We've been doing some work to organize data from past-flood events and prepare for future events.
First, we now have a "Flood" folder on the GIS Hub's REST page. The data in this folder can be used in ArcGIS Desktop. If you have a requirement to have these data available in other web service formats, please let us know. We plan to post past and new flood data here as it becomes available and/or is needed. Eventually, older datasets may be removed.
Second, we've taken some of this data and created applications that allow side-by-side viewing of rivers impacted by flooding. The Missouri River flood application shows the Missouri River cooridor before, during, and after the 2011 flooding. The Mouse River flood application shows the Mouse (Souris) River corridor before and during the 2011 flooding. We plan to build similar applications for other areas as data become available.