U.S. Flood Risk Higher Than Thought

From the Homeland Security Newswire: Flood risk for Americans is greatly underestimated,

A new study has found that forty-one million Americans are at risk from flooding rivers, which is more than three times the current estimate—based on regulatory flood maps—of thirteen million people. The study is based on a new high-resolution model that maps flood risk across the entire continental United States, whereas the existing regulatory flood maps produced by the Federal Emergency Management Agency (FEMA) cover about 60 percent of the continental United States. Avoiding future losses is particularly important as average flood losses in the United States have increased steadily to nearly $10 billion annually.

Here is another take on the topic from Vox: We’ve radically underestimated how vulnerable Americans are to flooding. New research claims that official estimates lowballed the risk by, uh, about a factor of three.

Riverine Flooding On the Rise Worldwide

River flood risks increase around the globe under future warming.

“More than half of the United States must at least double their protection level within the next two decades if they want to avoid a dramatic increase in river flood risks,” says lead-author Sven Willner from the Potsdam Institute for Climate Impact Research (PIK). Without additional adaptation measures – such as enhancing dykes, improved river management, increasing building standards, or relocating settlements – the number of people affected by the worst 10 percent of all river flooding events will increase in many places …..”

“Lessons From Hurricane Harvey: Houston’s Struggle Is America’s Tale”

The Diva has been contemplating the concept of resilience, as described in the document Disaster Resilience; A National Imperative, published by the National Academy of Sciences in 2012. Reviewing it against the present setting of disaster recovery efforts in Houston, TX, the State of FL, and all of Puerto Rico has raised many questions.

Reading this powerful article in the N.Y. Times suggests to me that it is time to review current thinking about resilience and about emergency management in general. See: Lessons From Hurricane Harvey: Houston’s Struggle Is America’s TaleSome key excerpts:

For years, the local authorities turned a blind eye to runaway development. Thousands of homes have been built next to, and even inside, the boundaries of the two big reservoirs devised by the Army Corps of Engineers in the 1940s after devastating floods. Back then, Houston was 20 miles downstream, its population 400,000. Today, these reservoirs are smack in the middle of an urban agglomeration of six million.

Unfortunately, nature always gets the last word. Houston’s growth contributed to the misery Harvey unleashed. The very forces that pushed the city forward are threatening its way of life.

Sprawl is only part of the story. Houston is also built on an upbeat, pro-business strategy of low taxes and little government. Many Texans regard this as the key to prosperity, an antidote to Washington. It encapsulates a potent vision of an unfettered America.

After every natural calamity, American politicians make big promises. They say: We will rebuild. We will not be defeated. Never again will we be caught unprepared.
But they rarely tackle the toughest obstacles. The hard truth, scientists say, is that climate change will increasingly require moving — not just rebuilding — entire neighborhoods, reshaping cities, even abandoning coastlines.

We need a whole new structure of governance,” he insisted. “We’ve built in watersheds, paved roads and highways because we don’t have mass transit.
“Inevitably, it all catches up with us,” the judge said. “Mother Nature has a long memory.”

See also this posting dated Sept. 7th: What H. Harvey Says about Risk, Climate, and Resilience.