Mills Lake Dam Reservoir Report

Last Updated: December 5, 2025

Mills Lake Dam, located in Hanover, Ohio, is a private earth dam completed in 1965 for recreational purposes.


°F

°F

mph

Wind

%

Humidity

Summary

The dam stands at a height of 25.3 feet and has a length of 260 feet, providing a storage capacity of 21.3 acre-feet. Despite its primary function for recreation, the dam also serves as a critical structure for managing the flow of the tributary to Rocky Fork River.

Maintained by the Department of Natural Resources in Ohio, Mills Lake Dam has a significant hazard potential and is currently assessed to be in poor condition as of the last inspection in December 2020. Although it meets state regulatory standards for permitting, inspection, and enforcement, the dam poses a potential risk that requires effective risk management measures. With a drainage area of 0.14 square miles and a maximum discharge capacity of 194 cubic feet per second, the dam plays a crucial role in water resource management in the region.

Enthusiasts of water resources and climate will find Mills Lake Dam an intriguing structure that not only enhances recreational opportunities but also highlights the importance of proper maintenance and risk assessment for earth dams. As a key component of the local water infrastructure, the dam underscores the ongoing need for proactive monitoring and management to ensure the safety and sustainability of water resources in Licking County, Ohio.

Year Completed

1965

Dam Length

260

Dam Height

25.3

River Or Stream

TRIBUTARY TO ROCKY FORK

Primary Dam Type

Earth

Surface Area

2

Drainage Area

0.14

Nid Storage

21.3

Hazard Potential

Significant

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.