Delmoe Lake Dam

BIG PIPESTONE CREEK· Jefferson, Montana· Built 1914· Earth· 60 ft tall
High Hazard Irrigation Private

Key Takeaway

Delmoe Lake Dam is classified as high hazard in Montana. It was completed in 1914 and is 112 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 60 ft (taller than 97.6% in MT)
Dam Length290 ft
Dam TypeEarth
Max Storage9.9K acre-ft
Normal Storage6.6K acre-ft
Surface Area310 acres
Drainage Area23 sq mi
Max Discharge1,900 cfs
Year Completed1914 (112 years old)
NID IDMT00117

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: October 16, 2023
State Regulated: Yes
Regulatory Agency: DNRC

Ownership

PIPESTONE WATER USERS

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Delmoe Lake Dam?

Delmoe 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 Delmoe Lake Dam?

Delmoe Lake Dam is owned by PIPESTONE WATER USERS (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Delmoe Lake Dam built?

Delmoe Lake Dam 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 Delmoe Lake Dam?

Delmoe Lake Dam 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 Delmoe Lake Dam?

Delmoe Lake Dam has a dam height of 60 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 Delmoe Lake Dam last inspected?

Delmoe Lake Dam was last inspected on October 16, 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.