Gammon

T. A. CREEK· Johnson, Wyoming· Built 1974· Earth· 24 ft tall
Low Hazard Irrigation Flood Risk Reduction Private

Key Takeaway

Gammon is classified as low hazard in Wyoming. It was completed in 1974 and is 52 years old. Its primary use is irrigation.

Physical Details

Dam Height 24 ft (taller than 35.6% in WY)
Dam Length1,120 ft
Dam TypeEarth
Max Storage86 acre-ft
Normal Storage46 acre-ft
Surface Area8 acres
Drainage Area1 sq mi
Max Discharge271 cfs
Year Completed1974 (52 years old)
NID IDWY01647

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: June 21, 2021
State Regulated: Yes
Regulatory Agency: SEO

Ownership

T-A RANCH, LLP

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Gammon?

Gammon 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 Gammon?

Gammon is owned by T-A RANCH, LLP (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Gammon built?

Gammon was completed in 1974, making it 52 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 Gammon?

Gammon serves the following purposes: Irrigation, Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Gammon?

Gammon has a dam height of 24 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 Gammon last inspected?

Gammon was last inspected on June 21, 2021. 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.