I'm interested in creating a flood scenario for a rural county. I have DEM data for it, features for the 2 watersheds that cover the county, water features mapped, historic stream flow gauge data that I would like to use as a base for height, and was looking into using ArcHydro, but I can't quite figure it out. The documentation and tutorials for this type of thing is scattered, disorganized, and usually for out of date programs or, at best, the most recent ArcMap.
The intention of the map is to create some potential flood scenario based on stream depths measured by flow gauges, and use those to determine where flooding will likely make roads impassable. Any help would be appreciated.