Mystic Reservoir Dam is an earth dam located in New London County, Connecticut, built in 1880. It carries a High hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 34 ft34 ft tall and 450 ft long, taller than 78% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Mystic Reservoir Dam
The primary purpose of Mystic Reservoir Dam 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 Aquarion Water Company of Connecticut (public utility). It impounds the Copps Brook near Stonington.
The dam stands 34 feet tall and stretches 450 feet across, creates a reservoir covering 50 acres, has a maximum storage capacity of 350 acre-feet, and collects water from a drainage area of 6 square miles. Completed in 1880, 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 04/19/2024.
At 34 feet, this dam is taller than 78% 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 Connecticut 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 | Connecticut |
| County | New London |
| Nearest City | Stonington |
| River/Stream | Copps Brook |
| Coordinates | 41.36535, -71.93544 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 34 ft |
| Dam Height | 34 ft |
| Dam Length | 450 ft |
| Year Completed | 1880 (146 years old) |
Storage & Hydraulics
| NID Storage | 350 acre-ft |
| Max Storage | 350 acre-ft |
| Normal Storage | 250 acre-ft |
| Surface Area | 50 acres |
| Drainage Area | 6 sq mi |
| Max Discharge | 2,525 cfs |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Aquarion Water Company of Connecticut |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/19/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CT00613 |
| Federal ID | CT00613 |
| More Info | State Dam Safety Program |