Cold Brook Dam
Cold Brook Dam is an earth dam located in Fall River County, South Dakota, built in 1953. It carries a High hazard potential classification.
About Cold Brook Dam
The primary purpose of Cold Brook Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Usace - Omaha District (federal). It impounds the Cold Brook near Hot Springs.
The dam stands 130 feet tall and stretches 925 feet across, creates a reservoir covering 36 acres, has a maximum storage capacity of 7,200 acre-feet, and collects water from a drainage area of 71 square miles. Completed in 1953, the structure is well into its service life at over 50 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. An emergency action plan is in place for this dam. The most recent inspection on record was 07/17/2025.
At 130 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 | Fall River |
| Nearest City | Hot Springs |
| River/Stream | Cold Brook |
| Coordinates | 43.45342, -103.48909 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 130 ft |
| Dam Length | 925 ft |
| Year Completed | 1953 (73 years old) |
Storage & Hydraulics
| NID Storage | 7,200 acre-ft |
| Max Storage | 7,200 acre-ft |
| Normal Storage | 520 acre-ft |
| Surface Area | 36 acres |
| Drainage Area | 71 sq mi |
| Max Discharge | 80,600 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | USACE - Omaha District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 07/17/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | SD01097 |
| Federal ID | SD01097 |
| More Info | State Dam Safety Program |