Robertson No.1

BULL CREEK· Gregory, South Dakota· Built 1975· Earth· 30 ft tall
Significant Hazard Irrigation Private

Key Takeaway

Robertson No.1 is classified as significant hazard in South Dakota. It was completed in 1975 and is 51 years old. Its primary use is irrigation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 30 ft (taller than 85.2% in SD)
Dam Length1,500 ft
Dam TypeEarth
Max Storage2.0K acre-ft
Normal Storage1.2K acre-ft
Max Discharge5,000 cfs
Year Completed1975 (51 years old)
NID IDSD02190

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
Last Inspection: April 15, 1981
State Regulated: Yes
Regulatory Agency: DANR

Ownership

HAROLD ROBERTSON

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Robertson No.1?

Robertson No.1 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 Robertson No.1?

Robertson No.1 is owned by HAROLD ROBERTSON (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Robertson No.1 built?

Robertson No.1 was completed in 1975, making it 51 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 Robertson No.1?

Robertson No.1 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 Robertson No.1?

Robertson No.1 has a dam height of 30 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 Robertson No.1 last inspected?

Robertson No.1 was last inspected on April 15, 1981. 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.