The Water Permits Unit oversees the administration of the Public Waters Work Permit Program. This program, begun in 1937, regulates water development activities below the ordinary high water level (OHWL) in public waters and public waters wetlands. These areas are identified on maps available for viewing at numerous locations, including this web page, or they can be purchased through Minnesota's Bookstore. Examples of development activities addressed by this program include filling, excavation, shore protection, bridges and culverts, structures, docks, marinas, water level controls, dredging, and dams. Field staff serve as the primary contacts for this program, and most activities can be authorized at either DNR Waters area or regional offices. The program staff in St. Paul provides policy guidance, program coordination with other water and wetland resource protection programs, permit decision appeal processing, and permit data management services.