Lake Elkhorn Reservoir Report

Last Updated: December 5, 2025

Lake Elkhorn, a private water resource nestled in Columbia, Maryland, is a picturesque oasis boasting a surface area of 49 acres and a maximum storage capacity of 910 acre-feet.


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Summary

Constructed in 1974 for flood risk reduction and recreation, this earth dam stands at a height of 26 feet and spans 662 feet along the Little Patuxent River. The dam's spillway, with a width of 145 feet, serves as an uncontrolled outlet for excess water, with a maximum discharge capacity of 9912 cubic feet per second.

Managed by the Maryland Dam Safety agency, Lake Elkhorn poses a high hazard potential but maintains a satisfactory condition assessment as of June 2018. The dam underwent structural modifications in 2001 to ensure its resilience. Despite the moderate risk assessment, the dam lacks an Emergency Action Plan (EAP) meeting guidelines, suggesting a need for improved emergency preparedness measures. With its tranquil waters and scenic surroundings, Lake Elkhorn serves as a vital recreational hub and critical flood control infrastructure in Howard County.

Years Modified

2001 - Structural

Year Completed

1974

Dam Length

662

Dam Height

26

River Or Stream

Little Patuxent River-TR

Primary Dam Type

Earth

Surface Area

49

Drainage Area

3.6

Nid Storage

910

Outlet Gates

Valve - 0

Hazard Potential

High

Foundations

Rock, Soil

Nid Height

26
       
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.