First Herring Brook Reservoir Dam
First Herring Brook Reservoir Dam is an earth dam located in Plymouth County, Massachusetts, built in 1969. It carries a High hazard potential classification and has a satisfactory condition assessment.
About First Herring Brook Reservoir Dam
The primary purpose of First Herring Brook 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 Town Of Scituate (local government). It impounds the First Herring Brook near Scituate.
The dam stands 22 feet tall and stretches 700 feet across, creates a reservoir covering 80 acres, has a maximum storage capacity of 1,150 acre-feet, and collects water from a drainage area of 4 square miles. Completed in 1969, 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. 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 12/16/2022.
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 Massachusetts 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 | Massachusetts |
| County | Plymouth |
| Nearest City | Scituate |
| River/Stream | First Herring Brook |
| Coordinates | 42.18694, -70.75373 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 22 ft |
| Dam Length | 700 ft |
| Year Completed | 1969 (57 years old) |
Storage & Hydraulics
| NID Storage | 1,150 acre-ft |
| Max Storage | 1,150 acre-ft |
| Normal Storage | 500 acre-ft |
| Surface Area | 80 acres |
| Drainage Area | 4 sq mi |
| Max Discharge | 2,300 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Town of Scituate |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 12/16/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00478 |
| Federal ID | MA00478 |
| More Info | State Dam Safety Program |