Tin Cup Lake (powell)
Tin Cup Lake (powell) is an earth dam located in Powell County, Montana, built in 1965. It carries a High hazard potential classification and has a fair condition assessment.
About Tin Cup Lake (powell)
The primary purpose of Tin Cup Lake (powell) is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by State Of Montana, D.o.c. (state). It impounds the Tin Cup Joe Creek near Deer Lodge.
The dam stands 19 feet tall and stretches 600 feet across, creates a reservoir covering 19 acres, has a maximum storage capacity of 229 acre-feet, and collects water from a drainage area of 8 square miles. Completed in 1965, the structure is well into its service life at over 50 years old.
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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 06/19/2024.
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 | Powell |
| Nearest City | Deer Lodge |
| River/Stream | Tin Cup Joe Creek |
| Coordinates | 46.38860, -112.85460 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 19 ft |
| Dam Height | 19 ft |
| Dam Length | 600 ft |
| Year Completed | 1965 (61 years old) |
Storage & Hydraulics
| NID Storage | 229 acre-ft |
| Max Storage | 229 acre-ft |
| Normal Storage | 114 acre-ft |
| Surface Area | 19 acres |
| Drainage Area | 8 sq mi |
| Max Discharge | 530 cfs |
Ownership & Safety
| Purpose | Irrigation |
| Owner | STATE OF MONTANA, D.O.C. |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 06/19/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MT01387 |
| Federal ID | MT01387 |
| More Info | State Dam Safety Program |