Helmetta Dam

Manalapan Brook· Middlesex, New Jersey· Earth· 7 ft tall
Significant Hazard Recreation Local Government

Key Takeaway

Helmetta Dam is classified as significant hazard in New Jersey. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 7 ft (taller than 1.9% in NJ)
Dam Length2,000 ft
Dam TypeEarth
Normal Storage64 acre-ft
Surface Area50 acres
Drainage Area2 sq mi
Max Discharge41 cfs
NID IDNJ00794

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: Yes
Last Inspection: August 30, 2021
State Regulated: Yes
Regulatory Agency: NJDEP

Ownership

County of Middlesex, Engineering Department

Local Government

Nearby Dams

Cranbury S. River Basin B1 Dam

Middlesex, NJ

Low Hazard 30 ft

Manalapan Lake Dam

Middlesex, NJ

High Hazard 15 ft

Devoe Lake Dam

Middlesex, NJ

High Hazard 15 ft

Duhernal Dam

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Significant Hazard 13 ft

Regency Monroe Pond Dam

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High Hazard 14 ft

Mill Pond Dam

Middlesex, NJ

Low Hazard 8 ft

Farrington Dam

Middlesex, NJ

High Hazard 34 ft

Davidsons Mill Pond Dam

Middlesex, NJ

Significant Hazard 10 ft

Frequently Asked Questions

What is the hazard classification of Helmetta Dam?

Helmetta 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 Helmetta Dam?

Helmetta Dam is owned by County of Middlesex, Engineering Department (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

What is the primary purpose of Helmetta Dam?

Helmetta 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 Helmetta Dam?

Helmetta Dam has a dam height of 7 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 Helmetta Dam last inspected?

Helmetta Dam was last inspected on August 30, 2021. 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.