Royal Mills Reservoir Report

Last Updated: December 6, 2025

Royal Mills, also known as Riverpoint Upper Dam, is a historic hydroelectric facility located in West Warwick, Rhode Island.


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Summary

Constructed in 1861, this gravity dam stands at a height of 21 feet and spans 130 feet across the South Branch Pawtuxet River. With a storage capacity of 15.2 acre-feet and a drainage area of 73 square miles, the dam plays a crucial role in generating hydroelectric power in the region.

Managed by a private owner, Royal Mills is regulated by the Federal Energy Regulatory Commission and undergoes regular inspections to ensure its structural integrity and safety. Despite being classified as a high hazard potential structure, the dam's condition assessment is currently not available. As a key player in Rhode Island's water resource management and climate resilience efforts, Royal Mills serves as a reminder of the intersection between historical infrastructure and modern-day environmental stewardship.

With its rich history, picturesque setting, and ongoing role in hydroelectric power production, Royal Mills stands as a testament to the importance of balancing preservation with innovation in the realm of water resources and climate adaptation. As enthusiasts and stakeholders continue to monitor and engage with this iconic structure, its legacy as a vital piece of Rhode Island's energy landscape remains as strong as ever.

Year Completed

1861

Dam Length

130

Dam Height

21

River Or Stream

South Branch Pawtuxet River

Primary Dam Type

Gravity

Surface Area

3.8

Drainage Area

73

Nid Storage

15.2

Hazard Potential

High

Nid Height

21
       
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.