United States Department of Agriculture and Indiana Geological Survey
The following is extracted from USDA, NRCS metadata -- "This data set is a complete digital hydrologic unit boundary layer to the Watershed (10-digit) 5th level for the NRCS business areas in and around the state of Indiana. This data set consists of geo-referenced digital data and associated attributes created in accordance with the "Federal Guidelines, Requirements, and Procedures for the National Watershed Boundary data set; Chapter 3 of Section A, Federal Standards, Book 11, Collection and Delineation of Spatial Data; Techniques and Methods 11-A3" (04/01/2009). http://www.ncgc.nrcs.usda.gov/products/data sets/watershed/index.html . Polygons are attributed with hydrologic unit codes for 4th level sub-basins, 5th level watersheds, name, size, downstream hydrologic unit, type of watershed, noncontributing areas and flow modification."