Thomas Dam, located in Jackson County, Iowa, was completed in 1959 by the USDA SCS and serves multiple purposes including fire protection, stock, and small fish pond. The earth dam stands at 19 feet high and stretches 350 feet in length, with a storage capacity of 55 acre-feet. Situated on the TR-South Fork Maquoketa River, the dam has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment.

Despite not being federally owned or funded, Thomas Dam is regulated and permitted by the Iowa DNR, with state jurisdiction, inspection, and enforcement in place. The dam is in compliance with state regulations and has a moderate risk assessment rating of 3. Although the last inspection date was in 1980, the dam continues to meet guidelines and has not experienced any major modifications in recent years. While the spillway is uncontrolled, the dam poses minimal risk to the surrounding area and remains a vital resource for water management in the region.

For water resource and climate enthusiasts, Thomas Dam serves as a fascinating example of sustainable infrastructure in a rural setting. With its strategic location on the Maquoketa River and multiple uses, the dam highlights the importance of maintaining and regulating water resources for various purposes. Additionally, the dam's low hazard potential and moderate risk assessment demonstrate effective management and monitoring practices, ensuring the safety and functionality of the structure for years to come.