Ballew Gsd No 21, also known as Little Delaware Mission Cr WS Dam 21, is a local government-owned structure located in Horton, Kansas. This earth dam primarily serves the purpose of debris control along Grasshopper Creek-TR. Designed by the USDA NRCS, the dam stands at a height of 25 feet with a hydraulic height of 22 feet and a length of 620 feet. It has a storage capacity of 130 acre-feet and covers a surface area of 5.08 acres, making it a crucial asset for managing water resources in the region.

With a low hazard potential and a moderate risk assessment rating of 3, Ballew Gsd No 21 plays a vital role in mitigating potential risks associated with its operation. Although the dam has not been inspected since August 2005 and is currently rated as "Not Rated" for its condition assessment, it still serves as a key structure for water resource management in Brown County, Kansas. While it may not be state-regulated or permitted, its presence contributes to the overall resilience of the local water infrastructure in the area.

Despite its age and lack of recent inspections, Ballew Gsd No 21 remains an important component of the water management system in the region. With its low hazard potential and moderate risk assessment, the dam continues to provide valuable debris control and water storage capabilities along Grasshopper Creek-TR. As climate change impacts water resources, structures like Ballew Gsd No 21 will become even more crucial in ensuring the sustainable management of water in the face of evolving environmental challenges.