Process_Description:
Prior to 6/1/99, processing information is directly from ICBEMP. The base layer used was the 1993 version of the USGS Water Resource Division 1:100,000 streams digital line graph (DLG), obtained through the EPA Seattle office. Ten tiles were replaced with updated tiles from the Bonneville Power Administration (BPA), also obtained through the EPA Seattle office. Updates were completed by the WA Dept of Energy and the OR State Service Center for GIS, under contract with BPA. The updated tiles were: f17010308, f17020006, f17020007, f17020008, f17030001, f17030003, f17060106, f17060109, f17070106, and f17010216. Several modifications were made to the tiles, which included: renaming streams to eliminate duplicate names, naming unnamed streams (if they had associated stream survey data and were identifiable on a map), reprojecting the tiles to NW Albers, ARC flipping to represent stream flow direction correctly in order to assign Strahler order, route development (based on stream names), addition of Strahler order to the .aat and addition of HUCID to the streams.ratname INFO file (in order to link to stream survey data), and remeasuring major streams for streams crossing tiles (due to makeroute utility starting all streams within a tile at 0).
Data was downloaded from the ICBEMP website and projected from NW Albers to Transverse Mercator (State Plane Coordinate System) NAD 83. As of 6/1/99, data was imported into ArcInfo (ShapeArc), topology built (Arc Clean), and exported as interchange file (e00).