Long Lake
Key Takeaway
Long Lake is classified as high hazard in Washington. It was completed in 1915 and is 111 years old. Its primary use is hydroelectric. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.
Physical Details
| Dam Height | 213 ft (taller than 83.7% in WA) |
| Dam Length | 593 ft |
| Dam Type | Gravity |
| Normal Storage | 105.1K acre-ft |
| Surface Area | 5,060 acres |
| Drainage Area | 5,844 sq mi |
| Max Discharge | 269,200 cfs |
| Year Completed | 1915 (111 years old) |
| NID ID | WA00021 |
Safety Information
Loss of human life is likely if the dam fails.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
Avista Corporation
Private
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Long Lake?
Long Lake is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Long Lake?
Long Lake is owned by Avista Corporation (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Long Lake built?
Long Lake was completed in 1915, making it 111 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.
What is the primary purpose of Long Lake?
Long Lake serves the following purposes: Hydroelectric, Fish And Wildlife Pond, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Long Lake?
Long Lake has a dam height of 213 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.
When was Long Lake last inspected?
Long Lake was last inspected on August 16, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.