The Mill Picayune Watershed Site M-18-4, located in Shelby County, Iowa, is a crucial water resource managed by the local government for various purposes such as fire protection, stock, small fish pond, and flood risk reduction. This earth dam, completed in 1978, stands at a height of 48 feet and has a storage capacity of 68 acre-feet. The watershed covers a drainage area of 0.19 square miles and has a surface area of 3 acres, serving as a vital water management infrastructure in the region.

Managed by the USDA NRCS, this watershed site on TR-Mill Creek plays a significant role in regulating water flow and providing essential services to the community. With a low hazard potential and a moderate risk level, this structure is inspected, permitted, and regulated by the Iowa DNR, ensuring its safety and functionality. Despite not being rated for condition, the Mill Picayune Watershed Site M-18-4 remains a critical asset in water resource management and climate resilience efforts in the area.

With its strategic location and design, the Mill Picayune Watershed Site M-18-4 contributes to the overall water management strategy in the region, enhancing flood risk reduction and providing valuable water resources for various purposes. As a part of the comprehensive water infrastructure network, this site highlights the importance of sustainable water resource management and climate adaptation in safeguarding communities against water-related risks.