Flood Hazards in Our Area
Flooding in Eugene
Flooding has occurred in Eugene since long before the first European settlers arrived in the area in the mid-1800s. The major floods that have occurred in Eugene since the European arrival have been in 1861, 1890, 1945, 1956, and 1964.
The 1964 flood is 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. Much larger events can occur.
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)
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.
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.
The City of Eugene provides free information regarding flood hazards for specific sites within the community and can answer many of your flood-related questions. Staff can assist with flood protection and mitigation design questions and with local flooding concerns. And we can make site visits.