It is true that inflation-adjusted total flood costs in the United States on average rose from $3.5 billion in 1903 to $12.8 billion in 2018. By 2018, the annual cost of US flooding was 370 percent of what it used to be in 1903. But the number of housing units in the US has increased much, much more: by 2017, there were 750 percent as many housing units to be damaged as there had been in 1903.
