Simpson Dam, located in Decatur, Iowa, is a private earth dam designed by the USDA NRCS and completed in 1991. This dam serves multiple purposes including fire protection, livestock management, and as a small fish pond. With a height of 28 feet and a length of 500 feet, Simpson Dam has a storage capacity of 155 acre-feet and covers a surface area of 9.1 acres. It is regulated by the Iowa Department of Natural Resources and undergoes regular inspections and permitting to ensure its safety and compliance with state regulations.

The dam, situated on TR- Marks Creek, has a low hazard potential and a moderate risk assessment score. While it does not have an Emergency Action Plan in place, Simpson Dam meets state guidelines and is equipped with an uncontrolled spillway. As a key water resource in the area, the dam plays a crucial role in managing water levels, providing irrigation for agriculture, and supporting wildlife habitats. With its strategic location and efficient design, Simpson Dam stands as a testament to effective water resource management and climate adaptation efforts in the region.

Owned by a private entity, Simpson Dam demonstrates the partnership between private owners and state regulatory agencies in ensuring the safety and functionality of essential water infrastructure. As water resource and climate enthusiasts, the presence of Simpson Dam serves as a reminder of the importance of sustainable water management practices and the need for continued investment in infrastructure to mitigate the impacts of climate change on water resources.