Observed Change in Very Heavy Precipitation

Percent changes in the amount of precipitation falling in very heavy events (the heaviest 1%) from 1958 to 2012 for each region. There is a clear national trend toward a greater amount of precipitation being concentrated in very heavy events, particularly in the Northeast and Midwest. (Figure source: updated from Karl et al. 2009c ).
According to Rob Moore, a water and climate expert at the Natural Resources Defense Council, 25 percent of flood damages in the country stem from heavy rainfall overwhelming stormwater systems, rather than flooding we normally associate with rivers rising over their banks.
Source: National Climate Assessment
URL:     http://s3.amazonaws.com/nca2014/high/NCA3_Climate_Change_Impacts_in_the_United%20States_HighRes.pdf?