ArcGIS Hydrology: Watershed Area, Longest Flow Path & WGS1984 Troubleshooting

Building on basic hydrology tools, this tutorial dives deeper into watershed delineation, calculating the exact watershed area, and finding the longest flow path in ArcGIS. This time, we tackle a very common real world workflow by extracting a pour point coordinate directly from Google Earth, formatting it in Excel, and importing it as a CSV file. We also strictly use the WGS1984 coordinate system throughout the process so we can identify and troubleshoot the specific projection errors that occur when calculating area and length in a geographic coordinate system rather than a projected one. What You Will Learn: Extracting precise pour point coordinates using Google Earth Formatting data in Excel and importing CSV files into ArcMap Complete watershed delineation using DEM data Calculating the total watershed area accurately Generating the longest flow path for your catchment Troubleshooting WGS1984 projection issues, specifically fixing unit errors when measuring area and flow length