Upper Flannagan Pond Dam

TRIBUTARY OF NONACOCUS BROOK· Middlesex, Massachusetts· Built 1955· Concrete· 9 ft tall
Significant Hazard Recreation Private

Key Takeaway

Upper Flannagan Pond Dam is classified as significant hazard in Massachusetts. It was completed in 1955 and is 71 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 9 ft (taller than 12.4% in MA)
Dam Length77 ft
Dam TypeConcrete
Max Storage110 acre-ft
Normal Storage75 acre-ft
Surface Area23 acres
Drainage Area1 sq mi
Year Completed1955 (71 years old)
NID IDMA00810

Safety Information

Significant Hazard

No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
Last Inspection: May 18, 2012
State Regulated: Yes
Regulatory Agency: DEPARTMENT OF CONSERVATION AND RECREATION

Ownership

LINDA J. & JOHN H. WESLEY

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Upper Flannagan Pond Dam?

Upper Flannagan Pond Dam is classified as Significant Hazard. No probable loss of human life, but can cause economic loss, environmental damage, or disruption of lifeline facilities. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Upper Flannagan Pond Dam?

Upper Flannagan Pond Dam is owned by LINDA J. & JOHN H. WESLEY (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Upper Flannagan Pond Dam built?

Upper Flannagan Pond Dam was completed in 1955, making it 71 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Upper Flannagan Pond Dam?

Upper Flannagan Pond Dam serves the following purposes: Recreation. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Upper Flannagan Pond Dam?

Upper Flannagan Pond Dam has a dam height of 9 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

When was Upper Flannagan Pond Dam last inspected?

Upper Flannagan Pond Dam was last inspected on May 18, 2012. Inspection dates indicate when a formal review occurred, not the results of that inspection.

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.