Diamond #1 is an earth dam located in Custer County, Montana, built in 1958. It carries a Low hazard potential classification.
Dam profile
NID height · 15 ft15 ft tall and 200 ft long. 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 Diamond #1
The primary purpose of Diamond #1 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 Diamond Two Ranch (private). It impounds the Spring Creek near Shirley.
The dam stands 15 feet tall and stretches 200 feet across, has a maximum storage capacity of 51 acre-feet, and collects water from a drainage area of 5 square miles. Completed in 1958, 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.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Montana |
| County | Custer |
| Nearest City | Shirley |
| River/Stream | Spring Creek |
| Coordinates | 46.51970, -105.66260 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 15 ft |
| Dam Height | 15 ft |
| Dam Length | 200 ft |
| Year Completed | 1958 (68 years old) |
Storage & Hydraulics
| NID Storage | 51 acre-ft |
| Max Storage | 51 acre-ft |
| Normal Storage | 20 acre-ft |
| Drainage Area | 5 sq mi |
| Max Discharge | 500 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Fire Protection, Stock, Or Small Fish Pond |
| Owner | Diamond Two Ranch |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MT01771 |
| Federal ID | MT01771 |
| More Info | State Dam Safety Program |