John Ball Reservoir
John Ball Reservoir is an earth dam located in McCone County, Montana, built in 1935. It carries a Significant hazard potential classification.
About John Ball Reservoir
The primary purpose of John Ball Reservoir is fire protection, stock, or small fish pond. The dam maintains a small impoundment used for fire suppression, livestock watering, or as a fish pond. The dam is owned by Lyle E Nelson (private). It impounds the Tr-south Fork Rock Creek near No Town.
The dam stands 16 feet tall and stretches 360 feet across, has a maximum storage capacity of 145 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1935, the structure is well-established, with more than 75 years of service.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Montana |
| County | McCone |
| Nearest City | No Town |
| River/Stream | Tr-south Fork Rock Creek |
| Coordinates | 47.72070, -106.13850 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 16 ft |
| Dam Height | 16 ft |
| Dam Length | 360 ft |
| Year Completed | 1935 (91 years old) |
Storage & Hydraulics
| NID Storage | 145 acre-ft |
| Max Storage | 145 acre-ft |
| Normal Storage | 61 acre-ft |
| Drainage Area | 1 sq mi |
| Max Discharge | 1,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Fire Protection, Stock, Or Small Fish Pond |
| Owner | LYLE E NELSON |
| Owner Type | Private |
| Hazard Classification | Significant |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT00482 |
| Federal ID | MT00482 |
| More Info | State Dam Safety Program |