Great Swamp Fc Aka Norwalk River #2 Dam Reservoir Report

Last Updated: December 5, 2025

The Great Swamp Fc Aka Norwalk River #2 Dam, located in Ridgefield, Connecticut, is an essential flood control structure designed by the USDA NRCS and completed in 1979.


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Summary

This earth dam, primarily owned by the state, serves the purpose of flood risk reduction along the Ridgefield Brook, with a height of 12 feet and a length of 276 feet. The dam's uncontrolled spillway and outlet gates help manage water levels in the 134-acre surface area and protect the surrounding area from potential flooding events.

Managed by the Connecticut Department of Energy and Environmental Protection (DEEP), the Great Swamp Dam is regularly inspected to ensure its structural integrity and safety. With a high hazard potential but a satisfactory condition assessment as of October 2018, the dam's risk assessment is rated as moderate. Despite its age, the dam continues to effectively reduce flood risks in the area and plays a crucial role in protecting the local community and environment from excessive water flow and potential damage.

As climate change impacts continue to pose challenges to water resources and increase the frequency of extreme weather events, the Great Swamp Fc Aka Norwalk River #2 Dam remains a crucial infrastructure for maintaining flood resilience in Ridgefield. With state regulation, inspection, and enforcement in place, this dam stands as a vital piece of the flood control system in Connecticut, highlighting the importance of effective water resource management and climate adaptation strategies in safeguarding communities against natural disasters.

Year Completed

1979

Dam Length

276

Dam Height

12

River Or Stream

RIDGEFIELD BROOK

Primary Dam Type

Earth

Surface Area

134

Drainage Area

2.6

Outlet Gates

Uncontrolled

Hazard Potential

High

Foundations

Rock, Soil

Nid Height

12
       
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.