Gilbert Run Dam 3 (Jameson Dam) Reservoir Report

Last Updated: December 5, 2025

Gilbert Run Dam 3, also known as Jameson Dam, is a key flood risk reduction structure located in the Gilbert Run watershed in Charles County, Maryland.


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Summary

Built in 1964 by the USDA NRCS, this earth dam stands at a height of 37 feet and spans 950 feet in length, with a normal storage capacity of 205 acre-feet. The dam plays a crucial role in protecting the area from potential flooding, with a maximum discharge capacity of 8,900 cubic feet per second.

Despite its important function, Gilbert Run Dam 3 has been assessed as being in unsatisfactory condition with a high hazard potential, highlighting the need for ongoing maintenance and inspection. The dam is regulated by the Maryland Dam Safety agency and undergoes regular inspections to ensure its structural integrity. While the risk assessment indicates a moderate level of risk, there is a focus on implementing risk management measures to mitigate potential hazards and ensure the safety of the surrounding community.

Visitors to the area can also enjoy recreational activities at the dam, such as fishing and boating on the 47-acre surface area created by the dam. With its picturesque location in Newport, Maryland, and the Gilbert Run stream flowing nearby, Gilbert Run Dam 3 serves both practical and leisure purposes for water resource and climate enthusiasts alike.

Year Completed

1964

Dam Length

950

Dam Height

37

River Or Stream

Gilbert Run

Primary Dam Type

Earth

Surface Area

47

Drainage Area

4.3

Nid Storage

2900

Outlet Gates

Slide (sluice gate) - 0

Hazard Potential

High

Foundations

Soil

Nid Height

37
       
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.