Frd No 39, also known as Elk River WS Joint District No 47, is a flood risk reduction structure located in Elk Falls, Kansas. Built in 1977 by the USDA NRCS, this earth dam stands at 37 feet high and spans 1730 feet in length, with a capacity to store 632.35 acre-feet of water. The primary purpose of Frd No 39 is flood risk reduction, serving to protect the surrounding area from potential inundation by the Elk River.

Managed by the Kansas City District of the USACE, Frd No 39 is regulated by the Kansas Department of Agriculture and undergoes regular inspections to ensure its structural integrity and functionality. With a low hazard potential and a moderate risk assessment rating, this dam plays a crucial role in mitigating flood risks in the region. Although not currently rated in terms of condition assessment, Frd No 39 remains a key component of the local water resource infrastructure, safeguarding the community against potential flooding events.