Three D Dam, located in Maxwell, Iowa, is a privately owned structure designed by the USDA NRCS with a primary purpose of fire protection, stock, or small fish pond. Completed in 1971, this earth dam stands at a height of 34 feet and has a length of 295 feet, providing a storage capacity of 209 acre-feet. The dam is regulated by the Iowa DNR and undergoes state permitting, inspection, and enforcement to ensure its safety and functionality.

The dam, situated on TR-NEST INDIAN CREEK in Story County, Iowa, has a low hazard potential and a moderate risk assessment. It serves not only for fire protection and recreational purposes but also contributes to the local ecosystem by providing habitat for small fish. With a surface area of 8.9 acres and a drainage area of 0.59 square miles, the dam plays a crucial role in managing water resources and mitigating flood risks in the region.

Despite being privately owned, Three D Dam's importance extends beyond just its primary purposes as it also offers a serene recreational spot for visitors to enjoy. With its strategic location and design, the dam showcases the innovative collaboration between private owners and government agencies to protect water resources and promote sustainable practices in the face of climate challenges.