Dexter Dam
Dexter Dam is an earth dam located in Lane County, Oregon, built in 1955. It carries a High hazard potential classification.
About Dexter Dam
The primary purpose of Dexter Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Usace - Portland District (federal). It impounds the Middle Fork Willamette River near Eugene.
The dam stands 117 feet tall and stretches 2,765 feet across, creates a reservoir covering 1,025 acres, has a maximum storage capacity of 29,900 acre-feet, and collects water from a drainage area of 996 square miles. Completed in 1955, the structure is well into its service life at over 50 years old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. An emergency action plan is in place for this dam. The most recent inspection on record was 03/12/2024.
At 117 feet, this dam is taller than 98% of all dams in the United States.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Oregon dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Oregon |
| County | Lane |
| Nearest City | Eugene |
| River/Stream | Middle Fork Willamette River |
| Coordinates | 43.92119, -122.80819 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 117 ft |
| Dam Height | 65 ft |
| Dam Length | 2,765 ft |
| Year Completed | 1955 (71 years old) |
Storage & Hydraulics
| NID Storage | 29,900 acre-ft |
| Max Storage | 29,900 acre-ft |
| Normal Storage | 22,200 acre-ft |
| Surface Area | 1,025 acres |
| Drainage Area | 996 sq mi |
| Max Discharge | 270,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | USACE - Portland District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 03/12/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | OR00006 |
| Federal ID | OR00006 |
| More Info | State Dam Safety Program |