A national map of the flooding status at stream and river gages is available from the National Weather Service/Advanced Hydrologic Prediction Service, online at http://water.weather.gov/ahps/. The gage locations are color coded from “no flooding” (below flood stage) to “major flooding.” From the national map, one can zoom in to see a particular state or locality, and you can click on individual gage markers to get detailed information.
Maps of stream and river levels compared to historical records are available from the U.S. Geological Survey (USGS), online at http://waterdata.usgs.gov/nwis/rt. Gaging station locations across the country on these maps are color-coded to indicate how current flows compare to historical normal values at a given gage location. You can see the comparison for current (real-time) flows or for flows averaged over various recent periods, ranging from the previous day to the previous month. The real-time Virginia map is available online at http://waterwatch.usgs.gov/?m=real&r=va.
The USGS stream/river levels map also allows users to access more detailed information for individual gage locations. An April 14, 2015, example from Virginia is shown below.