Across the country, flooding is a growing risk — both in how high waters surge, and as a new hazard in areas previously unlikely to be inundated. As storms arrive more frequently, flood insurance and disaster relief programs themselves are now failing.

Yet most homeowner policies do not cover flood damage, requiring families to acquire an entirely different, second insurance plan. Most of these are purchased through a government-backed program called National Flood Insurance Program, or NFIP. “Private markets pulled back from flood decades ago,” Kousky explained.

But as prices surge, hundreds of thousands of people have dropped their flood insurance, growing the burden on federal disaster assistance and straining its already stretched budgets. Many are falling through the cracks. The lack of clarity on what assistance will be available from insurance or disaster relief prevents many families from receiving the aid they need. After New England’s flooding this summer, for instance, residents who received money from the Federal Emergency Management Agency, or FEMA, in 2011 during the last once-in-a-century storm are only just realizing unmet insurance requirements mean they are ineligible for further emergency assistance.

The majority of natural disasters in the United States already involve flooding. It’s a problem that will get worse with sea-level rise and more intense rain events. By 2050, coastlines will see a national average of 45 to 85 days per year of high-tide flooding. Meanwhile inland, rivers and streams are spilling over their banks more frequently, a type of flooding projected to increase by as much as 30 percent as temperatures rise. Extreme rain is also becoming more common: Peer-reviewed data from the First Street Foundation, a climate research nonprofit, suggests about 20 percent of the country will now see a “once in a century” rainfall about every 25 years.

Read the full article about climate change and insurance markets by Lois Parshley at Grist.