Danielson Mill Dam Reservoir Report
Nearby: Kingsbury Pond Dam Turner Pond Dam
Last Updated: December 18, 2025
Located in Medfield, Massachusetts, the Danielson Mill Dam is a significant earth dam on the West Branch of the Nantasket River, primarily serving recreational purposes.
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Summary
Managed by the local government, the dam is regulated by the Department of Conservation and Recreation, with state permitting, inspection, and enforcement in place to ensure its safety and compliance with regulations. With a height of 7 feet and a hydraulic height of 6 feet, the dam boasts a storage capacity of 32.6 acre-feet and a surface area of 6.4 acres.
Despite its importance for recreation, the Danielson Mill Dam is classified as having a significant hazard potential and a poor condition assessment, last assessed in October 2017. The dam lacks an emergency action plan and has not been updated in recent years, raising concerns about its ability to respond effectively in case of emergencies. However, with a moderate risk assessment rating of 3, there is room for improvement through the implementation of risk management measures and regular monitoring of its condition.
Water resource and climate enthusiasts interested in the Danielson Mill Dam will find a unique opportunity to study the intersection of recreational infrastructure and environmental conservation. The dam's location in Norfolk County, Massachusetts, offers a valuable case study for understanding the challenges and opportunities associated with managing dams in urban areas, emphasizing the importance of proactive maintenance and risk mitigation strategies to ensure the safety and sustainability of water resources in the region.
Dam Length |
1300 |
Dam Height |
7 |
River Or Stream |
WEST BRANCH OF NANTASKET RIVER |
Primary Dam Type |
Earth |
Surface Area |
6.4 |
Hydraulic Height |
6 |
Drainage Area |
0.41 |
Nid Storage |
32.6 |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Nid Height |
7 |
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.
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