Crater Lake Reservoir Report

Last Updated: December 5, 2025

Crater Lake, located in Alpine County, California, is a privately owned dam that serves as a water supply for the surrounding area.


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Summary

Built in 1937, this earth dam stands at a height of 36 feet and has a hydraulic height of 28 feet. With a storage capacity of 320 acre-feet, the dam impounds Crater Lake Creek and covers a surface area of 20 acres.

Despite its age, Crater Lake Dam has been well-maintained, with a low hazard potential and a satisfactory condition assessment as of September 2017. The dam is regulated by the California Department of Water Resources (DWR) under the Safety of Dams program, ensuring that it meets all necessary safety standards. The last inspection of the dam was conducted in June 2020, with a regular inspection frequency of once per year.

For water resource and climate enthusiasts, Crater Lake Dam represents a vital piece of infrastructure that plays a key role in providing irrigation and water supply to the local community. Its serene surroundings and important function make it a noteworthy site for those interested in the intersection of water management and environmental conservation in California's diverse landscape.

Year Completed

1937

Dam Length

220

Dam Height

36

River Or Stream

Crater Lake Creek

Primary Dam Type

Earth

Surface Area

20

Hydraulic Height

28

Drainage Area

0.55

Nid Storage

320

Hazard Potential

Low

Nid Height

36
       
Seasonal Comparison

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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.