Hatfields Reservoir Report

Last Updated: December 18, 2025

Hatfields is a hydroelectric dam located on the Cocheco River in Rochester, New Hampshire.


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Summary

Built in 1937, this concrete gravity dam stands at 20 feet high and has a length of 106 feet, with a storage capacity of 6 acre-feet. The dam is owned by the local government and falls under the jurisdiction of the Federal Energy Regulatory Commission (FERC).

With a significant hazard potential and a moderate risk assessment rating, Hatfields is a key player in the region's water resource management. The dam has a maximum discharge capacity of 7397 cubic feet per second and an uncontrolled spillway width of 87 feet. Despite its age, the dam has not been modified in recent years and its condition assessment is not currently available.

For water resource and climate enthusiasts, Hatfields presents an intriguing case study in the management and regulation of hydroelectric structures. Its historical significance, location on the Cocheco River, and role in providing renewable energy make it a focal point for those interested in sustainable water resource development. With its unique design and operational characteristics, Hatfields offers a glimpse into the intersection of engineering, environmental conservation, and regulatory oversight in the realm of hydroelectric infrastructure.

Year Completed

1937

Dam Length

106

Dam Height

20

River Or Stream

Cocheco River

Primary Dam Type

Concrete

Surface Area

1

Drainage Area

64

Nid Storage

6

Hazard Potential

Significant

Nid Height

20
       
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.