AnsweredAssumed Answered

Flow Direction tool produces erroneous lines in output raster

Question asked by geonetadmin on Apr 19, 2013
Latest reply on Apr 22, 2013 by erice-esristaff
Original User: jonathankoehler

I am running the Flow Direction tool on a seamless bare-earth NED raster elevation grid.  The tool runs fine, but the output raster has a series of horizontal and vertical lines - like a grid - that contain erroneous flow directions, and therefore make the layer useless for generating watersheds.  Attached are a couple of picture of what the output rasters look like - one is from a 1m DEM and the other is from a 10m.  These lines are not visible in the raw DEM file, so it appears that something about the Flow Direction tool brings them out or creates them. 

I have tried running Flow Direction with several DEM resolutions including 10m, 30m, and 1m LiDAR with the same results.  I have also tried running it with and without first using the Fill tool to clean it up - it doesn't seem to make any difference.

I'm using using ArcGIS Desktop 10 SP 5, ArcInfo license.  Any help would be greatly appreciated.  Thanks,