Cowles Dam, located in Decatur, Iowa, is a privately owned structure with a primary purpose of fire protection, stock, or small fish pond. Built in 1991 by the USDA NRCS, this earth dam stands at a height of 31 feet and has a length of 550 feet, creating a reservoir with a storage capacity of 113 acre-feet. The dam is regulated by the Iowa DNR and is inspected regularly to ensure its safety and compliance with state regulations.

Cowles Dam is situated on TR-Marks Creek and serves as a vital water resource for the surrounding area, providing water for fire protection, stock, and recreational use. With a surface area of 8.3 acres and a drainage area of 0.25 square miles, the dam plays a crucial role in managing water flow and supporting the local ecosystem. Despite its low hazard potential, the dam is categorized as having a moderate risk level, indicating the importance of ongoing monitoring and risk management measures.

While the condition assessment of Cowles Dam is currently listed as "Not Rated," its risk assessment suggests a need for proactive measures to address potential hazards. As a key component of the water infrastructure in the region, the dam's operation and maintenance are essential for ensuring water security and environmental sustainability. Climate and water resource enthusiasts can appreciate the role of Cowles Dam in supporting the community and protecting the local ecosystem amid changing environmental conditions.