Yellow Water Dike
Yellow Water Dike is a rockfill dam located in Petroleum County, Montana, built in 1938. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Yellow Water Dike
The primary purpose of Yellow Water Dike is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by State Water Projects (state). It impounds the Yellow Water Creek near Mosby.
The dam stands 11 feet tall and stretches 545 feet across, creates a reservoir covering 450 acres, has a maximum storage capacity of 5,100 acre-feet, and collects water from a drainage area of 55 square miles. Completed in 1938, the structure is well-established, with more than 75 years of service.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 08/13/2024.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Montana dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Montana |
| County | Petroleum |
| Nearest City | Mosby |
| River/Stream | Yellow Water Creek |
| Coordinates | 46.90720, -108.48360 |
Physical Characteristics
| Dam Type | Rockfill |
| NID Height | 11 ft |
| Dam Height | 11 ft |
| Dam Length | 545 ft |
| Year Completed | 1938 (88 years old) |
Storage & Hydraulics
| NID Storage | 5,100 acre-ft |
| Max Storage | 5,100 acre-ft |
| Normal Storage | 1,500 acre-ft |
| Surface Area | 450 acres |
| Drainage Area | 55 sq mi |
| Max Discharge | 180 cfs |
Ownership & Safety
| Purpose | Irrigation |
| Owner | STATE WATER PROJECTS |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/13/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MT03205 |
| Federal ID | MT00012S001 |
| More Info | State Dam Safety Program |