Millpond Dam Reservoir Report
Nearby: Ben Smith Dam Assabet
Last Updated: December 18, 2025
Millpond Dam, located in Maynard, Massachusetts, is a privately owned structure primarily used for hydroelectric purposes.
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Summary
Built in 1890, this gravity dam stands at 20 feet tall and spans 85 feet in length, with a storage capacity of 878 acre-feet. It is regulated by the Department of Conservation and Recreation in Massachusetts and undergoes regular inspections to ensure its structural integrity.
With a significant hazard potential and a very high risk assessment rating, Millpond Dam faces potential risks that need to be managed effectively. Despite its satisfactory condition assessment as of September 2017, the dam requires close monitoring and adherence to safety guidelines. As a controlled spillway type dam, it plays a crucial role in managing water resources in the area, providing both environmental and energy benefits.
Situated on a tributary of the Assabet River, Millpond Dam plays a vital role in the region's water management and climate resilience efforts. With its historical significance and ongoing operational importance, this dam serves as a key infrastructure for both local communities and the environment, highlighting the intersection of water resource management and climate adaptation in the area.
Year Completed |
1890 |
Dam Length |
85 |
Dam Height |
20 |
River Or Stream |
TRIBUTARY OF ASSABET RIVER |
Primary Dam Type |
Gravity |
Surface Area |
18.5 |
Hydraulic Height |
6 |
Drainage Area |
115 |
Nid Storage |
878 |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Nid Height |
20 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo 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
HighDams 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.
Millpond Dam
Seymour Street 1A, Concord