Prairie Du Sac

Wisconsin River· Sauk, Wisconsin· Built 1914· Gravity· 25 ft tall
High Hazard Hydroelectric Public Utility

Key Takeaway

Prairie Du Sac is classified as high hazard in Wisconsin. It was completed in 1914 and is 112 years old. Its primary use is hydroelectric. 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 25 ft (taller than 70.9% in WI)
Dam Length3,247 ft
Dam TypeGravity
Max Storage193.2K acre-ft
Normal Storage120.0K acre-ft
Surface Area9,000 acres
Drainage Area9,180 sq mi
Max Discharge251,990 cfs
Year Completed1914 (112 years old)
NID IDWI00029

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: August 9, 2022
State Regulated: No

Ownership

Wisconsin Power and Light Company

Public Utility

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Prairie Du Sac?

Prairie Du Sac 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 Prairie Du Sac?

Prairie Du Sac is owned by Wisconsin Power and Light Company (Public Utility). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Prairie Du Sac built?

Prairie Du Sac was completed in 1914, making it 112 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 Prairie Du Sac?

Prairie Du Sac serves the following purposes: Hydroelectric. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Prairie Du Sac?

Prairie Du Sac has a dam height of 25 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 Prairie Du Sac last inspected?

Prairie Du Sac was last inspected on August 9, 2022. 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.