High-Resolution Hydrographic Mapping on a portion of the Big Sioux River Basin in Southeast South Dakota, 2016

A High-Resolution Hydrographic Mapping effort was completed for thirteen 12-digit hydrologic units in the Big Sioux River Basin near Sioux Falls in southeastern South Dakota. A digital elevation model based on light detection and ranging (lidar) data was prepared from four sources. Known culverts were hydro-enforced into the elevation model, and selective drainage techniques were utilized within geographic information systems software to identify additional locations where bridges or culverts needed to be hydro-enforced. These potential locations were given a preliminary screening using aerial imagery, and likely locations were further screened using high-resolution oblique aerial imagery or with site visits. Locations with confirmed culverts were also hydro-enforced. The raw and hydro-enforced elevation models were used to generate flow derivative layers. The elevation models, flow derivative layers, and culvert layer are included as geospatial data layers within this data release. This study was completed by the U.S. Geological Survey, Dakota Water Science Center in cooperation with the City of Sioux Falls, the City of Harrisburg, Lincoln County, the South Dakota Department of Transportation, East Dakota Water Development District, and the Mid-America GIS Consortium.