Mill Picayune Watershed Site B-3 is a flood risk reduction structure located in Harrison County, Iowa, along the TR-PICAYUNE CREEK. Built in 1962 by the USDA NRCS, this earth dam stands at a height of 38 feet and has a length of 493 feet, providing storage of 247 acre-feet of water. With a normal storage capacity of 70 acre-feet and a surface area of 8.9 acres, this site plays a crucial role in mitigating flood risks in the area.

Managed by the local government and regulated by the Iowa DNR, this dam has a high hazard potential but is currently assessed as satisfactory in condition. The spillway, with a width of 3 feet, is uncontrolled, and the structure is inspected every two years to ensure its integrity. While the primary purpose of this dam is flood risk reduction, it also serves other purposes such as recreation, highlighting its importance as a multi-functional water resource management system in the region.

Overall, Mill Picayune Watershed Site B-3 is a vital piece of infrastructure in Harrison County, Iowa, contributing to the protection of the local community from flooding events. With its strategic location, effective design, and regular maintenance, this dam exemplifies the intersection of water resource management and climate resilience, showcasing the importance of sustainable infrastructure for safeguarding against natural hazards in the area.