Not sure about that just yet. Hurricane Katrina probably still holds the record. We'll see what the numbers work out to, but things will need to settle down for a while before that can happen, I think.
Two personal friends of mine have already lost their homes to flooding. Others are stranded in the mountain areas and have been asked to decide if they want to evac out by air in the next two weeks, or remain there for the winter. Every single road accessing rural mountain communities has been compromised or severely damaged, and estimates are that repairs will take months. At least into next summer. To a guy like me who has traveled many of these roads in my Jeep while offroading up there, it's almost incomprehensible.
Edit: Here's a photo gallery to get ya started...
http://photos.denverpost.com/2013/09/14/photos-colorado-flood-damage-aerial-views/#1
54 minute aerial flood survey performed by our sheriff:
https://www.youtube.com/watch?v=W0d3j4zmnyY