Glacier Lake South Dam
Glacier Lake South Dam is a rockfill dam located in Carbon County, Montana, built in 1937. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Glacier Lake South Dam
The primary purpose of Glacier Lake South Dam 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 Rock near Red Lodge.
The dam stands 20 feet tall and stretches 253 feet across, creates a reservoir covering 151 acres, has a maximum storage capacity of 2,850 acre-feet, and collects water from a drainage area of 3 square miles. Completed in 1937, 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 09/21/2021.
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 | Carbon |
| Nearest City | Red Lodge |
| River/Stream | Rock |
| Coordinates | 45.03300, -109.53295 |
Physical Characteristics
| Dam Type | Rockfill |
| NID Height | 20 ft |
| Dam Height | 20 ft |
| Dam Length | 253 ft |
| Year Completed | 1937 (89 years old) |
Storage & Hydraulics
| NID Storage | 2,850 acre-ft |
| Max Storage | 2,850 acre-ft |
| Normal Storage | 1,345 acre-ft |
| Surface Area | 151 acres |
| Drainage Area | 3 sq mi |
| Max Discharge | 472 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | STATE WATER PROJECTS |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/21/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MT01446 |
| Federal ID | MT01446 |
| More Info | State Dam Safety Program |