Mott Watershed Dam
Mott Watershed Dam is an earth dam located in Hettinger County, North Dakota, built in 1969. It carries a High hazard potential classification and has a fair condition assessment.
About Mott Watershed Dam
The primary purpose of Mott Watershed 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 Hettinger County Wrb (local government). It impounds the Cannonball-tr near Mott.
The dam stands 47 feet tall and stretches 2,218 feet across, creates a reservoir covering 35 acres, has a maximum storage capacity of 2,811 acre-feet, and collects water from a drainage area of 3 square miles. Completed in 1969, 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. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 09/21/2021.
At 47 feet, this dam is taller than 92% of dams nationwide.
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 North 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 | North Dakota |
| County | Hettinger |
| Nearest City | Mott |
| River/Stream | Cannonball-tr |
| Coordinates | 46.38024, -102.32590 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 47 ft |
| Dam Height | 39 ft |
| Dam Length | 2,218 ft |
| Year Completed | 1969 (57 years old) |
Storage & Hydraulics
| NID Storage | 2,811 acre-ft |
| Max Storage | 2,811 acre-ft |
| Normal Storage | 120 acre-ft |
| Surface Area | 35 acres |
| Drainage Area | 3 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Hettinger County WRB |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 09/21/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | ND00080 |
| Federal ID | ND00080 |
| More Info | State Dam Safety Program |