100 year floods seem to occur about every 3 to 5 years
The Neuse and Pamlico rivers, along with everything that feeds into them, have risen and will continue to rise substantially due to Florence.
The has monitoring points for those concerned about river and stream levels, and the also provides graphs using data from the USGS. The USGS also has some live stream web cams, like this one in , that can be helpful when trying to gauge conditions at times like this when the Carolinas are experiencing widespread flooding.