Thompson Lake Dam Reservoir Report

Last Updated: December 5, 2025

Thompson Lake Dam, located in Ashland, Ohio, is a privately owned structure that serves primarily for recreational purposes.


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Summary

Built in 1972, this earth dam stands at a height of 16.2 feet and has a storage capacity of 33.4 acre-feet. The dam is situated on a tributary to the Black Fork Mohican River, providing a serene setting for outdoor enthusiasts to enjoy water-based activities such as fishing and boating.

Despite its recreational value, Thompson Lake Dam has been assessed as having poor condition and significant hazard potential. The dam's last inspection in December 2019 revealed the need for maintenance and improvement to ensure its safety and functionality. The Ohio Department of Natural Resources regulates and inspects the dam regularly, highlighting the importance of proper upkeep and monitoring to mitigate risks associated with its operation.

With a drainage area of 0.04 square miles and a surface area of 5.2 acres, Thompson Lake Dam plays a crucial role in managing water flow and storage in the region. Its proximity to the Black Fork Mohican River adds to its significance in the local ecosystem. Water resource and climate enthusiasts can appreciate the balance between recreation and conservation that this dam represents, underscoring the importance of sustainable water management practices for future generations.

Year Completed

1972

Dam Length

545

Dam Height

16.2

River Or Stream

TRIBUTARY TO BLACK FORK MOHICAN RIVER - OFFSTREAM

Primary Dam Type

Earth

Surface Area

5.2

Drainage Area

0.04

Nid Storage

33.4

Hazard Potential

Significant

Nid Height

16
       
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.