Hoseck Detention No.1, also known as Loyal Hoseck Detention, is a private earth dam located in Winona, Minnesota, designed by the USDA NRCS and completed in 1978. The primary purpose of this dam is flood risk reduction, specifically for the Cedar Creek Offstream. Standing at a structural height of 36 feet and a length of 302 feet, this dam has a maximum storage capacity of 24 acre-feet and a normal storage capacity of 9 acre-feet, serving a drainage area of 0.47 square miles.

With a low hazard potential and a moderate risk assessment rating, Hoseck Detention No.1 is crucial in mitigating flood risks in the area. The dam features an uncontrolled spillway type with a width of 30 feet and outlet gates that are also uncontrolled. While the dam has not been rated for condition assessment, its strategic location and design contribute to its effectiveness in managing floodwaters and protecting the surrounding community. As an integral component of flood risk reduction efforts in the region, Hoseck Detention No.1 plays a vital role in safeguarding against potential water-related disasters.