Thrall Unit Flood Project Reservoir Report

Last Updated: December 5, 2025

The Thrall Unit Flood Project in Eureka, Kansas, is a privately owned structure regulated by the Kansas Department of Agriculture.


°F

°F

mph

Wind

%

Humidity

Summary

Built in 1950 by Sinclair Oil and Gas Co, this buttress dam on Swing Creek stands at 30 feet tall and stretches 990 feet in length, with a storage capacity of 230 acre-feet. Despite its low hazard potential, the dam has not been rated for its condition since its last inspection in 1950.

The project serves a primary purpose classified as "Other" and is designed to provide flood protection and water resource management in the region. Located in Greenwood County, Kansas, the dam's construction and operation fall under the jurisdiction of the state regulatory agency. With a maximum discharge of 1800 cubic feet per second, the Thrall Unit Flood Project plays a crucial role in mitigating flood risks and ensuring water security for the surrounding area.

As water resource and climate enthusiasts, the Thrall Unit Flood Project offers a fascinating case study in private dam ownership and management. With its historical significance dating back to the mid-20th century, this structure on Swing Creek continues to play a vital role in safeguarding the local community against potential flooding events. Its unique design and operational features make it a noteworthy example of sustainable water infrastructure in the state of Kansas.

Year Completed

1950

Dam Length

990

Dam Height

30

River Or Stream

SWING CREEK

Hydraulic Height

29

Nid Storage

230

Structural Height

30

Outlet Gates

None

Hazard Potential

Low

Foundations

Unlisted/Unknown

Nid Height

30
       
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.