Jamestown Lower Reservoir Reservoir Report
Nearby: Jamestown Reservoir Carr Pond
Last Updated: December 25, 2025
Jamestown Lower Reservoir, also known as South or Watson Reservoir, is a local government-owned water supply structure located in Jamestown, Rhode Island.
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Summary
Managed by the state regulatory agencies DS and CRMC, this dam serves the primary purpose of providing water supply to the surrounding area. With a dam height of 12 feet and a storage capacity of 24 acre-feet, the reservoir covers a surface area of 6 acres and has a drainage area of 2 square miles along Jamestown Brook.
Despite being rated as having a significant hazard potential, the condition assessment of Jamestown Lower Reservoir is currently marked as "Not Rated" as of the last inspection in 2012. The dam, primarily constructed with earth material, has a hydraulic height of 7 feet and a structural height of 12 feet. With a maximum discharge capacity of 225 cfs and a spillway width of 8 feet, the reservoir plays a crucial role in maintaining the water supply for the local community. Although lacking recent data on completion year and risk management measures, the reservoir continues to be a focal point for water resource and climate enthusiasts in the Newport, Rhode Island area.
Dam Length |
400 |
Dam Height |
12 |
River Or Stream |
JAMESTOWN BROOK |
Primary Dam Type |
Earth |
Surface Area |
6 |
Hydraulic Height |
7 |
Drainage Area |
2 |
Nid Storage |
24 |
Structural Height |
12 |
Hazard Potential |
Significant |
Nid Height |
12 |
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.
Jamestown Lower Reservoir
Jamestown