Topaz Lake Reservoir Report

Last Updated: December 5, 2025

Topaz Lake, located in Mono County, California, is a vital reservoir managed by the public utility for flood risk reduction, irrigation, and water supply.


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Summary

The earth dam, standing at 11 feet tall, was completed in 1937 and has a storage capacity of 59,600 acre-feet. The reservoir covers an area of 2,200 acres and is fed by the Walker River, providing essential water resources for the region.

With its high hazard potential, Topaz Lake is regularly inspected and maintained to ensure its structural integrity and safety. The dam has been deemed to be in satisfactory condition, with the last assessment conducted in September 2017. The public utility is responsible for the operation, inspection, and enforcement of regulations to mitigate risks and ensure the reservoir's continued functionality in the face of climate challenges.

Topaz Lake serves as a crucial water management infrastructure in California, supporting various purposes and providing essential resources to the surrounding communities. As climate change poses increasing threats to water resources, the proper regulation and maintenance of reservoirs like Topaz Lake are paramount to safeguarding the region's water supply and mitigating flood risks for the future.

Year Completed

1937

Dam Length

11100

Dam Height

11

River Or Stream

Walker River

Primary Dam Type

Earth

Surface Area

2200

Hydraulic Height

6.8

Drainage Area

410

Nid Storage

59600

Hazard Potential

High

Nid Height

11
       
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.