Tanglewood Lake Dam Reservoir Report

Last Updated: December 6, 2025

Tanglewood Lake Dam, located in Delancey, New York, stands as a private-owned structure regulated by the New York State Department of Environmental Conservation.


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Summary

Built in 1980, this earthen dam serves primarily for recreational purposes, with a storage capacity of 50.4 acre-feet and a surface area of 10 acres. The dam overlooks the picturesque BULLET HOLE BROOK, providing a serene backdrop for outdoor enthusiasts to enjoy.

Despite its scenic setting, Tanglewood Lake Dam poses a significant hazard potential with a poor condition assessment as of January 2018. The dam's spillway, which is uncontrolled, has a width of 20 feet. The last inspection conducted in January 2020 revealed the need for improvement, highlighting the importance of regular maintenance and risk management measures to ensure the safety of the surrounding community and the dam's structural integrity.

With a moderate risk assessment score of 3, Tanglewood Lake Dam requires attention to address its current condition and potential hazards. As the dam is essential for recreational activities and serves as a local landmark, ongoing monitoring, maintenance, and possibly rehabilitation efforts are crucial to safeguard both the dam and the environment it influences. Climate and water resource enthusiasts would find Tanglewood Lake Dam an intriguing case study in the intersection of human-made infrastructure and natural ecosystems.

Year Completed

1980

Dam Length

105

River Or Stream

BULLET HOLE BROOK

Primary Dam Type

Earth

Surface Area

10

Drainage Area

2.08

Nid Storage

50.4

Hazard Potential

Significant
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.

Hazard Potential Classification

High
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.