Northfield Brook Dam is a gravity dam located in Litchfield County, Connecticut, built in 1965. It carries a High hazard potential classification.
Dam profile
NID height · 111 ft111 ft tall and 810 ft long, taller than 98% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic concrete gravity section and the water level is illustrative.
About Northfield Brook Dam
The primary purpose of Northfield Brook Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by USACE - New England District (federal). It impounds the Northfield Brook near Thomaston.
The dam stands 111 feet tall and stretches 810 feet across, creates a reservoir covering 7 acres, has a maximum storage capacity of 3,200 acre-feet, and collects water from a drainage area of 6 square miles. Completed in 1965, the structure is well into its service life at over 50 years 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. An emergency action plan is in place for this dam. The most recent inspection on record was 01/06/2021.
At 111 feet, this dam is taller than 98% of all dams in the United States.
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 | Litchfield |
| Nearest City | Thomaston |
| River/Stream | Northfield Brook |
| Coordinates | 41.68160, -73.09046 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 111 ft |
| Dam Height | 111 ft |
| Dam Length | 810 ft |
| Year Completed | 1965 (61 years old) |
Storage & Hydraulics
| NID Storage | 3,200 acre-ft |
| Max Storage | 3,200 acre-ft |
| Normal Storage | 80 acre-ft |
| Surface Area | 7 acres |
| Drainage Area | 6 sq mi |
| Max Discharge | 8,800 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | USACE - New England District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not assessed |
| Last Inspection | 01/06/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CT00505 |
| Federal ID | CT00505 |
| More Info | State Dam Safety Program |