National Hydrography Dataset NHDFlowline layer with a spatial representation of designated water uses defined in Title 25 Environmental Protection, Department of Environmental Protection, Chapter 93, Water Quality Standards. The Pennsylvania Code just cited provides a list of all streams or watersheds (basins) in the state along with their associated designated water uses. This GIS layer displays these uses spatially on an interactive stream map. Public users can drill down to locations on the map to view and map the designated uses of the water bodies of interest. The layer can also be used in conjunction with other spatially referenced data for spatial analyses.