Tillson Lake Dam

PALMAGHATT KILL· Ulster, New York· Built 1930· Earth· 39 ft tall

High Hazard Recreation State Government

Key Takeaway

Tillson Lake Dam is classified as high hazard in New York. It was completed in 1930 and is 96 years old. Its primary use is recreation. High hazard means loss of life is likely if the dam fails — it does not indicate the dam's current condition. Learn more.

Physical Details

Dam Height	39 ft (taller than 87.6% in NY)
Dam Length	308 ft
Dam Type	Earth
Max Storage	394 acre-ft
Normal Storage	230 acre-ft

Surface Area	23 acres
Drainage Area	5 sq mi
Max Discharge	2,690 cfs
Year Completed	1930 (96 years old)
NID ID	NY00083

Safety Information

High Hazard

Loss of human life is likely if the dam fails.

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

Emergency Action Plan: Yes

Last Inspection: April 7, 2020

State Regulated: Yes

Regulatory Agency: NYS DEC

Ownership

NYSOPRHP - PALISADES INTERSTATE PARK COMMISSION

State Government

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I Scott Watkins Dam

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Lake Maratanza Dam

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Pecks Dam

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Borden Estate Dam

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Walden

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Frequently Asked Questions

What is the hazard classification of Tillson Lake Dam?

Tillson Lake Dam is classified as High Hazard. Loss of human life is likely if the dam fails. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Tillson Lake Dam?

Tillson Lake Dam is owned by NYSOPRHP - PALISADES INTERSTATE PARK COMMISSION (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Tillson Lake Dam built?

Tillson Lake Dam was completed in 1930, making it 96 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 Tillson Lake Dam?

Tillson 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 Tillson Lake Dam?

Tillson Lake Dam has a dam height of 39 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 Tillson Lake Dam last inspected?

Tillson Lake Dam was last inspected on April 7, 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.