Lum Hollow Subwatershed 9-5186 is a small earth dam located in Woodbury County, Iowa, near the city of Turin. Built in 1959 by the USDA NRCS, this dam serves multiple purposes including fire protection, stock, small fish pond, and flood risk reduction. With a height of 40 feet and a storage capacity of 51 acre-feet, the dam covers a drainage area of 0.34 square miles and has a surface area of 1.7 acres.

Managed by the Iowa DNR, Lum Hollow Subwatershed 9-5186 is classified as having a low hazard potential and a moderate risk assessment. The dam is uncontrolled with an unmeasured spillway, and its condition assessment is currently not rated. Despite its age, the dam remains structurally sound and continues to provide valuable water resource management services to the surrounding area.

As a water resource and climate enthusiast, Lum Hollow Subwatershed 9-5186 presents an intriguing case study in sustainable water management and infrastructure resilience. With its long history of service and multiple functions, this dam stands as a testament to the importance of proper maintenance and regulation in ensuring the safety and effectiveness of water retention structures in a changing climate.