O S W
Key Takeaway
O S W is classified as high hazard in Wyoming. It was completed in 1912 and is 114 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 Height | 28 ft (taller than 55% in WY) |
| Dam Length | 645 ft |
| Dam Type | Earth |
| Max Storage | 360 acre-ft |
| Normal Storage | 177 acre-ft |
| Surface Area | 23 acres |
| Drainage Area | 2 sq mi |
| Max Discharge | 900 cfs |
| Year Completed | 1912 (114 years old) |
| NID ID | WY01130 |
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
LYSITE UTILITIES ASSOCIATION-STEVE SCHROCK
Private
Nearby Dams
Frequently Asked Questions
What is the hazard classification of O S W?
O S W 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 O S W?
O S W is owned by LYSITE UTILITIES ASSOCIATION-STEVE SCHROCK (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was O S W built?
O S W was completed in 1912, making it 114 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 O S W?
O S W serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is O S W?
O S W has a dam height of 28 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 O S W last inspected?
O S W was last inspected on April 5, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.