Lancaster Mill Pond Dam Reservoir Report
Last Updated: December 16, 2025
The Lancaster Mill Pond Dam, located on the South Branch of the Nashua River in Clinton, Massachusetts, is a picturesque masonry structure with a primary purpose of recreation.
°F
°F
mph
Wind
%
Humidity
Summary
Standing at a height of 26 feet and a hydraulic height of 21 feet, this dam provides storage of up to 500 acre-feet of water for various recreational activities. With a surface area of 0.05 square miles and a drainage area of 123 square miles, the dam also serves to regulate water flow in the surrounding area.
Managed by a private owner but regulated by the Department of Conservation and Recreation in Massachusetts, the Lancaster Mill Pond Dam has a significant hazard potential due to its age and condition, assessed as fair during its last inspection in 2017. Despite this, the risk assessment for the dam is moderate, with a risk management plan in place to address any potential issues. Overall, this historic dam plays a vital role in both water resource management and climate resilience efforts in the region, making it a significant structure for enthusiasts interested in these fields.
Dam Length |
190 |
Dam Height |
26 |
River Or Stream |
SOUTH BRANCH OF NASHUA RIVER |
Primary Dam Type |
Masonry |
Surface Area |
0.05 |
Hydraulic Height |
21 |
Drainage Area |
123 |
Nid Storage |
500 |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Nid Height |
26 |
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.
Lancaster Mill Pond Dam
Bartlett Street 152, Northborough