Diamond Mill Pond Dam

Rahway River· Essex, New Jersey· Built 1937· Earth· 9 ft tall
Significant Hazard Recreation Local Government

Key Takeaway

Diamond Mill Pond Dam is classified as significant hazard in New Jersey. It was completed in 1937 and is 89 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 12.9% in NJ)
Dam Length375 ft
Dam TypeEarth
Max Storage24 acre-ft
Normal Storage11 acre-ft
Surface Area4 acres
Drainage Area7 sq mi
Max Discharge1,940 cfs
Year Completed1937 (89 years old)
NID IDNJ00926

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: April 8, 2021
State Regulated: Yes
Regulatory Agency: NJDEP

Ownership

County of Essex Department of Public Works

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Diamond Mill Pond Dam?

Diamond Mill 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 Diamond Mill Pond Dam?

Diamond Mill Pond Dam is owned by County of Essex Department of Public Works (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Diamond Mill Pond Dam built?

Diamond Mill Pond Dam was completed in 1937, making it 89 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 Diamond Mill Pond Dam?

Diamond Mill 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 Diamond Mill Pond Dam?

Diamond Mill 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 Diamond Mill Pond Dam last inspected?

Diamond Mill Pond Dam was last inspected on April 8, 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.