Lake Mendota Dam
Key Takeaway
Lake Mendota Dam is classified as high hazard in Illinois. It was completed in 1890 and is 136 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 | 17 ft (taller than 22.3% in IL) |
| Dam Length | 2,430 ft |
| Dam Type | Earth |
| Max Storage | 246 acre-ft |
| Normal Storage | 163 acre-ft |
| Surface Area | 17 acres |
| Drainage Area | 221 sq mi |
| Max Discharge | 860 cfs |
| Year Completed | 1890 (136 years old) |
| NID ID | IL00223 |
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
CITY OF MENDOTA
Local Government
Nearby Dams
Frequently Asked Questions
What is the hazard classification of Lake Mendota Dam?
Lake Mendota Dam 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 Lake Mendota Dam?
Lake Mendota Dam is owned by CITY OF MENDOTA (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Lake Mendota Dam built?
Lake Mendota Dam was completed in 1890, making it 136 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 Lake Mendota Dam?
Lake Mendota Dam 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 Lake Mendota Dam?
Lake Mendota Dam has a dam height of 17 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 Lake Mendota Dam last inspected?
Lake Mendota Dam was last inspected on May 14, 2019. Inspection dates indicate when a formal review occurred, not the results of that inspection.