Oswego Lake Dam
Oswego Lake Dam is a concrete dam located in Clackamas County, Oregon, built in 1921. It carries a Significant hazard potential classification.
About Oswego Lake Dam
The primary purpose of Oswego Lake Dam is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Lake Oswego Corporation (private). It impounds the Tualatin River (offstream) near Lake Oswego.
The dam stands 34 feet tall and stretches 120 feet across, creates a reservoir covering 433 acres, has a maximum storage capacity of 7,000 acre-feet, and collects water from a drainage area of 6 square miles. Completed in 1921, the structure is over a century old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. The most recent inspection on record was 11/19/2020.
At 34 feet, this dam is taller than 80% of dams nationwide.
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Location
| State | Oregon |
| County | Clackamas |
| Nearest City | Lake Oswego |
| River/Stream | Tualatin River (offstream) |
| Coordinates | 45.41025, -122.66795 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 34 ft |
| Dam Height | 32 ft |
| Dam Length | 120 ft |
| Year Completed | 1921 (105 years old) |
Storage & Hydraulics
| NID Storage | 9,800 acre-ft |
| Max Storage | 7,000 acre-ft |
| Normal Storage | 9,800 acre-ft |
| Surface Area | 433 acres |
| Drainage Area | 6 sq mi |
| Max Discharge | 1,400 cfs |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | LAKE OSWEGO CORPORATION |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Not Rated |
| Last Inspection | 11/19/2020 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | OR00237 |
| Federal ID | OR00237 |
| More Info | State Dam Safety Program |