Twelvemile Watershed Site D-60 in Union, Iowa, is a vital water resource managed by the local government with oversight from the Iowa Department of Natural Resources. This earth dam, completed in 1999 by the USDA NRCS, serves multiple purposes including fire protection, stock watering, and flood risk reduction. With a height of 35 feet and a storage capacity of 497 acre-feet, this dam plays a crucial role in managing water resources in the region.

Situated along Twelvemile Creek, this dam covers a surface area of 14.9 acres and has a drainage area of 1.66 square miles. Despite its uncontrolled spillway type and low hazard potential, the dam is rated as being in moderate risk condition. With no recent inspection data available, the risk management measures and emergency preparedness of this site remain unclear. Overall, Twelvemile Watershed Site D-60 stands as a significant infrastructure for water management and conservation efforts in the area, contributing to the environmental sustainability of the region.

As a key component of the water infrastructure in Afton, Iowa, Twelvemile Watershed Site D-60 embodies the collaborative efforts of various agencies and stakeholders. With its primary purpose being fire protection and stock watering, this dam also provides essential flood risk reduction benefits to the community. While the dam's condition assessment is currently not rated, its role in managing water resources and mitigating potential hazards underscores the importance of ongoing monitoring and maintenance to ensure its continued functionality for the region's water supply and environmental health.