Does the model boundary need to be placed far enough from the area of interest to ensure errors are not introduced for all boundary conditions in steady and unsteady flow models (I realize this doesn’t apply to some of the BCs in unsteady flow models)? There is information that this is the case for the Normal and Critical depth boundary conditions but I can’t seem to find any information for some of the other BCs. I am mostly interested in this with respect to the Known WS, Rating Curve, and Hydrograph BCs. If so, can anyone provide a source that explains the reason for this?