Cedar Lake (Old Olathe Lake) Reservoir Report

Last Updated: December 6, 2025

Cedar Lake, also known as Old Olathe Lake, is a picturesque water resource located in Bonner Springs, Kansas.


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Summary

Built in 1931 by E T Archer and Co, this earth dam stands at a height of 38.5 feet and serves as a vital water supply source for the region. With a normal storage capacity of 705 acre-feet, Cedar Lake covers a surface area of 55 acres and is fed by the Cedar Creek-TR river system.

Despite its historic significance and essential role in water supply, Cedar Lake faces some challenges. With a high hazard potential and a poor condition assessment, this dam requires regular inspection and maintenance to ensure its safety and functionality. The Kansas Department of Agriculture oversees the regulatory aspects of Cedar Lake, with state permitting and enforcement in place to safeguard the surrounding communities from any potential risks associated with the dam.

Located in Johnson County, Kansas, Cedar Lake not only provides water supply but also offers a serene environment for outdoor enthusiasts to enjoy. As climate change continues to impact water resources, the conservation and management of dams like Cedar Lake become increasingly important to ensure sustainable water supply for future generations.

Year Completed

1931

Dam Length

800

Dam Height

38.5

River Or Stream

CEDAR CREEK-TR

Primary Dam Type

Earth

Surface Area

55

Hydraulic Height

32

Drainage Area

5.97

Nid Storage

1004

Structural Height

38

Outlet Gates

None

Hazard Potential

High

Foundations

Unlisted/Unknown

Nid Height

39
       
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.