Floods in places that have never had floodplain maps are latest evidence of how far FEMA's mapping needs to go

Recent floods in Northern Michigan surprised residents who didn't think they were at risk and didn't have insurance though rainfall amounts had been rising for many years. That's the latest example of outdated floodplain mapping by the Federal Emergency Management Agency, report Tammy Webber and M.C. Wildeman of The Associated Press.

"The federal government's mapping method is arguably outdated and does not account for actual risks as climate change increases the odds of more extreme weather," AP reports. FEMA "develops and updates maps that determine who's in a flood plain and must buy insurance, and to help communities plan. But it hasn’t developed maps in many less-populated areas, including some Michigan counties that experienced unprecedented flooding. . . . 

"Another issue: FEMA’s maps are based on risks of rivers, streams and other waterways overflowing their banks. But they don’t account for flooding caused strictly from increasingly heavy rainfall that overwhelms stormwater infrastructure in urban areas and inundates rural towns where there's nowhere for the water to go. First Street, a company that researches the financial implications of climate change, found more than twice the number of properties at significant flood risk nationwide after incorporating that rainfall data into its own models and by mapping the whole country, including smaller streams that FEMA does not."

FEMA, whose mapping has been criticized for years, wouldn't give AP an interview or respond to questions about whether it's updating its mapping methods and if this year’s flooding adds urgency to mapping less-populated areas, instead issuing a statement saying that 95% of the U.S. population lives in areas with floodplain maps, which are “snapshots in time.”

Chad Berginnis, executive director of the Association of State Floodplain Managers, said FEMA has made little progress creating new maps in rural areas where development could occur, despite a 2012 congressional mandate. He said the agency has prioritized places with the greatest population and risk, while leaving "about two-thirds of the country’s streams, rivers and coastlines unmapped," AP reports. "Some of those areas are unpopulated federal land that likely won't be mapped."

The state floodplain managers' group estimates that full mapping of the nation would cost $4 billion to $12 billion money FEMA has never had. The group worries that FEMA "could fall even further behind due to significant staffing losses under the Trump administration," AP reports.