Katy Lake Dam Reservoir Report

Last Updated: December 8, 2025

Katy Lake Dam, located in Mokane, Missouri, was completed in 1905 by the M-K-T Railroad and Thomas Wilcox.


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Summary

This private-owned dam spans 323 feet in length and stands at 44 feet tall, serving a primary purpose of flood risk reduction. It sits on Ewing Creek, within the St. Louis District, and is regulated by the Dam and Reservoir Safety Program of Missouri.

With a storage capacity of 273 acre-feet and a surface area of 14 acres, Katy Lake Dam plays a crucial role in the irrigation, recreation, and water supply needs of the surrounding area. Despite its high hazard potential and moderate risk assessment, the dam is in satisfactory condition as of its last assessment in 2009. Regular inspections are conducted every three years to ensure the safety and integrity of the structure.

Enthusiasts of water resources and climate will find Katy Lake Dam a fascinating example of early 20th-century engineering for flood risk reduction. Its historical significance, coupled with its modern-day functionality and regulatory oversight, highlights the importance of maintaining and managing such critical infrastructure in the face of changing environmental conditions and increasing water demands.

Year Completed

1905

Dam Length

323

Dam Height

44

River Or Stream

EWING CREEK

Primary Dam Type

Earth

Surface Area

14

Drainage Area

575

Nid Storage

273

Structural Height

45

Outlet Gates

None

Hazard Potential

High

Foundations

Rock, Soil

Nid Height

45
       
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.