I've been using tapered polygons to taper the upstream portion of streams since ArcGIS 9.2 The tapered polygon representations I made in map projects from earlier versions of ArcGIS still work in ArcDesktop 10.1. Now you don't have to download the taper.dll and install it yourself. It's built into 10.1. I tried to create a tapered polygon representation in a stream FC in a WRIA I hadn't mapped before (same data source), and it mostly worked, except this time the direction of the taper is reversed, i.e. with this new representation, streams are thick in the headwaters and taper thinner to the mouth. I don't remember having to set direction back in 9.2. What am I supposed to do?
Last night I was thinking that perhaps the routes in WRIA 29 Fishhydro that I got a few years ago are flipped relative to their orientation in WRIA 30 that I've had since 2003. But it turns out that's not the problem (see the black arrows on each.) The reversed taper in WRIA 29 sure makes the stream network look goofy.