The USGS is testing a new online interactive mapping tool to display flood inundation status cross the US. On first look it appears to be a great tool for visualizing what portions of the country are troubled by flooding. The green balls represent areas where NO flood is occurring. The black triangles indicate areas under flood watch.
Clicking on a site such as i did in northeast Arizona in the image below, brings up an info box that includes a link to the original data source.