Willow Cr-Park R Detdam#1 is a vital earth dam located in St. Thomas, North Dakota, designed by the USDA NRCS and completed in 1968 for the primary purpose of flood risk reduction along Willow Creek. This dam stands at a height of 23.8 feet with a structural height of 28 feet, and a length of 8280 feet, providing storage of up to 3219 acre-feet of water and covering a surface area of 62.3 acres. The dam is state-regulated by the NDSWC and is classified as having a significant hazard potential, with a moderate risk assessment rating.

The dam features an uncontrolled spillway with a width of 250 feet, and while it has not been rated for its condition, it is inspected regularly by the state, with the last inspection conducted in October 2017. The dam has no outlet gates and serves as a critical infrastructure for flood risk management in the region, being a key component of the local government's water resource management strategy. Enthusiasts of water resources and climate will appreciate the engineering and design details of Willow Cr-Park R Detdam#1, as well as its role in protecting the surrounding area from potential flooding events.