Russ,
Though for a time the Durango water tank did have two spouts, only one was operational. The west facing spout was a movie prop, for a movie that I can't remember at the moment.
Also a note on the "wye".. Durango had a wye very early in its railroading history. Built shortly after the D&RG arrived and lasted a very short time. Taken out after the roundhouse and turntable were completed I believe. It was located just north of where the depot was to be built, with the east switch being about where the College Dr. crossing is now. The tail heading west. The track you mentioned being a leg of a wye is indeed the RGS connection but also lead to a balloon loop located below the yards, used mostly for turning the San Juan and early "Silverton" trains. The railroad also served a few customers down there, including a grain facility as well as a small Texaco storage facility.
The RGS Story Vol. XI has a lot of information on all the transformations the DGO yard had over the years, as well as many great photos. Some dating to before the depot and roundhouse were completed.
-Jon