Thompson Dam, located in Avoca, Iowa, was completed in 1974 and is primarily used for fire protection, stock, and small fish pond purposes. This earth dam has a height of 26 feet, a length of 478 feet, and a storage capacity of 140 acre-feet. Situated on the TR-East Br West Nisanabota river, the dam is owned and regulated by a private entity but falls under the jurisdiction of the Iowa Department of Natural Resources.

The dam, designed by USDA NRCS, has a low hazard potential and a moderate risk assessment rating. While it has not been inspected since 1978, it is deemed to be in good condition. The dam does not have any associated structures or outlet gates, and its spillway type is uncontrolled. Despite its age, Thompson Dam continues to serve its intended purposes effectively and contributes to the water resource management in Shelby County, Iowa.

Water resource and climate enthusiasts will appreciate Thompson Dam for its role in providing essential services such as fire protection and stock pond storage. With its location in a rural area and limited drainage area, the dam serves as a valuable asset for local water management. The dam's design by the Natural Resources Conservation Service underscores a commitment to sustainable water infrastructure, while its oversight by the Iowa DNR ensures compliance with state regulations. Thompson Dam stands as a testament to effective dam engineering and maintenance practices, contributing to the resilience of water resources in the region.