Mcmillan Lake Dam Reservoir Report

Last Updated: December 5, 2025

Mcmillan Lake Dam, also known as Porter Lake, is a privately owned structure located in Muskingum County, Ohio.


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Summary

Built in 1963 by the USDA NRCS, this earth dam stands at a height of 26.5 feet and stretches 490 feet in length. With a primary purpose of recreation, the dam provides a storage capacity of 40.9 acre-feet and covers a surface area of 4.3 acres.

Regulated by the Department of Natural Resources in Ohio, Mcmillan Lake Dam has a low hazard potential and is in fair condition as of the last assessment in October 2018. The dam has an uncontrolled spillway and outlet gates, with a maximum discharge rate of 213 cubic feet per second. Despite its moderate risk assessment, the dam meets regulatory guidelines and undergoes regular inspections every five years to ensure its continued safety and functionality.

Situated in the vicinity of the Kent Run tributary, Mcmillan Lake Dam offers a peaceful recreational setting for water resource and climate enthusiasts to explore and enjoy. With its picturesque surroundings and maintained infrastructure, this dam serves as both a practical water management tool and a leisure destination for outdoor enthusiasts in the White Cottage area of Ohio.

Year Completed

1963

Dam Length

490

Dam Height

26.5

River Or Stream

TRIBUTARY TO KENT RUN

Primary Dam Type

Earth

Surface Area

4.3

Drainage Area

0.09

Nid Storage

40.9

Outlet Gates

Uncontrolled

Hazard Potential

Low

Foundations

Soil

Nid Height

27
       
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.