Iwan No.1
Key Takeaway
Iwan No.1 is classified as low hazard in South Dakota. It was completed in 1973 and is 53 years old. Its primary use is fire protection.
Physical Details
| Dam Height | 28 ft (taller than 77.7% in SD) |
| Dam Length | 300 ft |
| Dam Type | Earth |
| Max Storage | 20 acre-ft |
| Normal Storage | 14 acre-ft |
| Max Discharge | 435 cfs |
| Year Completed | 1973 (53 years old) |
| NID ID | SD01313 |
Safety Information
No probable loss of human life and low economic/environmental losses expected.
Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?
Ownership
IWAN
Private
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Low Hazard 29 ftFrequently Asked Questions
What is the hazard classification of Iwan No.1?
Iwan No.1 is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.
Who owns and operates Iwan No.1?
Iwan No.1 is owned by IWAN (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Iwan No.1 built?
Iwan No.1 was completed in 1973, making it 53 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 Iwan No.1?
Iwan No.1 serves the following purposes: Fire Protection, Stock, Or Small Fish Pond, Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Iwan No.1?
Iwan No.1 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.