Jones Pond Dam Reservoir Report

Last Updated: December 14, 2025

Jones Pond Dam, also known as Ellis Hatch Dam, is a state-owned structure located in Middleton, New Hampshire.


°F

°F

mph

Wind

%

Humidity

Summary

Completed in 1981, this earth dam serves primarily for recreational purposes and is regulated by the NHDES Dam Bureau. With a height of 19 feet and a length of 567 feet, the dam has a storage capacity of 245 acre-feet and a surface area of 19 acres.

Despite its satisfactory condition assessment, Jones Pond Dam is classified as having a high hazard potential due to its location on Jones Brook. The dam's spillway type is uncontrolled with a width of 3 feet, and it is subject to regular inspections every two years. In the event of an emergency, the dam's emergency action plan (EAP) was last revised in 2014, but its compliance with guidelines and the preparedness of inundation maps are unclear.

Overall, Jones Pond Dam presents a moderate risk (3) in terms of potential hazards and risk management measures. For water resource and climate enthusiasts, this dam serves as a vital structure for recreational activities while highlighting the importance of proper regulation, inspection, and emergency preparedness in safeguarding water resources and mitigating risks associated with dam infrastructure.

Year Completed

1981

Dam Length

567

Dam Height

19

River Or Stream

JONES BROOK

Primary Dam Type

Earth

Surface Area

19

Drainage Area

0.42

Nid Storage

245

Hazard Potential

High

Foundations

Unlisted/Unknown

Nid Height

19
       
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.