Tivoli Lake Spillway

TR-RAMAPO RIVER· Rockland, New York· Built 1908· Concrete· 5 ft tall
Significant Hazard Recreation Water Supply Private

Key Takeaway

Tivoli Lake Spillway is classified as significant hazard in New York. It was completed in 1908 and is 118 years old. Its primary use is recreation. Significant hazard means failure could cause economic or environmental damage. Learn more.

Physical Details

Dam Height 5 ft (taller than 0.1% in NY)
Dam Length205 ft
Dam TypeConcrete
Max Storage1.1K acre-ft
Normal Storage800 acre-ft
Surface Area103 acres
Drainage Area2 sq mi
Year Completed1908 (118 years old)
NID IDNY14640

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: July 28, 2020
State Regulated: Yes
Regulatory Agency: NYS DEC

Ownership

PIERSON LAKE HOMEOWNERS ASSOCIATION

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Tivoli Lake Spillway?

Tivoli Lake Spillway 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 Tivoli Lake Spillway?

Tivoli Lake Spillway is owned by PIERSON LAKE HOMEOWNERS ASSOCIATION (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Tivoli Lake Spillway built?

Tivoli Lake Spillway was completed in 1908, making it 118 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 Tivoli Lake Spillway?

Tivoli Lake Spillway serves the following purposes: Recreation, Water Supply. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Tivoli Lake Spillway?

Tivoli Lake Spillway has a dam height of 5 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 Tivoli Lake Spillway last inspected?

Tivoli Lake Spillway was last inspected on July 28, 2020. 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.