Conway Treatment Lagoon Dam Reservoir Report

Last Updated: December 16, 2025

Conway Treatment Lagoon Dam, located in Conway, New Hampshire, is a local government-owned structure that serves a critical purpose in water resource management.


°F

°F

mph

Wind

%

Humidity

Summary

Built in 1989, this Earth-type dam stands at a height of 6.5 feet and has a storage capacity of 12.3 acre-feet. Despite its relatively small size, the dam plays a significant role in flood control and water storage for the surrounding area.

Managed by the NHDES Dam Bureau, Conway Treatment Lagoon Dam has been deemed to have a significant hazard potential with a fair condition assessment as of 2015. The dam lacks a spillway and is inspected every four years to ensure its structural integrity and safety. With its high risk assessment rating, it is crucial for the local authorities to implement proper risk management measures to mitigate any potential threats and ensure the dam's continued functionality for the community.

For water resource and climate enthusiasts, Conway Treatment Lagoon Dam serves as a noteworthy example of the importance of proper infrastructure in sustainable water management. As climate change continues to pose challenges to water resources, structures like this dam play a vital role in safeguarding communities against flooding and ensuring a reliable water supply. It highlights the ongoing efforts and responsibilities of regulatory agencies and local governments in maintaining and monitoring critical infrastructure to adapt to changing environmental conditions.

Year Completed

1989

Dam Length

1094

Dam Height

6.5

River Or Stream

NA

Primary Dam Type

Earth

Surface Area

1.31

Nid Storage

12.3

Hazard Potential

Significant

Foundations

Unlisted/Unknown

Nid Height

7
       
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.