How to create a directional and accumulation raster using a 5m DEM?

[tzz_12]

Hi Everyone, 

I need to create watersheds for the central valley area of CA. When I tried to create the directional and accumulation rasters for the 5 meter DEM that covers the entire CA, the tools keeps clashing. Based on my research, it's due to the raster being too big for the tool to handle. What is the best approach to create the watersheds using the 5 m DEM? Should I clip the DEM into smaller sections, create the directional and accumulation rasters for each sections and merge them together? This seems like a very time-consuming method. If I need to do that, how small does the DEM have to be for the directional and accumulation tool to work properly?

Thanks for your help!

[Robert_LeClair]

A couple reasons why the GP tools to create flow accumulation and direction rasters fail are:

1. Insufficient memory on your PC.  Processing large datasets with high spatial resolution consumes a ton of memory.
2.  Hardware limitations - processing power of your PC's CPU and GPU.
3.  ArcGIS Pro has certain limitations when it comes to processing large datasets.  Likely you'd need to run the Resample or Aggrgate GP tools to change the cell size of your rasters. (i.e. lower spatial resolution)

I would recommend you test workflows for smaller areas of interest to see if the GP tools succeed for fail.