"Across much of the United States, the flood risk is far greater than
government estimates show, new calculations suggest, exposing millions
of people to a hidden threat — and one that will only grow as climate
change worsens."
"That new calculation, which takes into account sea-level rise, rainfall
and flooding along smaller creeks not mapped federally, estimates that
14.6 million properties are at risk from what experts call a 100-year
flood, far more than the 8.7 million properties shown on federal
government flood maps. A 100-year flood is one with a 1 percent chance
of striking in any given year."
"Federal flood maps, managed by the Federal Emergency Management Agency,
have long drawn concerns that they underestimate flood risk. Part of
the problem is keeping the maps up to date, which is not only costly and
labor intensive, but further complicated as climate change has worsened
the dangers."
"In addition, FEMA’s maps aren’t designed to account for flooding caused by intense rainfall, a growing problem as the atmosphere warms."
