Little Raccoon Dam No. 2d - Dwyer Dam

About Little Raccoon Dam No. 2d - Dwyer Dam

The primary purpose of Little Raccoon Dam No. 2d - Dwyer 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 Little Raccoon Conservancy District (local government). It impounds the Unnamed Tributary Williams Creek near Rockville.

The dam stands 41 feet tall and stretches 460 feet across, creates a reservoir covering 92 acres, has a maximum storage capacity of 1,319 acre-feet, and collects water from a drainage area of 3 square miles. Completed in 1975, the structure is well into its service life at over 50 years 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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 12/11/2018. That was 7 years ago, which is on the longer end for a high-hazard structure.

At 41 feet, this dam is taller than 88% 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 Indiana dam safety program can provide more specific information about emergency planning for this structure.

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