Steffensen

BILLY CREEK· Johnson, Wyoming· Built 1950· Earth· 39 ft tall
Low Hazard Irrigation Private

Key Takeaway

Steffensen is classified as low hazard in Wyoming. It was completed in 1950 and is 76 years old. Its primary use is irrigation.

Physical Details

Dam Height 39 ft (taller than 85.9% in WY)
Dam Length340 ft
Dam TypeEarth
Max Storage238 acre-ft
Normal Storage168 acre-ft
Surface Area53 acres
Drainage Area0 sq mi
Max Discharge0 cfs
Year Completed1950 (76 years old)
NID IDWY00787

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

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

Emergency Action Plan: No
Last Inspection: July 31, 2019
State Regulated: Yes
Regulatory Agency: SEO

Ownership

JAMES R. PURDY REVOCABLE TRUST

Private

Nearby Dams

Steffenson No. 2

Johnson, WY

Low Hazard 41 ft

Dry Poison Irrigation

Johnson, WY

Low Hazard 32 ft

Poison Creek No. 1

Johnson, WY

Low Hazard 30 ft

Basch

Johnson, WY

Low Hazard 34 ft

Gammon

Johnson, WY

Low Hazard 24 ft

Muddy Guard No. 2 South Dam

Johnson, WY

High Hazard 57 ft

Muddy Guard No. 1

Johnson, WY

Low Hazard 50 ft

Muddy Guard No. 2 North Dam

Johnson, WY

Significant Hazard 102 ft

Frequently Asked Questions

What is the hazard classification of Steffensen?

Steffensen is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Steffensen?

Steffensen is owned by JAMES R. PURDY REVOCABLE TRUST (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Steffensen built?

Steffensen was completed in 1950, making it 76 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 Steffensen?

Steffensen 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 Steffensen?

Steffensen has a dam height of 39 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 Steffensen last inspected?

Steffensen was last inspected on July 31, 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.