Northfield Mt. - Main Dam

Connecticut River· Franklin, Massachusetts· Built 1973· Rockfill· 145 ft tall
High Hazard Hydroelectric Recreation Public Utility

Physical Details

Dam Height 145 ft (taller than 99.5% in MA)
Dam Length5,500 ft
Dam TypeRockfill
Max Storage21.5K acre-ft
Normal Storage17.1K acre-ft
Surface Area278 acres
Drainage Area1 sq mi
Max Discharge0 cfs
Year Completed1973 (53 years old)
NID IDMA00974

Safety Information

High Hazard

Loss of human life is likely if the dam fails

Emergency Action Plan: Yes
Last Inspection: August 4, 2022
State Regulated: No

Ownership

FirstLight Power Services LLC

Public Utility

Nearby Dams

Ruggles Pond Dam

Franklin, MA

Significant Hazard 9 ft

Bowen's Pond Dam

Franklin, MA

Low Hazard 8 ft

Laurel Lake Dam

Franklin, MA

Low Hazard 9 ft

Stevens Swamp Dam

Franklin, MA

Low Hazard 15 ft

Stillwater Dam

Franklin, MA

Significant Hazard 17 ft

Nelson Mills Pond Dam

Franklin, MA

Significant Hazard 27 ft

Fiske Pond Dam

Franklin, MA

Low Hazard 10 ft

Mcavoy Pond Dam

Franklin, MA

Significant Hazard 12 ft

Frequently Asked Questions

What is the hazard classification of Northfield Mt. - Main Dam?

Northfield Mt. - Main Dam is classified as High Hazard. Loss of human life is likely if the dam fails.

Who owns Northfield Mt. - Main Dam?

Northfield Mt. - Main Dam is owned by FirstLight Power Services LLC (Public Utility).

When was Northfield Mt. - Main Dam last inspected?

Northfield Mt. - Main Dam was last inspected on August 4, 2022.

When was Northfield Mt. - Main Dam built?

Northfield Mt. - Main Dam was completed in 1973, making it 53 years old.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.