Thompson

About Thompson

The primary purpose of Thompson 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 Southern California Edison (private). It impounds the Middle Canyon.

The dam stands 114 feet tall and stretches 445 feet across, creates a reservoir covering 54 acres, has a maximum storage capacity of 1,010 acre-feet, and collects water from a drainage area of 8 square miles. Completed in 1925, the structure is over a century old.

This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. 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 12/04/2024.

At 114 feet, this dam is taller than 98% of all dams in the United States.

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