Agnes Lake
Agnes Lake is an earth dam located in Beaverhead County, Montana, built in 1928. It carries a High hazard potential classification.
About Agnes Lake
The primary purpose of Agnes Lake is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Burk Ranches Inc (private). It impounds the Agnes Creek near Glen.
The dam stands 13 feet tall and stretches 174 feet across, creates a reservoir covering 99 acres, has a maximum storage capacity of 1,900 acre-feet, and collects water from a drainage area of 3 square miles. Completed in 1928, 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. Notably, no emergency action plan is currently on file for this high-hazard dam.
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 | Beaverhead |
| Nearest City | Glen |
| River/Stream | Agnes Creek |
| Coordinates | 45.51579, -112.83696 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 13 ft |
| Dam Height | 13 ft |
| Dam Length | 174 ft |
| Year Completed | 1928 (98 years old) |
Storage & Hydraulics
| NID Storage | 1,900 acre-ft |
| Max Storage | 1,900 acre-ft |
| Normal Storage | 790 acre-ft |
| Surface Area | 99 acres |
| Drainage Area | 3 sq mi |
| Max Discharge | 560 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | BURK RANCHES INC |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Not Rated |
| Emergency Action Plan | No |
Identifiers
| NID ID | MT00817 |
| Federal ID | MT00817 |
| More Info | State Dam Safety Program |