Giles

About Giles

The primary purpose of Giles is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Mr. Robert And Mrs. Jean Brown (private). It impounds the Tr Sweeney Cr near Vacaville.

The dam stands 18 feet tall and stretches 695 feet across, creates a reservoir covering 17 acres, has a maximum storage capacity of 119 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1965, the structure is well into its service life at over 50 years old.

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 poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 12/01/2025.

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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