Winchester

LAPWAI CREEK CLEARWATER RIVER· Lewis, Idaho· Built 1910· 40 ft tall
High Hazard Other State Government

Key Takeaway

Winchester is classified as high hazard in Idaho. It was completed in 1910 and is 116 years old. Its primary use is other. 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 40 ft (taller than 70.7% in ID)
Dam Length218 ft
Normal Storage1.4K acre-ft
Surface Area98 acres
Drainage Area13 sq mi
Max Discharge1,100 cfs
Year Completed1910 (116 years old)
Year Modified2001
NID IDID00148

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: May 23, 2019
State Regulated: Yes
Regulatory Agency: IDWR

Ownership

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Winchester?

Winchester 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 Winchester?

Winchester is owned by information not available (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Winchester built?

Winchester was completed in 1910, making it 116 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 Winchester?

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

How tall is Winchester?

Winchester has a dam height of 40 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 Winchester last inspected?

Winchester was last inspected on May 23, 2019. 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.