Hopkinton State Park Swimming Pool Dam Reservoir Report

Last Updated: December 15, 2025

Hopkinton State Park Swimming Pool Dam is a state-regulated structure located in Ashland, Massachusetts.


°F

°F

mph

Wind

%

Humidity

Summary

Built in 1967, this Earth dam serves primarily as a Fish and Wildlife Pond, with additional recreational purposes. Standing at a height of 16.5 feet with a hydraulic height of 9.5 feet, the dam holds a normal storage capacity of 71 acre-feet and has a drainage area of 0.07 square miles. Despite its high hazard potential, the dam is deemed to be in satisfactory condition as of the last inspection in June 2016.

The dam's spillway type is labeled as "Uncontrolled", with a length of 500 feet and a surface area of 15 acres. The structure is associated with the tributary to Indian Brook and falls under the jurisdiction of the Department of Conservation and Recreation in Massachusetts. The risk assessment for the dam is classified as moderate, with a risk score of 3 out of a possible range. While the dam has undergone regular inspections and meets state regulatory requirements, it is important for water resource and climate enthusiasts to stay informed about any updates or changes in its condition to ensure the safety and integrity of the surrounding area.

Year Completed

1967

Dam Length

500

Dam Height

16.5

River Or Stream

TRIBUTARY TO INDIAN BROOK

Primary Dam Type

Earth

Surface Area

15

Hydraulic Height

9.5

Drainage Area

0.07

Nid Storage

146

Hazard Potential

High

Foundations

Unlisted/Unknown

Nid Height

17
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No 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

High
Dams 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.