Johnson Dam Site 1, located in Fairfield, Iowa, is a privately owned earth dam completed in 1993 by the NRCS. The dam's primary purposes include fire protection, stock, or small fish pond. With a height of 27 feet and a length of 580 feet, the dam has a storage capacity of 116 acre-feet and covers a surface area of 9.8 acres. It is regulated by the Iowa DNR and is inspected, permitted, and enforced by the state.

Situated on TR- Mitchell Creek, Johnson Dam Site 1 serves as a crucial water resource for the surrounding area, with a low hazard potential and a moderate risk assessment rating. While the dam is currently deemed to be in "Not Rated" condition, its emergency action plan status, inundation maps, and risk management measures are not fully updated. The dam's location in Jefferson County, Iowa, makes it a valuable asset for water conservation and management in the region.

Overall, Johnson Dam Site 1 plays a significant role in providing essential water resources for fire protection, stock, and small fish pond purposes in Fairfield, Iowa. As a state-regulated structure with a low hazard potential, the dam ensures water storage and management in the area. However, there is room for improvement in updating emergency preparedness plans and risk management measures to enhance the dam's overall safety and resilience in the face of potential climate challenges and water resource management needs.