Willow Mill Dam
Willow Mill Dam is a stone dam located in Berkshire County, Massachusetts, built in 1872. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Willow Mill Dam
Willow Mill Dam is a dam in Berkshire, Massachusetts. The dam is owned by Onyx Specialty Papers, Inc. (private). It impounds the Housatonic River near Lee.
The dam stands 24 feet tall and stretches 150 feet across, creates a reservoir covering 13 acres, has a maximum storage capacity of 50 acre-feet, and collects water from a drainage area of 243 square miles. Completed in 1872, the structure is one of the older dams in the region, with over a century and a half of service.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. 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 07/29/2022.
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Location
| State | Massachusetts |
| County | Berkshire |
| Nearest City | Lee |
| River/Stream | Housatonic River |
| Coordinates | 42.27606, -73.28470 |
Physical Characteristics
| Dam Type | Stone |
| NID Height | 24 ft |
| Dam Length | 150 ft |
| Year Completed | 1872 (154 years old) |
Storage & Hydraulics
| NID Storage | 50 acre-ft |
| Max Storage | 50 acre-ft |
| Normal Storage | 50 acre-ft |
| Surface Area | 13 acres |
| Drainage Area | 243 sq mi |
| Max Discharge | 13,200 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Other |
| Owner | Onyx Specialty Papers, Inc. |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 07/29/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00262 |
| Federal ID | MA00262 |
| More Info | State Dam Safety Program |