Pearley Terrill Dam Reservoir Report

Last Updated: December 16, 2025

Pearley Terrill Dam, located in Pittsburg, New Hampshire, is a state-regulated structure on the West Branch Indian Stream.


°F

°F

mph

Wind

%

Humidity

Summary

Completed in 1969, this earth dam stands at 14 feet tall and stretches 330 feet in length, primarily serving the purpose of recreation. With a normal storage capacity of 277 acre-feet and a maximum capacity of 336 acre-feet, the dam covers a surface area of 60 acres and drains an area of 4.65 square miles.

Despite being classified as having low hazard potential, the condition assessment of Pearley Terrill Dam is rated as fair. The last inspection in October 2016 revealed its moderate risk level, prompting a six-year inspection frequency. While the dam has not experienced any major modifications in recent years, its emergency action plan (EAP) status, inundation maps, and risk management measures remain unspecified. With its location in the Coos County of New Hampshire, this dam is under the regulatory oversight of the NHDES Dam Bureau, ensuring its adherence to state permitting, inspection, and enforcement protocols. For water resource and climate enthusiasts, Pearley Terrill Dam provides an intriguing case study in dam management and risk assessment within the beautiful landscapes of northern New Hampshire.

Year Completed

1969

Dam Length

330

Dam Height

14

River Or Stream

WEST BRANCH INDIAN STREAM

Primary Dam Type

Earth

Surface Area

60

Drainage Area

4.65

Nid Storage

336

Hazard Potential

Low

Foundations

Unlisted/Unknown

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.