Mc Donald Subwatershed Site 1 in Woodbury, Iowa is a local government-owned dam designed by USDA NRCS for recreation and flood risk reduction purposes. Completed in 1985, this earth-type dam stands at 35 feet tall with a length of 354 feet, providing storage of 220 acre-feet and covering a surface area of 12.3 acres. Situated along the TR-Little Sioux River, this dam is regulated by the Iowa DNR and is under state jurisdiction, with permitting, inspection, and enforcement in place to ensure its safety and functionality.

Although the dam has a low hazard potential and is currently rated as "Not Rated" in terms of condition assessment, the risk assessment categorizes it as moderate. The dam's spillway type is uncontrolled, and it has not undergone any modifications in recent years. While the emergency action plan (EAP) status and risk management measures are currently not available, the dam is not under the jurisdiction of the US Army Corps of Engineers. With its strategic location and purposeful design, Mc Donald Subwatershed Site 1 serves as an essential infrastructure for water resource management and climate resilience in the region, contributing to the overall conservation efforts in Iowa.