Anthon Subwatershed M-4001, located in Anthon, Iowa, is a key water resource managed by the local government for purposes such as fire protection, stock, or small fish pond management, and flood risk reduction. Built in 1954 by the USDA NRCS, this Earth-type dam stands 28 feet tall and spans 400 feet, with a storage capacity of 37 acre-feet and a surface area of 1.3 acres. Situated on the TR-Little Sioux River, this dam plays a vital role in managing water flow and reducing flood risks in the region.

With a low hazard potential and a moderate risk assessment rating, Anthon Subwatershed M-4001 is currently not rated for its condition but is regulated, permitted, inspected, and enforced by the Iowa Department of Natural Resources. Although it has not undergone recent inspections or assessments, the dam continues to serve its primary purposes effectively. The surrounding area, including Woodbury County in Iowa, benefits from the water management and flood control provided by this structure, ensuring the safety and sustainability of the local ecosystem and communities. With its long history and continued relevance in water resource management, Anthon Subwatershed M-4001 remains a critical asset in the region's efforts to address climate-related challenges and ensure water security for all stakeholders.