Butterworth Lake Dam is an earth dam located in New Haven County, Connecticut, built in 1961. It carries a Significant hazard potential classification and has a fair condition assessment.
Dam profile
NID height · 15 ft15 ft tall and 215 ft long. 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 Butterworth Lake Dam
The primary purpose of Butterworth Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Connecticut Deep (state). It impounds the Butterworth Brook near Hamden.
The dam stands 15 feet tall and stretches 215 feet across, creates a reservoir covering 10 acres, has a maximum storage capacity of 113 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1961, the structure is well into its service life at over 50 years old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. 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 11/03/2021.
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Location
| State | Connecticut |
| County | New Haven |
| Nearest City | Hamden |
| River/Stream | Butterworth Brook |
| Coordinates | 41.43766, -72.89993 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 15 ft |
| Dam Height | 15 ft |
| Dam Length | 215 ft |
| Year Completed | 1961 (65 years old) |
Storage & Hydraulics
| NID Storage | 113 acre-ft |
| Max Storage | 113 acre-ft |
| Normal Storage | 33 acre-ft |
| Surface Area | 10 acres |
| Drainage Area | 2 sq mi |
| Max Discharge | 1,635 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | Connecticut Deep |
| Owner Type | State |
| Hazard Classification | Significant |
| Condition Assessment | Fair |
| Last Inspection | 11/03/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CT00122 |
| Federal ID | CT00122 |
| More Info | State Dam Safety Program |