Amethyst Basin

About Amethyst Basin

The primary purpose of Amethyst Basin 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 County Of San Bernardino Department Of Public Works (local government). It impounds the Unnamed near Victorville.

The dam stands 45 feet tall and stretches 600 feet across, creates a reservoir covering 20 acres, has a maximum storage capacity of 347 acre-feet, and collects water from a drainage area of 6 square miles. Completed in 2019, the structure is relatively new.

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 03/12/2025.

At 45 feet, this dam is taller than 91% of dams nationwide.

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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