Rieger

SOUTH FORK COTTONWOOD CREEK· Fallon, Montana· Built 1958· Earth· 21 ft tall
Significant Hazard Irrigation Private

Key Takeaway

Rieger is classified as significant hazard in Montana. It was completed in 1958 and is 68 years old. Its primary use is irrigation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 21 ft (taller than 61.7% in MT)
Dam Length300 ft
Dam TypeEarth
Normal Storage93 acre-ft
Surface Area13 acres
Drainage Area6,976 sq mi
Max Discharge0 cfs
Year Completed1958 (68 years old)
Year Modified2015
NID IDMT01043

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
State Regulated: Yes
Regulatory Agency: DNRC

Ownership

DONALD RIEGER

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Rieger?

Rieger is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Rieger?

Rieger is owned by DONALD RIEGER (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Rieger built?

Rieger was completed in 1958, making it 68 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 Rieger?

Rieger 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 Rieger?

Rieger has a dam height of 21 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.

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.