Kossler Reservoir Report

Last Updated: December 5, 2025

Located in Eldorado Springs, Colorado, Kossler is a local government-owned dam with a primary purpose of hydroelectric power generation.


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Summary

Built in 1909, this earth dam stands at a height of 20 feet and stretches 450 feet in length. With a storage capacity of 220 acre-feet and a normal storage level of 180 acre-feet, Kossler utilizes the waters of Woods Gulch for its operations.

The dam has been deemed to have a high hazard potential, but its condition assessment as of June 2020 was reported as satisfactory. Kossler's spillway type is uncontrolled with a width of 22 feet, and it has a maximum discharge capacity of 300 cubic feet per second. In the event of an emergency, the dam's emergency action plan (EAP) was last revised in May 2014, and it meets regulatory guidelines.

For water resource and climate enthusiasts, Kossler serves as a notable example of a historic dam that continues to play a vital role in hydroelectric power generation. With its location in the scenic Boulder County, this dam not only provides renewable energy but also underscores the importance of proper maintenance and emergency preparedness in ensuring the safety and efficiency of water infrastructure.

Year Completed

1909

Dam Length

450

Dam Height

20

River Or Stream

WOODS GULCH

Primary Dam Type

Earth

Surface Area

13

Hydraulic Height

20

Nid Storage

220

Structural Height

20

Hazard Potential

High

Nid Height

20
       
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.