Hydrology in ArcGIS Pro, Lab Exercise 3: Filling Sinks in a DEM

In Lab Exercise 2 we saw what happens when you fail to fill your DEM before you generate your flow direction raster, and how that caused your watershed analysis to fail. The watershed algorithm starts at your pour point (which is the Picture Canyon Preserve in these labs), and works upstream until it can't find any more upstream regions. If there is a low point in the DEM where all the neighboring cells are higher than that point (and there almost always is), then the algorithm stops at that low point. These low points are called sinks in the DEM.

So we just need to fill these sinks in the DEM before calculating the Flow Direction raster. This lab exercise will show you how to do that, using the Fill tool.

Lab Exercises:

Extra Materials: