Jdw Dam, located in Marengo, Iowa, was completed in 1970 by the USDA NRCS and serves multiple purposes including fire protection, stock, and small fish pond. With a height of 28 feet and a length of 355 feet, this earth dam has a storage capacity of 47 acre-feet and covers a surface area of 4.2 acres. The dam is state-regulated by the Iowa Department of Natural Resources and is inspected, permitted, and enforced by the state regularly.

Despite its low hazard potential, the dam's risk assessment is moderate, indicating a level 3 risk. The condition of the dam is currently not rated, as the last inspection took place in April 1977. Although the dam does not have an Emergency Action Plan (EAP) prepared or updated, it meets regulatory guidelines. With its location on the TR-Iowa River and under the jurisdiction of the Detroit District of the USACE, Jdw Dam is a crucial structure for water resource management in the area.

Overall, Jdw Dam is a vital asset for fire protection, stock, and small fish pond management in Marengo, Iowa. With its moderate risk assessment and low hazard potential, the dam plays a significant role in water resource management for the local community. As efforts continue to ensure the safety and regulatory compliance of the dam, it remains a key structure in the region for both water resource and climate enthusiasts to monitor and study.