Tarsney Lake Dam

About Tarsney Lake Dam

The primary purpose of Tarsney Lake Dam is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Jackson Co. Public Works (local government). It impounds the Tr Sni-a-bar Creek near Grain Valley.

The dam stands 29 feet tall, creates a reservoir covering 17 acres, has a maximum storage capacity of 264 acre-feet, and collects water from a drainage area of 486 square miles. Completed in 1927, the structure is well-established, with more than 75 years of service.

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 04/11/1978. That was 48 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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