Half Moon Pond Reservoir Report

Last Updated: December 20, 2025

Half Moon Pond, located in Waldo, Maine, is a concrete dam primarily used for water supply purposes.


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Summary

With a height of 10 feet and a storage capacity of 880 acre-feet, this structure plays a crucial role in ensuring the availability of water in the area. Despite its relatively low hazard potential, the dam is subject to state regulation, inspection, and enforcement by MEMA, highlighting the importance of maintaining its integrity and functionality.

The dam, situated on the Halfmoon Pond stream, was last inspected in August 1997, with a scheduled inspection frequency of 12 years. While its condition assessment is currently listed as "Not Rated," the structure's emergency action plan (EAP) status and risk assessment details are not available. Nevertheless, Half Moon Pond Dam continues to serve as a vital resource for the region, contributing to the water management efforts in the area.

Managed by a public utility, Half Moon Pond Dam stands as a testament to the collaboration between state and federal agencies in safeguarding water resources. Its modest dimensions of 30 feet in length and 176 acres in surface area belie its significance in the local ecosystem. With its controlled spillway width of 4 feet and strategic location within the New England District, the dam represents a harmonious balance between water supply needs and environmental conservation in the region.

Dam Length

30

Dam Height

10

River Or Stream

Halfmoon Pond

Primary Dam Type

Concrete

Surface Area

176

Hydraulic Height

10

Nid Storage

880

Structural Height

10

Hazard Potential

Low

Nid Height

10
       
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.