R-4 Detention Dam

About R-4 Detention Dam

The primary purpose of R-4 Detention Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Clark County Public Works (local government). It impounds the Las Vegas Wash-tr near Las Vegas.

The dam stands 39 feet tall and stretches 1,151 feet across, creates a reservoir covering 35 acres, has a maximum storage capacity of 524 acre-feet, and collects water from a drainage area of 10 square miles. Completed in 2004, the structure is relatively new.

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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 02/25/2022.

At 39 feet, this dam is taller than 86% of dams nationwide.

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

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