Marcalus Manufacturing Company Dam
Marcalus Manufacturing Company Dam is a concrete dam located in Hampshire County, Massachusetts. It carries a High hazard potential classification and has a fair condition assessment.
About Marcalus Manufacturing Company Dam
The primary purpose of Marcalus Manufacturing Company Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by The Mill At Stoney Brook Condo Association (private). It impounds the Stoney Brook near S. Hadley.
The dam stands 27 feet tall and stretches 84 feet across, creates a reservoir covering 1 acres, has a maximum storage capacity of 19 acre-feet, and collects water from a drainage area of 19 square miles.
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 08/22/2023.
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 Massachusetts 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 | Massachusetts |
| County | Hampshire |
| Nearest City | S. Hadley |
| River/Stream | Stoney Brook |
| Coordinates | 42.24868, -72.57963 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 27 ft |
| Dam Length | 84 ft |
Storage & Hydraulics
| NID Storage | 19 acre-ft |
| Max Storage | 19 acre-ft |
| Normal Storage | 11 acre-ft |
| Surface Area | 1 acres |
| Drainage Area | 19 sq mi |
| Max Discharge | 1,450 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Recreation |
| Owner | The Mill At Stoney Brook Condo Association |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 08/22/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00585 |
| Federal ID | MA00585 |
| More Info | State Dam Safety Program |