Tin Cup Lake (Powell)

TIN CUP JOE CREEK· Powell, Montana· Built 1965· Earth· 19 ft tall
High Hazard Irrigation State Government

Key Takeaway

Tin Cup Lake (Powell) is classified as high hazard in Montana. It was completed in 1965 and is 61 years old. Its primary use is irrigation. 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 19 ft (taller than 42.9% in MT)
Dam Length600 ft
Dam TypeEarth
Max Storage229 acre-ft
Normal Storage114 acre-ft
Surface Area19 acres
Drainage Area9 sq mi
Max Discharge530 cfs
Year Completed1965 (61 years old)
Year Modified2001
NID IDMT01387

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: June 25, 2019
State Regulated: Yes
Regulatory Agency: DNRC

Ownership

STATE OF MONTANA, D.O.C.

State Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Tin Cup Lake (Powell)?

Tin Cup Lake (Powell) 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 Tin Cup Lake (Powell)?

Tin Cup Lake (Powell) is owned by STATE OF MONTANA, D.O.C. (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Tin Cup Lake (Powell) built?

Tin Cup Lake (Powell) was completed in 1965, making it 61 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 Tin Cup Lake (Powell)?

Tin Cup Lake (Powell) serves the following purposes: Irrigation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Tin Cup Lake (Powell)?

Tin Cup Lake (Powell) has a dam height of 19 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 Tin Cup Lake (Powell) last inspected?

Tin Cup Lake (Powell) was last inspected on June 25, 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.