Gridley Dam
Key Takeaway
Gridley Dam is classified as low hazard in Illinois. It was completed in 1998 and is 28 years old. Its primary use is recreation.
Physical Details
| Dam Height | 51 ft (taller than 92.4% in IL) |
| Dam Length | 414 ft |
| Dam Type | Earth |
| Max Storage | 475 acre-ft |
| Normal Storage | 277 acre-ft |
| Surface Area | 25 acres |
| Drainage Area | 0 sq mi |
| Year Completed | 1998 (28 years old) |
| NID ID | IL50398 |
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
ILLINOIS DEPARTMENT OF NATURAL RESOURCES
State Government
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Significant Hazard 26 ftFrequently Asked Questions
What is the hazard classification of Gridley Dam?
Gridley Dam 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 Gridley Dam?
Gridley Dam is owned by ILLINOIS DEPARTMENT OF NATURAL RESOURCES (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.
When was Gridley Dam built?
Gridley Dam was completed in 1998, making it 28 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 Gridley Dam?
Gridley 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 Gridley Dam?
Gridley Dam has a dam height of 51 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 Gridley Dam last inspected?
Gridley Dam was last inspected on May 9, 2022. Inspection dates indicate when a formal review occurred, not the results of that inspection.