Posy No. 1

POSY CREEK· Johnson, Wyoming· Built 1995· Earth· 51 ft tall

Key Takeaway

Posy No. 1 is classified as low hazard in Wyoming. It was completed in 1995 and is 31 years old. Its primary use is irrigation.

Physical Details

Dam Height 51 ft (taller than 94.3% in WY)
Dam Length1,788 ft
Dam TypeEarth
Max Storage2.2K acre-ft
Normal Storage1.5K acre-ft
Surface Area125 acres
Drainage Area16 sq mi
Max Discharge6,650 cfs
Year Completed1995 (31 years old)
NID IDWY02048

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 21, 2020
State Regulated: Yes
Regulatory Agency: SEO

Ownership

TTT RANCH CO

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Posy No. 1?

Posy No. 1 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 Posy No. 1?

Posy No. 1 is owned by TTT RANCH CO (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Posy No. 1 built?

Posy No. 1 was completed in 1995, making it 31 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 Posy No. 1?

Posy No. 1 serves the following purposes: Irrigation, Fire Protection, Stock, Or Small Fish Pond. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Posy No. 1?

Posy No. 1 has a dam height of 51 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 Posy No. 1 last inspected?

Posy No. 1 was last inspected on July 21, 2020. 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.