Hern Lake Dam Reservoir Report

Last Updated: December 21, 2025

Hern Lake Dam, located in Morgan County, Indiana, is a privately owned earth dam constructed in 1968 with a primary purpose of recreation.


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Summary

Standing at a height of 20 feet and with a structural height of 23 feet, the dam provides a normal storage capacity of 32 acre-feet and a maximum storage of 50 acre-feet. It spans 300 feet in length and covers a surface area of 4 acres.

Despite its low hazard potential, Hern Lake Dam has been assessed to be in poor condition as of its last inspection in May 2000. The dam is maintained by the Natural Resources Conservation Service and is not regulated or inspected by the state of Indiana. With no associated structures and no state permitting or enforcement requirements, Hern Lake Dam serves as a recreational hub in the Paragon-Offstream area, offering opportunities for boating, fishing, and other water-related activities along the TR-Fall Creek waterway.

As water resource and climate enthusiasts explore the intricacies of Hern Lake Dam, they can appreciate its role in providing recreational opportunities while also noting the need for continued monitoring and maintenance to ensure its safety and longevity. The dam's location within the Louisville District and its historical significance as a part of Indiana's water infrastructure highlight the intersection of human development and environmental stewardship in managing water resources for the benefit of both residents and wildlife in the region.

Year Completed

1968

Dam Length

300

Dam Height

20

River Or Stream

TR-FALL CREEK

Primary Dam Type

Earth

Surface Area

4

Hydraulic Height

20

Nid Storage

50

Structural Height

23

Hazard Potential

Low

Nid Height

23
       
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.