Hanson Creek Dam
Hanson Creek Dam is an earth dam located in Fergus County, Montana, built in 1974. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Hanson Creek Dam
The primary purpose of Hanson Creek Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by City Of Lewistown (local government). It impounds the Hanson Creek near Lewistown.
The dam stands 72 feet tall and stretches 759 feet across, creates a reservoir covering 32 acres, has a maximum storage capacity of 860 acre-feet, and collects water from a drainage area of 9 square miles. Completed in 1974, 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 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 06/15/2020.
At 72 feet, this dam is taller than 96% 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 Montana 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 | Montana |
| County | Fergus |
| Nearest City | Lewistown |
| River/Stream | Hanson Creek |
| Coordinates | 46.99900, -109.33620 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 72 ft |
| Dam Height | 61 ft |
| Dam Length | 759 ft |
| Year Completed | 1974 (52 years old) |
Storage & Hydraulics
| NID Storage | 860 acre-ft |
| Max Storage | 860 acre-ft |
| Normal Storage | 180 acre-ft |
| Surface Area | 32 acres |
| Drainage Area | 9 sq mi |
| Max Discharge | 14,500 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | CITY OF LEWISTOWN |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 06/15/2020 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MT01570 |
| Federal ID | MT01570 |
| More Info | State Dam Safety Program |