Johnston Dam, located in Keosauqua, Iowa, is a privately owned structure designed by the USDA NRCS for fire protection, stock, or small fish pond purposes. Completed in 1962, this earth dam stands at a height of 33 feet and spans 452 feet in length, with a storage capacity of 250 acre-feet. Situated on the TR-Des Moines river, the dam serves as a crucial water resource for the region, with a normal storage capacity of 117 acre-feet and a surface area of 12.4 acres.

Managed by the Iowa DNR and regulated at the state level, Johnston Dam has a low hazard potential and a moderate risk assessment rating of 3. Despite not being recently rated for its condition, the dam has undergone state inspection, permitting, and enforcement, ensuring its safety and functionality. With its uncontrolled spillway type and soil foundation, Johnston Dam continues to play a significant role in water management and conservation efforts in Van Buren County, Iowa.

Water resource and climate enthusiasts will appreciate Johnston Dam's contribution to local water storage and management, as well as its design for multiple beneficial purposes. As a privately owned structure with state regulation and inspection, the dam serves as a vital asset for fire protection and agricultural needs in the region. With its historical significance dating back to the 1960s, Johnston Dam remains a key feature in the local landscape, supporting the community's water resource resilience and sustainability efforts.