I work at the Watershed scale, and as such I delineate a large number of individual basins. The Topaz created streamlines from a DEM for the most part are very good and known (digitized streamlines) agree well with it. But, for those instance where Topaz does not create a stream line where there is a known (and verified) streamline on the landscape, is there a way to adjust or add in a streamline so that I can delineate a particular basin? Typical of my work, I'm trying to delineate basins with outlets at road/stream intersections (culverts...). I've tried adjusting the threshold, hoping for the stream that I need to show up, but to no avail. What are my options in these situations?