Tolt River - South Fork
Key Takeaway
Tolt River - South Fork is classified as high hazard in Washington. It was completed in 1962 and is 64 years old. Its primary use is water supply. 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 | 200 ft (taller than 79.3% in WA) |
| Dam Length | 980 ft |
| Dam Type | Earth |
| Max Storage | 68.4K acre-ft |
| Normal Storage | 57.5K acre-ft |
| Surface Area | 1,040 acres |
| Drainage Area | 19 sq mi |
| Max Discharge | 13,000 cfs |
| Year Completed | 1962 (64 years old) |
| NID ID | WA00177 |
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
City of Seattle
Local Government
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Tolt River - South Fork?
Tolt River - South Fork 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 Tolt River - South Fork?
Tolt River - South Fork is owned by City of Seattle (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Tolt River - South Fork built?
Tolt River - South Fork was completed in 1962, making it 64 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 Tolt River - South Fork?
Tolt River - South Fork serves the following purposes: Water Supply, Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Tolt River - South Fork?
Tolt River - South Fork has a dam height of 200 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 Tolt River - South Fork last inspected?
Tolt River - South Fork was last inspected on September 28, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.