Shores Of Calvert Upper Dam (Rivershore Drive) Reservoir Report

Last Updated: December 5, 2025

The Shores of Calvert Upper Dam on Rivershore Drive in Dunkirk, Maryland, is a private recreational dam completed in 1972 by designers RA Barrett and Mike Rodevick.


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Summary

This earth dam stands at a height of 25 feet and has a length of 275 feet, providing a storage capacity of 50 acre-feet. Situated on the Patuxent River, the dam serves the primary purpose of recreation, offering a surface area of 7 acres for water enthusiasts to enjoy.

Despite its recreational benefits, the Shores of Calvert Upper Dam poses a significant hazard potential due to its poor condition assessment as of April 2021. The dam has undergone structural modifications in 2006 to address safety concerns, but its risk assessment remains at a moderate level. With a drainage area of 0.33 square miles and a maximum discharge capacity of 125 cubic feet per second, the dam's uncontrolled spillway and inadequate outlet gates raise concerns for potential emergencies.

Water resource and climate enthusiasts interested in the Shores of Calvert Upper Dam can appreciate its location within Calvert County, Maryland, and its proximity to the Baltimore District of the US Army Corps of Engineers. The dam is regulated by the Maryland Dam Safety agency, with state permitting, inspection, and enforcement in place to ensure public safety. Despite its challenges, the dam continues to provide recreational opportunities for local residents and visitors to enjoy the beauty of the Patuxent River.

Years Modified

2006 - Structural

Year Completed

1972

Dam Length

275

Dam Height

25

River Or Stream

Patuxent River-TR

Primary Dam Type

Earth

Surface Area

7

Drainage Area

0.33

Nid Storage

50

Outlet Gates

Needle - 0

Hazard Potential

Significant

Foundations

Soil

Nid Height

25
       
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.