Patch Reservoir Dam Reservoir Report

Last Updated: December 12, 2025

Patch Reservoir Dam, located in Worcester, Massachusetts, was completed in 1896 and serves as a crucial structure for recreational purposes, offering a serene environment for water enthusiasts and nature lovers alike.


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Summary

The dam, primarily owned and regulated by the Department of Conservation and Recreation in Massachusetts, stands at a height of 8.7 feet and has a hydraulic height of 5 feet, providing a storage capacity of 229 acre-feet for the surrounding area. With a surface area of 34 acres and a drainage area of 9.7 square miles, Patch Reservoir Dam plays a key role in managing water resources in the region, particularly in the Tatnuck Brook watershed.

Despite its age, Patch Reservoir Dam is assessed to be in fair condition, with a high hazard potential due to its proximity to residential areas. Regular inspections, conducted every two years, ensure the safety and integrity of the dam, with the latest assessment in October 2019 confirming its overall stability. The dam's spillway type is uncontrolled, reflecting its historical construction and design. While the risk assessment deems the dam as having a moderate risk level, appropriate risk management measures are in place to address any potential issues and ensure the safety of the surrounding community. For water resource and climate enthusiasts, Patch Reservoir Dam stands as a testament to the importance of maintaining and managing infrastructure for both recreational enjoyment and environmental conservation.

Year Completed

1896

Dam Length

65

Dam Height

8.7

River Or Stream

TATNUCK BROOK

Primary Dam Type

Masonry

Surface Area

34

Hydraulic Height

5

Drainage Area

9.7

Nid Storage

229

Hazard Potential

High

Foundations

Unlisted/Unknown

Nid Height

9
       
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.