Pear Lake Dam

About Pear Lake Dam

The primary purpose of Pear Lake Dam is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Beaverhead Water Co (private). It impounds the Birch Creek near Twin Bridges.

The dam stands 19 feet tall and stretches 397 feet across, creates a reservoir covering 43 acres, has a maximum storage capacity of 481 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1904, the structure is over a century 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 09/18/2024.

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 Montana dam safety program can provide more specific information about emergency planning for this structure.

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