Figure 5. Average annual flow per area (m3seconds(s)-1km-2 for selected river basins in Alaska, British Columbia, Washington, Oregon, California, and Idaho. Values were calculated as the average annual flow for each gauging station divided by the reported gauged area. Based on USGS streamflow data (Hydrosphere Data Products, Inc. 1993) and Inland Water Directorate streamflow data (Environment Canada 1991) (modified from Weitkamp et al. 1995).