Mcwilliams Reservoir is an earth dam located in Garfield County, Montana, built in 1965. It carries a Low hazard potential classification.
Dam profile
NID height · 34 ft34 ft tall and 1,125 ft long, taller than 78% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Mcwilliams Reservoir
The primary purpose of Mcwilliams Reservoir is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Gary/john/mabel Johnson (private). It impounds the Red Butte Creek near No Town.
The dam stands 34 feet tall and stretches 1,125 feet across, and has a maximum storage capacity of 1,080 acre-feet. Completed in 1965, the structure is well into its service life at over 50 years old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life.
At 34 feet, this dam is taller than 78% of dams nationwide.
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Location
| State | Montana |
| County | Garfield |
| Nearest City | No Town |
| River/Stream | Red Butte Creek |
| Coordinates | 46.95400, -106.41780 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 34 ft |
| Dam Height | 34 ft |
| Dam Length | 1,125 ft |
| Year Completed | 1965 (61 years old) |
Storage & Hydraulics
| NID Storage | 1,080 acre-ft |
| Max Storage | 1,080 acre-ft |
| Normal Storage | 742 acre-ft |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Gary/john/mabel Johnson |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT00466 |
| Federal ID | MT00466 |
| More Info | State Dam Safety Program |