Carlton Lake #1

About Carlton Lake #1

The primary purpose of Carlton Lake #1 is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Carlton Creek Irrigation (private). It impounds the Carlton Creek near Lolo.

The dam stands 22 feet tall and stretches 420 feet across, creates a reservoir covering 40 acres, has a storage capacity of 450 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1899, 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. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 07/17/2024.

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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