West Fork Big Creek Watershed Site B-39 is a low hazard potential earth dam located in Iowa, specifically in Decatur County. Completed in 2003, this dam serves the primary purpose of flood risk reduction along the TR-West Fork Big Creek. Managed by the Iowa Department of Natural Resources and designed by the USDA NRCS, this site spans 488 feet in length and stands at a height of 26 feet, with a maximum storage capacity of 90 acre-feet.

With a drainage area of 0.28 square miles and a surface area of 4.5 acres, this dam plays a crucial role in managing water flow and mitigating flood risks in the region. Despite being uncontrolled, the spillway of this dam is designed to handle potential overflow events. The risk assessment for this site is moderate, indicating a level of 3 out of 5 in terms of potential hazards. While the condition of the dam is currently not rated, regular inspections and enforcement measures are in place to ensure its structural integrity and effectiveness in flood risk reduction efforts.