Greenwood Lake Dam Reservoir Report
Nearby: Sweets Pond Dam Robinson Pond Dam
Last Updated: December 13, 2025
Greenwood Lake Dam, located in North Attleboro, Massachusetts, is a Federal-owned structure managed by the Fish and Wildlife Service for the primary purpose of maintaining a Fish and Wildlife Pond.
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Summary
Built in 1854, this Rockfill dam stands at a height of 18 feet and spans 600 feet in length, with a storage capacity of 626 acre-feet and a surface area of 128 acres. Despite its age, the dam is in satisfactory condition according to the last inspection conducted in September 2015.
The dam's controlled spillway, with a width of 96 feet, helps regulate water discharge, ensuring the safety of downstream areas along the Bungay River. With a hazard potential rated as high and a risk assessment indicating a very high risk level, the dam requires ongoing monitoring and maintenance to mitigate potential risks. While the dam has not been modified since 1996, it is subject to regular inspections every three years to assess its structural integrity and overall condition. In case of emergencies, the dam lacks an Emergency Action Plan preparedness, highlighting the importance of establishing comprehensive risk management measures.
As a significant component of the local water resource infrastructure, Greenwood Lake Dam serves not only as a habitat for fish and wildlife but also as a recreational area for the community. With its historical significance and critical role in water management, the dam underscores the importance of balancing conservation efforts with public safety and environmental stewardship in the face of evolving climate challenges.
Years Modified |
1996 - Hydraulic |
Year Completed |
1854 |
Dam Length |
600 |
Dam Height |
12 |
River Or Stream |
Bungay River |
Primary Dam Type |
Rockfill |
Surface Area |
128 |
Hydraulic Height |
12 |
Drainage Area |
1.4 |
Nid Storage |
626 |
Structural Height |
18 |
Outlet Gates |
Other Controlled, Slide (sluice gate), Vertical Lift |
Hazard Potential |
High |
Foundations |
Soil |
Nid Height |
18 |
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.
Greenwood Lake Dam
Falls Pond