Pierce Lake Dam

WILLOW CREEK· Winnebago, Illinois· Built 1960· Earth· 46 ft tall
High Hazard Recreation State Government

Key Takeaway

Pierce Lake Dam is classified as high hazard in Illinois. It was completed in 1960 and is 66 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 46 ft (taller than 88.9% in IL)
Dam Length470 ft
Dam TypeEarth
Max Storage4.8K acre-ft
Normal Storage2.7K acre-ft
Surface Area162 acres
Drainage Area13 sq mi
Max Discharge30,000 cfs
Year Completed1960 (66 years old)
NID IDIL01011

Safety Information

High Hazard

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?

Emergency Action Plan: Yes
Last Inspection: July 15, 2020
State Regulated: Yes
Regulatory Agency: IDNR

Ownership

ILLINOIS DEPARTMENT OF NATURAL RESOURCES

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Pierce Lake Dam?

Pierce Lake 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 Pierce Lake Dam?

Pierce Lake 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 Pierce Lake Dam built?

Pierce Lake Dam was completed in 1960, making it 66 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 Pierce Lake Dam?

Pierce Lake 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 Pierce Lake Dam?

Pierce Lake Dam has a dam height of 46 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 Pierce Lake Dam last inspected?

Pierce Lake Dam was last inspected on July 15, 2020. Inspection dates indicate when a formal review occurred, not the results of that inspection.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.