends
Eugene’s major flooding events have generally occurred in December and January as a result of heavy rainfall combined with snowmelt. Reservoirs and levees are the main flood control measures for our community. To provide flood protection in the Willamette River Basin, the U.S. Army Corps of Engineers operates several reservoirs located upstream of Eugene: 
  • Cottage Grove (built in 1942)
  • Dorena (1949)
  • Lookout Point and Dexter (1953)
  • Hills Creek (1961)
  • Fall Creek (1965)

Flood Planning
The National Flood Insurance Program (NFIP) bases its flood­plain regulations, analyses and mapping on a statistically predicted event called the base flood, also known as the “100-year-flood”. The base flood has one percent chance of occurring in any given year. Even though the magnitude of destructive flood­ing has decreased due to the construction and maintenance of reservoirs and smaller local flood control channels, our community still faces flooding risks.

Properties located outside of a designated Special Flood Hazard Area (SFHA) may be affected by localized flooding or by larger flooding events. According to the Fed­eral Emergency Management Agency, approximately 25 to 30 percent of flood claims are filed by people living outside the SFHA.

Despite the reduction in flood potential from the construction of dams and other flood control projects, flooding continues to be a risk in our community. Our community’s flood maps assume that the dams upstream are operating properly, and the maps have not been updated to reflect watershed characteristic changes caused by development since the maps were originally created.

More Recent Flooding
The most recent flooding event occurred in February 1996. Unusually heavy rains over the four-day period from February 5th to February 8th resulted in significant flooding on numerous rivers and streams throughout western Oregon. The 1996 flood was only about a 25-year event for our area. It is important to note that much larger flood events are possible and that Springfield and communities downstream of Eugene experienced heavier flooding partly due to uneven rainfall. The 1996 flood should not be used to empirically gauge the likelihood of a site being flooded.

Contact Information
The City of Eugene provides free information regarding the flood hazard for specific sites within our community and related issues at the Permit and Information Center. We can be reached by phone at 541-682-8400 or in person at 99 West 10th Avenue. We are open to the public from 9:00 am to 5:00 pm, Monday through Friday. We strive to return all calls within one business day.