Townsend Harbor Dam Reservoir Report
Nearby: Bixby Reservoir Dam Heald Pond Dam
Last Updated: December 16, 2025
The Townsend Harbor Dam, located on the Squannacook River in Townsend, Massachusetts, was completed in 1870 and serves primarily for recreation and water supply purposes.
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Summary
The dam, with a height of 11 feet and a hydraulic height of 7.5 feet, has a significant hazard potential but is currently in satisfactory condition according to a 2016 assessment. The dam has a storage capacity of 273 acre-feet and a normal storage level of 116 acre-feet, covering a surface area of 0.06 square miles with a drainage area of 60.6 square miles.
Managed by a private entity, the Townsend Harbor Dam is regulated by the Department of Conservation and Recreation in Massachusetts. It is a rockfill dam type with a gravity and buttress structure, providing critical water supply and recreational opportunities in the area. The dam's spillway is of the uncontrolled type, with a width of 0 feet, and it has no associated locks or outlet gates. The risk assessment for the dam is moderate, and inspections are conducted every 5 years to ensure its safety and compliance with regulations.
Water resource and climate enthusiasts will appreciate the historical significance and functional importance of the Townsend Harbor Dam in managing water resources and providing recreational activities along the Squannacook River. With its long history dating back to the 19th century, the dam continues to play a crucial role in supporting local communities and maintaining the ecological balance of the region. Its presence underscores the delicate balance between water management, environmental conservation, and recreational enjoyment in the face of changing climate patterns and increasing water demands.
Year Completed |
1870 |
Dam Length |
250 |
Dam Height |
11 |
River Or Stream |
SQUANNACOOK RIVER |
Primary Dam Type |
Rockfill |
Surface Area |
0.06 |
Hydraulic Height |
7.5 |
Drainage Area |
60.6 |
Nid Storage |
273 |
Hazard Potential |
Significant |
Foundations |
Unlisted/Unknown |
Nid Height |
11 |
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.
Area Campgrounds
| Location | Reservations | Toilets |
|---|---|---|
Pearl Hill Campground
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Damon Pond Campground
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Grotonwood
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Townsend Harbor Dam
Whalom Lake Public Boat Ramp