Sphagnum Pond Dam Reservoir Report

Last Updated: December 6, 2025

Sphagnum Pond Dam, located in Cornwall, New York, is a masonry dam completed in 1930 for the primary purpose of water supply.


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Summary

With a height of 15 feet and a length of 580 feet, the dam has a storage capacity of 102 acre-feet, with a normal storage level of 95 acre-feet and a surface area of 20 acres. The dam is regulated by the New York State Department of Environmental Conservation and undergoes regular inspections, with the last assessment in 2017 revealing a poor condition and significant hazard potential.

Despite its age, Sphagnum Pond Dam continues to serve as a critical water resource for the local community. However, its poor condition and the moderate risk assessment highlight the need for ongoing risk management measures to ensure the safety and reliability of the structure. With an uncontrolled spillway and a significant hazard potential, there is a pressing need for maintenance and potentially upgrades to enhance the dam's resilience to climate change impacts and ensure its continued functionality as a key water supply infrastructure in the region.

As a focal point for water resource and climate enthusiasts, Sphagnum Pond Dam presents a unique case study in the intersection of infrastructure management, environmental regulation, and climate resilience. The dam's location along the TR-Hudson River, its significant hazard potential, and poor condition assessment underscore the importance of proactive risk management and investment in sustainable water infrastructure to mitigate the potential impacts of extreme weather events and changing hydrological patterns in the future.

Year Completed

1930

Dam Length

580

Dam Height

15

River Or Stream

TR-HUDSON RIVER

Primary Dam Type

Masonry

Surface Area

20

Nid Storage

102

Hazard Potential

Significant

Nid Height

15
       
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.