Ryun Dam, located in Decatur County, Iowa, is a privately owned structure designed by the USDA NRCS for fire protection, stock, or as a small fish pond. Completed in 1994, the earth dam stands at a height of 28 feet and spans 414 feet in length, with a storage capacity of 73 acre-feet. The dam serves the primary purpose of fire protection and provides a surface area of 4.4 acres, with a drainage area of 0.23 square miles.

Managed by the Iowa Department of Natural Resources, Ryun Dam is regulated, permitted, inspected, and enforced by state authorities to ensure its safety and compliance with regulations. With a low hazard potential and a moderate risk assessment rating, the dam has not been rated for condition assessment, but meets guidelines for emergency action preparedness. Despite its uncontrolled spillway type, the dam poses minimal risk to its surrounding area and is considered a valuable resource for water conservation and management in the region.

For water resource and climate enthusiasts, Ryun Dam stands as a testament to sustainable water management practices. Its construction and design by the Natural Resources Conservation Service reflect a commitment to environmental stewardship and the protection of local ecosystems. As a vital component of the TR-Weldon River system, the dam contributes to the overall resilience of the watershed and ensures the availability of water for various uses, including fire protection and wildlife habitat. With ongoing state oversight and monitoring, Ryun Dam continues to play a critical role in maintaining the balance between human needs and environmental preservation in the region.