Lake Uncas Dam

TR-SPRAGUE BROOK· Sullivan, New York· Built 1940· Earth· 12 ft tall
Low Hazard Recreation Private

Key Takeaway

Lake Uncas Dam is classified as low hazard in New York. It was completed in 1940 and is 86 years old. Its primary use is recreation.

Physical Details

Dam Height 12 ft (taller than 23.2% in NY)
Dam Length240 ft
Dam TypeEarth
Max Storage184 acre-ft
Normal Storage120 acre-ft
Surface Area32 acres
Max Discharge55 cfs
Year Completed1940 (86 years old)
NID IDNY01209

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

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

Emergency Action Plan: No
Last Inspection: June 12, 2009
State Regulated: Yes
Regulatory Agency: NYS DEC

Ownership

MONASTERY OUR LADY OF BEATITUDE

Private

Nearby Dams

Orchard Lake Dam

Sullivan, NY

Significant Hazard 16 ft

Knickerbocker Pond Dam

Sullivan, NY

Low Hazard 10 ft

Mud Pond Dam

Sullivan, NY

Low Hazard 15 ft

Trojan Lake Dam

Sullivan, NY

Low Hazard 16 ft

Waneta Lake Dam

Sullivan, NY

Low Hazard 14 ft

Edgewood Lake Lower Dam

Sullivan, NY

Significant Hazard 15 ft

Edgewood Lake Upper Dam

Sullivan, NY

Significant Hazard 19 ft

Nimrod Lake Dam

Sullivan, NY

Significant Hazard 12 ft

Frequently Asked Questions

What is the hazard classification of Lake Uncas Dam?

Lake Uncas Dam is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Lake Uncas Dam?

Lake Uncas Dam is owned by MONASTERY OUR LADY OF BEATITUDE (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Lake Uncas Dam built?

Lake Uncas Dam was completed in 1940, making it 86 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 Lake Uncas Dam?

Lake Uncas 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 Lake Uncas Dam?

Lake Uncas 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 Lake Uncas Dam last inspected?

Lake Uncas Dam was last inspected on June 12, 2009. 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.