Big Rock Lake Dam Reservoir Report

Last Updated: December 5, 2025

Big Rock Lake Dam, located in Leetonia, Ohio, is a privately owned structure designed by Robert Mesmer, Sr.


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Summary

The dam, completed in 1963, serves primarily for recreational purposes, with a normal storage capacity of 99.1 acre-feet and a maximum storage of 159 acre-feet. The dam stands at a height of 32.2 feet and spans a length of 970 feet, creating a surface area of 12.8 acres and serving a drainage area of 0.46 square miles.

Managed by the Department of Natural Resources in Ohio, Big Rock Lake Dam has a low hazard potential and is assessed to be in fair condition as of the last inspection in May 2019. The dam is subject to state regulation, permitting, inspection, and enforcement, ensuring its safety and compliance with relevant standards. With its picturesque location in Columbiana County, the dam provides opportunities for outdoor recreation and contributes to the surrounding ecosystem as a tributary to the East Branch river.

Water resource and climate enthusiasts can appreciate the role of Big Rock Lake Dam in providing a serene recreational spot while maintaining a balance with its environmental impact and safety standards. Its historical significance, design features, and operational aspects make it an intriguing site for those interested in the intersection of water management, infrastructure, and natural landscapes. The dam's presence in the Pittsburgh District adds to its regional importance and highlights the interconnectedness of water resources across different areas.

Year Completed

1963

Dam Length

970

Dam Height

32.2

River Or Stream

TRIBUTARY TO EAST BRANCH

Primary Dam Type

Earth

Surface Area

12.8

Drainage Area

0.46

Nid Storage

159

Hazard Potential

Low

Nid Height

32
       
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.