Johns Pond Dam Reservoir Report

Last Updated: December 5, 2025

Johns Pond Dam, located in Ridgefield, Connecticut, is a private dam with a primary purpose of recreation.


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Summary

Situated on Cooper Pond Brook, this earth dam stands at a height of 8 feet and has a length of 150 feet. With a storage capacity of 10.67 acre-feet and a maximum discharge of 487 cubic feet per second, this dam provides essential water resource management for the surrounding area.

Despite its recreational focus, Johns Pond Dam poses a significant hazard potential, although its condition assessment is currently not rated. The last inspection of the dam was conducted in April 1987, with an inspection frequency of 5 years. While the dam has state regulation and enforcement in place, there is no Emergency Action Plan (EAP) prepared, and the risk assessment and management measures are not specified.

Climate and water enthusiasts will find Johns Pond Dam an intriguing structure for its role in providing recreational opportunities while also managing water resources in the Fairfield County area. The dam's location, design, and storage capacity make it a key feature in the region's water infrastructure, highlighting the intersection of human activity and environmental stewardship in the face of changing climate patterns.

Dam Length

150

Dam Height

8

River Or Stream

COOPER POND BROOK

Primary Dam Type

Earth

Surface Area

6

Drainage Area

0.91

Nid Storage

10.67

Hazard Potential

Significant

Nid Height

8
       
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.