My goal was to animate the water surge down the river. The graphs I'd been seeing just were not giving the information I wanted. I was certain I could get live data from river gauges. The trick was finding out who had it, the current river levels as well as archived levels.
I currently have an automated script in place pulling river level data from weather.gov and writing it to my database. This page reads from that database and creates the graph I wanted. I chose to show river miles on the x-axis and water level over flood stage on the y-axis. (I have yet to find reliable data on the levee heights near the gauges, so what I show is compiled from multiple sources. Also note that there are sometimes no levee, an outer and inner levee, different sized levees on either bank, varying levee height up- and downriver, and flood gates.)
Data source: weather.gov