Isaak Dam No 4
Key Takeaway
Isaak Dam No 4 is classified as high hazard in Washington. It was completed in 1987 and is 39 years old. Its primary use is irrigation. 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 Type | Earth |
| Max Storage | 64 acre-ft |
| Normal Storage | 31 acre-ft |
| Drainage Area | 150 sq mi |
| Max Discharge | 0 cfs |
| Year Completed | 1987 (39 years old) |
| NID ID | WA00591 |
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
Dugualla Bay Company LLC
Private
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Isaak Dam No 4?
Isaak Dam No 4 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 Isaak Dam No 4?
Isaak Dam No 4 is owned by Dugualla Bay Company LLC (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Isaak Dam No 4 built?
Isaak Dam No 4 was completed in 1987, making it 39 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 Isaak Dam No 4?
Isaak Dam No 4 serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
When was Isaak Dam No 4 last inspected?
Isaak Dam No 4 was last inspected on November 10, 2023. Inspection dates indicate when a formal review occurred, not the results of that inspection.