New Richmond Mills is a gravity dam located in St. Croix County, Wisconsin, built in 1812. It carries a High hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 19 ft19 ft tall and 325 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic concrete gravity section and the water level is illustrative.
About New Richmond Mills
The primary purpose of New Richmond Mills is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by City of New Richmond (local government). It impounds the Willow River near New Richmond.
The dam stands 19 feet tall and stretches 325 feet across, creates a reservoir covering 236 acres, has a maximum storage capacity of 1,500 acre-feet, and collects water from a drainage area of 146 square miles. Completed in 1812, the structure is one of the older dams in the region, with over a century and a half of service.
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 08/10/2021.
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 Wisconsin 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 | Wisconsin |
| County | St. Croix |
| Nearest City | New Richmond |
| River/Stream | Willow River |
| Coordinates | 45.12285, -92.53899 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 19 ft |
| Dam Height | 19 ft |
| Dam Length | 325 ft |
| Year Completed | 1812 (214 years old) |
Storage & Hydraulics
| NID Storage | 1,500 acre-ft |
| Max Storage | 1,500 acre-ft |
| Normal Storage | 826 acre-ft |
| Surface Area | 236 acres |
| Drainage Area | 146 sq mi |
| Max Discharge | 4,600 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Recreation |
| Owner | City of New Richmond |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 08/10/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WI00188 |
| Federal ID | WI00188 |
| More Info | State Dam Safety Program |