Wachusett Reservoir South Dike
Wachusett Reservoir South Dike is an earth dam located in Worcester County, Massachusetts, built in 1906. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Wachusett Reservoir South Dike
The primary purpose of Wachusett Reservoir South Dike is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Ma Department Of Conservation & Recreation (state). It impounds the Nashua River near Clinton.
The dam stands 45 feet tall and stretches 1,100 feet across, creates a reservoir covering 4,160 acres, has a maximum storage capacity of 250,000 acre-feet, and collects water from a drainage area of 121 square miles. Completed in 1906, the structure is over a century 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 10/28/2022.
At 45 feet, this dam is taller than 91% 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 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 | Worcester |
| Nearest City | Clinton |
| River/Stream | Nashua River |
| Coordinates | 42.39086, -71.68942 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 45 ft |
| Dam Length | 1,100 ft |
| Year Completed | 1906 (120 years old) |
Storage & Hydraulics
| NID Storage | 250,000 acre-ft |
| Max Storage | 250,000 acre-ft |
| Normal Storage | 187,000 acre-ft |
| Surface Area | 4,160 acres |
| Drainage Area | 121 sq mi |
| Spillway Type | None |
Ownership & Safety
| Purpose | Water Supply |
| Owner | MA Department of Conservation & Recreation |
| Owner Type | State |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 10/28/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA03263 |
| Federal ID | MA00886S002 |
| More Info | State Dam Safety Program |