Hi Stacie,
Thanks for taking the time to go through all those options for me, it helps a lot.
While I try to mitigate the issue, I just wanted to ask how far it would be acceptable to have some of these weird flow artifacts in one’s final model, seeing as it is a common problem in flat areas? I’ll certainly look into the options you suggest, but also want to make sure I don’t expend excessive time and effort on completely eliminating the issue if it is something that is unavoidable and/or acceptable to a certain extent, given the limitations of the algorithms.
Edit: I also just discovered the Fill tool in ArcGIS has actually completely flattened out the relief in some of the valley floors! I expect using the original DEM will help significantly. I understand filling the DEM is recommended, so I’m rather surprised it messed up the valley floors so much in this instance.