Farm Dam in Decatur, Iowa, serves multiple purposes including fire protection, stock, and small fish pond. Built in 1987 by USDA NRCS, this private dam stands at 30 feet tall and spans 415 feet in length, with a capacity to hold 29 acre-feet of water. Located along the TR- Thompson River, this earth dam with a soil foundation is regulated by the Iowa DNR and undergoes regular inspections and enforcement to ensure safety and compliance.

With a low hazard potential and a moderate risk assessment rating, Farm Dam is considered a crucial water resource in the area, providing essential functions for both agricultural and ecological purposes. Although the dam is currently in a "Not Rated" condition, its design and purpose indicate its importance in the local landscape. The dam's proximity to Westerville and its strategic location within the drainage area further highlight its significance in water management and conservation efforts.

Managed by private owners and supported by the Natural Resources Conservation Service, Farm Dam showcases the collaborative efforts between government agencies and private entities in safeguarding water resources. As a key feature in the Rock Island District, this dam plays a vital role in maintaining water supply, mitigating potential risks, and supporting sustainable practices in water resource management. Its presence underscores the importance of investing in infrastructure for climate resilience and ensuring the long-term sustainability of water systems in the region.