Dayville Wasteway Reservoir Report

Last Updated: December 5, 2025

Dayville Wasteway, located in Dayville, Connecticut, is a historic stone dam built in 1925 for hydroelectric purposes on the Five Mile River.


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Summary

The dam has a height of 14 feet and a length of 26 feet, with a storage capacity of 93 acre-feet and a drainage area of 57 square miles. With a maximum discharge of 2640 cubic feet per second, the dam is classified as having a low hazard potential and moderate risk assessment.

Managed by a private owner and regulated by the Federal Energy Regulatory Commission, Dayville Wasteway serves as an essential structure for water resource management and climate resilience in the region. Although the dam has not been inspected since July 2019, it is considered to be in good condition overall, with no available assessment data. The dam features an uncontrolled spillway and has associated structures CT00169S001 and CT00169S002.

For enthusiasts interested in water resources and climate, Dayville Wasteway presents a fascinating example of early 20th-century hydroelectric infrastructure in New England. With its historical significance and continued operational importance, this dam showcases the intersection of human engineering with natural water systems, highlighting the ongoing relevance of sustainable water management practices in the face of changing environmental conditions.

Year Completed

1925

Dam Length

26

Dam Height

14

River Or Stream

Five Mile River

Primary Dam Type

Stone

Surface Area

31

Drainage Area

57

Nid Storage

93

Hazard Potential

Low

Nid Height

14
       
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.