High-resolution hydrographic mapping, which provides essential data for flood mitigation and planning, is being completed on thirteen 12-digit hydrologic units near Sioux Falls, South Dakota. A lidar-derived digital elevation model is being processed using selective drainage methods to hydro-enforce culvert locations into the modeled drainage network. While some culverts had been inventoried prior to this study, many additional culverts were inventoried as a part of this study, and still more culvert locations are being identified using selective drainage processing. Cooperating agencies will ground-truth the culvert locations not yet inventoried, and will field verify any locations where the synthetic drainage network appears to depart from existing flowlines in the National Hydrography Dataset. The lidar-derived watershed boundaries and surface drainage patterns will provide resource managers and urban planners with better detail and a more current picture of hydrographic features in the study area.
Location of the study area.