Manahawkin Lake Dam

Mill Creek· Ocean, New Jersey· Built 1929· Earth· 12 ft tall
Significant Hazard Recreation Local Government

Key Takeaway

Manahawkin Lake Dam is classified as significant hazard in New Jersey. It was completed in 1929 and is 97 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 12 ft (taller than 31.2% in NJ)
Dam Length900 ft
Dam TypeEarth
Normal Storage127 acre-ft
Surface Area54 acres
Drainage Area20 sq mi
Max Discharge1,908 cfs
Year Completed1929 (97 years old)
NID IDNJ00057

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: September 10, 2021
State Regulated: Yes
Regulatory Agency: NJDEP

Ownership

County of Ocean

Local Government

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Manahawkin Lake Dam?

Manahawkin Lake 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 Manahawkin Lake Dam?

Manahawkin Lake Dam is owned by County of Ocean (Local Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Manahawkin Lake Dam built?

Manahawkin Lake Dam was completed in 1929, making it 97 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 Manahawkin Lake Dam?

Manahawkin Lake 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 Manahawkin Lake Dam?

Manahawkin Lake Dam has a dam height of 12 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 Manahawkin Lake Dam last inspected?

Manahawkin Lake Dam was last inspected on September 10, 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.