Hi Christine- thanks for your reply, I just returned from the dev summit or I would have gotten back to you sooner. Um, I'm not certain I was clear with my request. Do you mean to say 'tables that contain the unique HydroID' rather than 'Unique ID tables'? I ask because I'm not familiar with 'Unique ID tables' as part of the full ArcHydro schema; I've never seen those objects. Regardless, we'll test out populating HydroIDs on those objects that the tools require once we version the schema-
Thanks
David