Winner Dam, located in Missouri Valley, Iowa, is a privately-owned structure designed by the USDA NRCS and regulated by the Iowa DNR. Completed in 2011, this earth dam stands 41 feet tall and stretches 800 feet in length, serving primarily for flood risk reduction. With a storage capacity of 190 acre-feet and a surface area of 8 acres, Winner Dam plays a crucial role in managing water resources for the surrounding area.

The dam also serves multiple purposes including fish and wildlife pond creation, grade stabilization, and recreation. With a low hazard potential and not yet rated for condition assessment, Winner Dam remains a reliable asset for the community. Despite not having any associated structures or outlet gates, the dam's construction and operation are overseen by the Natural Resources Conservation Service, ensuring its effectiveness in protecting against floods and contributing to the local ecosystem.

With its strategic location along a tributary to Thompson Creek, Winner Dam plays a vital role in water management for Harrison County, Iowa. As a key element in flood risk reduction efforts, this structure demonstrates the importance of sustainable water resource management and the collaboration between private owners, regulatory agencies, and design experts in safeguarding the local environment and community from potential water-related hazards.