Just FYI for other projects; OpenLayers has an SOS client that you can use to construct these kinds of requests. Unfortunately, you can't use it on this project without a lot of work -- the zoom-sensitive flowline and gage visualization is tied to a particular version of OpenLayers, and the SOS client was not in OpenLayers at that time. Nevertheless, it's good to be aware of the OpenLayers SOS client for the future.