Brock
Brock is an earth dam located in Johnson County, Wyoming, built in 1964. It carries a Low hazard potential classification and has a poor condition assessment.
About Brock
The primary purpose of Brock is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Gerald Joint Revocable Trust, Larry J & Cheryl A Gerald Trustees (private). It impounds the Cummings Creek near Buffalo.
The dam stands 34 feet tall and stretches 255 feet across, creates a reservoir covering 6 acres, and has a maximum storage capacity of 86 acre-feet. Completed in 1964, 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 05/20/2025.
At 34 feet, this dam is taller than 80% of dams nationwide.
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Location
| State | Wyoming |
| County | Johnson |
| Nearest City | Buffalo |
| River/Stream | Cummings Creek |
| Coordinates | 44.30570, -106.71440 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 34 ft |
| Dam Height | 25 ft |
| Dam Length | 255 ft |
| Year Completed | 1964 (62 years old) |
Storage & Hydraulics
| NID Storage | 86 acre-ft |
| Max Storage | 86 acre-ft |
| Normal Storage | 51 acre-ft |
| Surface Area | 6 acres |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | GERALD JOINT REVOCABLE TRUST, LARRY J & CHERYL A GERALD TRUSTEES |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Poor |
| Last Inspection | 05/20/2025 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | WY00710 |
| Federal ID | WY00710 |
| More Info | State Dam Safety Program |