Big Stone County adopted its first Comprehensive Local Water Plan in 1991. An update was completed according to State requirements in 1995 and most recently in 2013.One Watershed, One Plan (1W1P)
Minnesota has a long history of water management by local government. One Watershed, One Plan is rooted in this history and work initiated by the Local Government Water Roundtable (Association of Minnesota Counties, Minnesota Association of Watershed Districts, and Minnesota Association of Soil and Water Conservation Districts). In 2011 it recommended that the local governments charged with water management responsibility should organize and develop focused implementation plans based on watershed boundaries rather than county lines. The recommendation was followed by legislation that allows BWSR to adopt methods that allow local comprehensive plans, local water management plans, or watershed management plans to be replaced with one comprehensive watershed management plan. This legislation, and the associated BWSR program, are referred to as One Watershed, One Plan. Further Legislation was passed in 2015, defining purposes and outlining an additional structure for the program.
Big Stone County has three watersheds within the county. Most of the county resides in the Upper Minnesota River Watershed (75.34%). The Upper MN and Pomme de Terre River Watersheds both flow south eventually entering the Mississippi River. The Bois de Sioux/Mustinka River Watershed is in the northern part of the county and flows north eventually to the Red River.
Pomme de Terre's comprehensive plan through 1W1P plans to be finished by October 2018. The Upper Minnesota and Bois de Sioux started in 2018. It is about a 2-year process to create the comprehensive water plan.