Topaz Lake

About Topaz Lake

The primary purpose of Topaz Lake is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Walker River Irrigation District (public utility). It impounds the Walker River near Yerington, Nevada.

The dam stands 11 feet tall and stretches 11,100 feet across, creates a reservoir covering 2,200 acres, has a maximum storage capacity of 59,600 acre-feet, and collects water from a drainage area of 410 square miles. Completed in 1937, the structure is well-established, with more than 75 years of service.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. An emergency action plan is in place for this dam. The most recent inspection on record was 04/22/2025.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The California dam safety program can provide more specific information about emergency planning for this structure.

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