Katy Allen Lake Dam

About Katy Allen Lake Dam

The primary purpose of Katy Allen Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Vernon County Mo (private). It impounds the Willow Branch near Nevada.

The dam stands 25 feet tall, creates a reservoir covering 12 acres, has a maximum storage capacity of 160 acre-feet, and collects water from a drainage area of 625 square miles. Completed in 1910, 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. The most recent inspection on record was 06/21/1979. That was 46 years ago — unusually long for a high-hazard dam, which typically requires more frequent inspections.

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

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