Great Stone
Great Stone is a masonry dam located in Essex County, Massachusetts, built in 1848. It carries a Low hazard potential classification and has a satisfactory condition assessment.
About Great Stone
The primary purpose of Great Stone is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Lawrence Hydroelectric Associates (private). It impounds the Merrimack River near Lawrence.
The dam stands 38 feet tall and stretches 943 feet across, creates a reservoir covering 655 acres, has a maximum storage capacity of 19,900 acre-feet, and collects water from a drainage area of 4,660 square miles. Completed in 1848, the structure is one of the older dams in the region, with over a century and a half of service.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 06/15/2022.
At 38 feet, this dam is taller than 85% of dams nationwide.
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Location
| State | Massachusetts |
| County | Essex |
| Nearest City | Lawrence |
| River/Stream | Merrimack River |
| Coordinates | 42.70060, -71.16650 |
Physical Characteristics
| Dam Type | Masonry |
| NID Height | 38 ft |
| Dam Height | 38 ft |
| Dam Length | 943 ft |
| Year Completed | 1848 (178 years old) |
Storage & Hydraulics
| NID Storage | 19,900 acre-ft |
| Max Storage | 19,900 acre-ft |
| Normal Storage | 19,900 acre-ft |
| Surface Area | 655 acres |
| Drainage Area | 4,660 sq mi |
| Max Discharge | 128,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Lawrence Hydroelectric Associates |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Satisfactory |
| Last Inspection | 06/15/2022 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | MA00234 |
| Federal ID | MA00234 |
| More Info | State Dam Safety Program |