Four Mile
Four Mile is an earth dam located in Johnson County, Wyoming, built in 1944. It carries a Low hazard potential classification and has a fair condition assessment.
About Four Mile
The primary purpose of Four Mile is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Jim Forbes (private). It impounds the Four Mile Creek near Arvada.
The dam stands 18 feet tall and stretches 700 feet across, creates a reservoir covering 12 acres, and has a maximum storage capacity of 136 acre-feet. Completed in 1944, the structure is well-established, with more than 75 years of service.
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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. The most recent inspection on record was 06/29/2022.
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Location
| State | Wyoming |
| County | Johnson |
| Nearest City | Arvada |
| River/Stream | Four Mile Creek |
| Coordinates | 43.80530, -106.47410 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 18 ft |
| Dam Height | 18 ft |
| Dam Length | 700 ft |
| Year Completed | 1944 (82 years old) |
Storage & Hydraulics
| NID Storage | 136 acre-ft |
| Max Storage | 136 acre-ft |
| Normal Storage | 59 acre-ft |
| Surface Area | 12 acres |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | JIM FORBES |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 06/29/2022 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | WY00994 |
| Federal ID | WY00994 |
| More Info | State Dam Safety Program |