Thompson Dam, located in Cainsville, Missouri, serves multiple purposes including fire protection, stock, and small fish pond. Owned privately, the dam was completed in 1965 and has a height of 29 feet and a length of 445 feet. With a storage capacity of 49 acre-feet and a surface area of 4 acres, the dam plays a crucial role in managing water resources in the area.

Managed by the Natural Resources Conservation Service, Thompson Dam is regulated by the Iowa Department of Natural Resources. Despite its low hazard potential, the dam is considered to have a moderate risk level. The dam is primarily made of earth and soil, with an uncontrolled spillway type. Although last inspected in 1968, the dam's condition is currently marked as "Not Rated," indicating the need for further assessment and potential maintenance.

With its location on TR-Indian Creek and its role in water management for Decatur County, Iowa, Thompson Dam is a significant structure for the region's water resource and climate enthusiasts. The dam's presence not only supports fire protection and agricultural activities but also highlights the importance of maintaining and monitoring such critical infrastructure in the face of changing climate conditions.