Still Lake Dam Reservoir Report

Last Updated: December 21, 2025

Still Lake Dam, located in Briarcliff Manor, New York, is a privately owned structure that serves primarily for recreational purposes.


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Summary

The dam, completed in 1930, stands at a height of 16 feet and spans 540 feet in length, with a storage capacity of 177 acre-feet. Situated on the TR-New Croton Reservoir river, the dam is regulated by the New York State Department of Environmental Conservation (NYS DEC) and undergoes regular inspections to ensure its safety and compliance with state regulations.

Despite its recreational significance, Still Lake Dam poses a high hazard potential due to its poor condition assessment as of September 2018. The dam features an uncontrolled spillway, with a width of 4 feet, and has a maximum discharge capacity of 30 cubic feet per second. With a drainage area of 0.22 square miles, the dam's surface area covers 24 acres. The risk assessment for the dam is classified as moderate, with a risk management plan in place to address potential safety concerns.

Given its historical significance and importance for recreation in the area, efforts are underway to address the dam's condition and ensure its long-term sustainability. With its proximity to the New Croton Reservoir and the surrounding Westchester County, Still Lake Dam remains a focal point for water resource and climate enthusiasts who are invested in the preservation and management of this vital infrastructure.

Year Completed

1930

Dam Length

540

Dam Height

16

River Or Stream

TR-NEW CROTON RESERVOIR

Primary Dam Type

Masonry

Surface Area

24

Drainage Area

0.22

Nid Storage

177

Hazard Potential

High

Nid Height

16
       
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.