Gammon

Gammon is an earth dam located in Johnson County, Wyoming, built in 1974. It carries a Low hazard potential classification and has a poor condition assessment.

About Gammon

The primary purpose of Gammon is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by T-a Ranch, Llp (private). It impounds the T. A. Creek.

The dam stands 34 feet tall and stretches 1,120 feet across, creates a reservoir covering 8 acres, has a maximum storage capacity of 86 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1974, the structure is well into its service life at over 50 years old.

This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. The most recent inspection on record was 06/21/2021.

At 34 feet, this dam is taller than 80% of dams nationwide.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

Low HazardPoor ConditionEmergency Action Plan: Not Required

Location

StateWyoming
CountyJohnson
River/StreamT. A. Creek
Coordinates44.15270, -106.69590

Physical Characteristics

Dam TypeEarth
NID Height34 ft
Dam Height24 ft
Dam Length1,120 ft
Year Completed1974 (52 years old)

Storage & Hydraulics

NID Storage86 acre-ft
Max Storage86 acre-ft
Normal Storage46 acre-ft
Surface Area8 acres
Drainage Area0 sq mi
Max Discharge271 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeIrrigation
OwnerT-A RANCH, LLP
Owner TypePrivate
Hazard ClassificationLow
Condition AssessmentPoor
Last Inspection06/21/2021
Emergency Action PlanNot Required

Identifiers

NID IDWY01647
Federal IDWY01647
More InfoState Dam Safety Program

Nearby Dams