Three Mile Reservoir Dam
Key Takeaway
Three Mile Reservoir Dam is classified as significant hazard in Iowa. It was completed in 1995 and is 31 years old. Its primary use is flood risk reduction. Significant hazard means failure could cause economic or environmental damage. Learn more.
Physical Details
| Dam Height | 63 ft (taller than 99% in IA) |
| Dam Length | 1,850 ft |
| Dam Type | Earth |
| Max Storage | 30.0K acre-ft |
| Normal Storage | 14.1K acre-ft |
| Surface Area | 880 acres |
| Drainage Area | 36 sq mi |
| Max Discharge | 0 cfs |
| Year Completed | 1995 (31 years old) |
| NID ID | IA02944 |
Safety Information
No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
Iowa Department of Natural Resources
State Government
Nearby Dams
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Low Hazard 35 ftTwelve Mile Creek Watershed Site 58
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Low Hazard 28 ftThree Mile Creek Watershed Site 14-G-1
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Low Hazard 31 ftThree Mile Lake Sediment Dam
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Low Hazard 26 ftFrequently Asked Questions
What is the hazard classification of Three Mile Reservoir Dam?
Three Mile Reservoir Dam is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Three Mile Reservoir Dam?
Three Mile Reservoir Dam is owned by Iowa Department of Natural Resources (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Three Mile Reservoir Dam built?
Three Mile Reservoir Dam was completed in 1995, making it 31 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 Three Mile Reservoir Dam?
Three Mile Reservoir Dam serves the following purposes: Flood Risk Reduction, Recreation, Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Three Mile Reservoir Dam?
Three Mile Reservoir Dam has a dam height of 63 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 Three Mile Reservoir Dam last inspected?
Three Mile Reservoir Dam was last inspected on June 10, 2020. Inspection dates indicate when a formal review occurred, not the results of that inspection.