Nagog Pond Dam
Nagog Pond Dam is an earth dam located in Middlesex County, Massachusetts, built in 1909. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Nagog Pond Dam
The primary purpose of Nagog Pond 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 Concord (local government). It impounds the Nagog Brook near Acton.
The dam stands 15 feet tall and stretches 170 feet across, creates a reservoir covering 285 acres, has a maximum storage capacity of 3,140 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1909, the structure is over a century 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 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 06/09/2023.
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Location
| State | Massachusetts |
| County | Middlesex |
| Nearest City | Acton |
| River/Stream | Nagog Brook |
| Coordinates | 42.50989, -71.43355 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 15 ft |
| Dam Length | 170 ft |
| Year Completed | 1909 (117 years old) |
Storage & Hydraulics
| NID Storage | 3,140 acre-ft |
| Max Storage | 3,140 acre-ft |
| Normal Storage | 2,698 acre-ft |
| Surface Area | 285 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 90 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Town of Concord |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 06/09/2023 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MA00129 |
| Federal ID | MA00129 |
| More Info | State Dam Safety Program |