Swan Falls

Snake River· Ada, Idaho· Built 1901· Concrete· 88 ft tall
High Hazard Hydroelectric Recreation Private

Key Takeaway

Swan Falls is classified as high hazard in Idaho. It was completed in 1901 and is 125 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 88 ft (taller than 91.3% in ID)
Dam Length1,150 ft
Dam TypeConcrete
Normal Storage7.4K acre-ft
Surface Area1,525 acres
Drainage Area41,900 sq mi
Max Discharge105,112 cfs
Year Completed1901 (125 years old)
NID IDID00049

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: April 5, 2023
State Regulated: Yes
Regulatory Agency: IDWR

Ownership

Idaho Power Company

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Swan Falls?

Swan Falls 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 Swan Falls?

Swan Falls is owned by Idaho Power Company (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Swan Falls built?

Swan Falls was completed in 1901, making it 125 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 Swan Falls?

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

How tall is Swan Falls?

Swan Falls has a dam height of 88 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 Swan Falls last inspected?

Swan Falls was last inspected on April 5, 2023. 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.