Flat River Reservoir Reservoir Report

Last Updated: December 5, 2025

Flat River Reservoir, also known as Johnson's Pond, is a private water resource located in Coventry, Rhode Island.


°F

°F

mph

Wind

%

Humidity

Summary

This gravity dam, completed in 1873, serves primarily for recreational purposes with a storage capacity of 12,650 acre-feet and a surface area of 950 acres. The reservoir is situated along the Pawtuxet River-South Branch, attracting water resource and climate enthusiasts with its picturesque surroundings and opportunities for outdoor activities.

With a height of 20 feet and a hydraulic height of 9 feet, the dam at Flat River Reservoir poses a high hazard potential but is currently assessed to be in fair condition. The last inspection in October 2017 showed that the dam meets regulatory standards, with inspection frequency set at every two years. Despite the potential risks, the reservoir continues to be a popular destination for recreation, offering boating, fishing, and other water-based activities to visitors in Kent County, Rhode Island.

As a significant feature in the region, Flat River Reservoir is regulated by the state and is subject to regular inspections, ensuring the safety and integrity of the dam structure. Water enthusiasts can enjoy the beauty of the reservoir while also being reassured of the responsible management and maintenance practices in place. This blend of natural beauty and regulatory oversight makes Flat River Reservoir a unique and valuable resource for both the local community and those interested in water resource and climate conservation.

Year Completed

1873

Dam Length

750

Dam Height

20

River Or Stream

PAWTUXET RIVER-SOUTH BRANCH

Primary Dam Type

Gravity

Surface Area

950

Hydraulic Height

9

Drainage Area

58

Nid Storage

12650

Structural Height

24

Hazard Potential

High

Nid Height

24
       
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.