Rock Rapids Milldam
Key Takeaway
Rock Rapids Milldam is classified as low hazard in Iowa. It was completed in 1931 and is 95 years old. Its primary use is water supply.
Physical Details
| Dam Height | 7 ft |
| Dam Length | 220 ft |
| Dam Type | Gravity |
| Max Storage | 75 acre-ft |
| Normal Storage | 49 acre-ft |
| Surface Area | 10 acres |
| Drainage Area | 777 sq mi |
| Max Discharge | 0 cfs |
| Year Completed | 1931 (95 years old) |
| NID ID | IA01317 |
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
City of Rock Rapids
Local Government
Frequently Asked Questions
What is the hazard classification of Rock Rapids Milldam?
Rock Rapids Milldam 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 Rock Rapids Milldam?
Rock Rapids Milldam is owned by City of Rock Rapids (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Rock Rapids Milldam built?
Rock Rapids Milldam was completed in 1931, making it 95 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 Rock Rapids Milldam?
Rock Rapids Milldam serves the following purposes: Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.
How tall is Rock Rapids Milldam?
Rock Rapids Milldam has a dam height of 7 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 Rock Rapids Milldam last inspected?
Rock Rapids Milldam was last inspected on October 18, 1989. Inspection dates indicate when a formal review occurred, not the results of that inspection.