Long Hill Reservoir Dam
Long Hill Reservoir Dam is an earth dam located in New Haven County, Connecticut, built in 1914. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Long Hill Reservoir Dam
The primary purpose of Long Hill 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 Connecticut Water Company (public utility). It impounds the Beacon Hill Brook near Woodbridge.
The dam stands 80 feet tall and stretches 890 feet across, creates a reservoir covering 87 acres, has a maximum storage capacity of 2,140 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1914, 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 12/12/2024.
At 80 feet, this dam is taller than 97% 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 | New Haven |
| Nearest City | Woodbridge |
| River/Stream | Beacon Hill Brook |
| Coordinates | 41.46620, -72.98669 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 80 ft |
| Dam Height | 80 ft |
| Dam Length | 890 ft |
| Year Completed | 1914 (112 years old) |
Storage & Hydraulics
| NID Storage | 2,148 acre-ft |
| Max Storage | 2,140 acre-ft |
| Normal Storage | 2,148 acre-ft |
| Surface Area | 87 acres |
| Drainage Area | 2 sq mi |
| Max Discharge | 2,130 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Connecticut Water Company |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 12/12/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CT00307 |
| Federal ID | CT00307 |
| More Info | State Dam Safety Program |