Grizzly Gulch Tailings Dam is an earth dam located in Lawrence County, South Dakota, built in 1998. It carries a High hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 380 ft380 ft tall and 2,000 ft long, taller than 99% of U.S. dams with a recorded height. Height is drawn to scale against the Statue of Liberty, 305 ft ground to torch; the profile is a generic embankment section and the water level is illustrative.
About Grizzly Gulch Tailings Dam
The primary purpose of Grizzly Gulch Tailings Dam is tailings. Tailings dams contain waste material from mining operations — typically a slurry of finely ground rock left over after valuable minerals have been extracted. These structures require ongoing monitoring because tailings can contain heavy metals and other contaminants. The dam is owned by Homestake Mining Company (private). It impounds the Grizzly Gulch near Pluma.
The dam stands 380 feet tall and stretches 2,000 feet across, creates a reservoir covering 304 acres, has a maximum storage capacity of 20,200 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1998, the structure is 28 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 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 09/06/2022.
At 380 feet, this dam is taller than 99% of all dams in the United States.
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 South Dakota 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 | South Dakota |
| County | Lawrence |
| Nearest City | Pluma |
| River/Stream | Grizzly Gulch |
| Coordinates | 44.33333, -103.73999 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 380 ft |
| Dam Height | 380 ft |
| Dam Length | 2,000 ft |
| Year Completed | 1998 (28 years old) |
Storage & Hydraulics
| NID Storage | 20,200 acre-ft |
| Max Storage | 20,200 acre-ft |
| Normal Storage | 2,100 acre-ft |
| Surface Area | 304 acres |
| Drainage Area | 2 sq mi |
Ownership & Safety
| Purpose | Tailings |
| Owner | Homestake Mining Company |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/06/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | SD02255 |
| Federal ID | SD02255 |
| More Info | State Dam Safety Program |