Flood expectancy

There is a part of a book I am reading in these days that I consider a part of my thought, since it is well written I decided to add to my blog... :-)

"There are hundreds of thousands of culverts and small bridges over which roads and highways span channel of various size. If the capacity of such culverts were too small and many of them washed out, the expense would be very great. But if overdesign were the rule, money for construction would be needlessly spent." ... "It has been decided that culverts constructed with federal money would be designed to carry without failure a flood discharge with a recurrence interval of 50 years. Such decision places an enormous buden on hydrologists. They must develop simple but dependable methods to estimate flood discharge in ungaged areas in diverse climates and topography and for various basin sizes."
...
"A different kind of social cost results from the fact that people use flood-prone areas. Despite their knowledge of the importance of flood estimates, individuals continue to build on floodplains, encroaching on parts of rivers needed to carry rather ordinary discharges. The floodplain level is equaled or exceeded about one a year. So despite the vast sums spet on controlling floods, flood damage continues to rise year after year and is measured in bilions of dollars. Per-capita flood damage increased two and a half times in the United States between 1916 and 1985."

We should think about this...