Mallon Lake Reservoir Report

Last Updated: December 5, 2025

Mallon Lake, located in Lyon County, Kansas, is a privately owned earth dam structure with a primary purpose of recreation.


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Summary

Completed in 2001, the dam stands at a height of 23 feet and has a storage capacity of 237.55 acre-feet, with a normal storage level of 88.57 acre-feet. The surface area of the lake spans 16.14 acres, with a drainage area of 0.34 square miles.

Situated on the Neosho River, Mallon Lake offers a serene setting for water resource and climate enthusiasts to explore. The low hazard potential of the dam, combined with its not rated condition assessment, provides a safe environment for recreational activities such as fishing, boating, and wildlife observation. The dam's proximity to Emporia, Kansas, makes it a convenient destination for outdoor enthusiasts looking to connect with nature.

With its tranquil waters and picturesque surroundings, Mallon Lake is a hidden gem in the heart of Lyon County. Managed by the Kansas Department of Agriculture, this recreational oasis offers a peaceful retreat for visitors seeking to immerse themselves in the beauty of Kansas' natural landscapes. Whether you're a water resource enthusiast or a climate advocate, Mallon Lake provides the perfect setting to appreciate the interconnectedness of water, climate, and the environment.

Year Completed

2001

Dam Length

1018

Dam Height

23

River Or Stream

NEOSHO RIVER-TR

Primary Dam Type

Earth

Surface Area

16.14

Drainage Area

0.34

Nid Storage

237.55

Outlet Gates

None

Hazard Potential

Low

Foundations

Unlisted/Unknown

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.