Grand Lake St. Marys - West Embankment
Key Takeaway
Grand Lake St. Marys - West Embankment is classified as high hazard in Ohio. It was completed in 1841 and is 185 years old. Its primary use is recreation. 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 | 20 ft (taller than 27.7% in OH) |
| Dam Length | 9,760 ft |
| Dam Type | Earth |
| Max Storage | 156.4K acre-ft |
| Normal Storage | 62.9K acre-ft |
| Surface Area | 13,981 acres |
| Drainage Area | 106 sq mi |
| Max Discharge | 18,000 cfs |
| Year Completed | 1841 (185 years old) |
| NID ID | OH00580 |
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
ODNR, Division of Parks & Watercraft
State Government
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Low Hazard 15 ftFrequently Asked Questions
What is the hazard classification of Grand Lake St. Marys - West Embankment?
Grand Lake St. Marys - West Embankment 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 Grand Lake St. Marys - West Embankment?
Grand Lake St. Marys - West Embankment is owned by ODNR, Division of Parks & Watercraft (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Grand Lake St. Marys - West Embankment built?
Grand Lake St. Marys - West Embankment was completed in 1841, making it 185 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 Grand Lake St. Marys - West Embankment?
Grand Lake St. Marys - West Embankment serves the following purposes: Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Grand Lake St. Marys - West Embankment?
Grand Lake St. Marys - West Embankment has a dam height of 20 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 Grand Lake St. Marys - West Embankment last inspected?
Grand Lake St. Marys - West Embankment was last inspected on November 5, 2019. Inspection dates indicate when a formal review occurred, not the results of that inspection.