|Stream miles not assessed in Federal Emergency Management Agency flood maps, by county (FEMA map; click on it to enlarge)|
The Federal Emergency Management Agency's National Flood Insurance Program creates and maintains maps meant to show which areas are prone to flooding, and also provides more than 96 percent of flood insurance nationwide. The maps help communities plan key infrastructure and shape public and private land use. They also inform insurance coverage: insurers require people who live in high-risk areas to buy flood insurance, Frank reports. Since homes in low-risk areas are not required to buy flood insurance, residents in increasingly flood-prone areas—many poor and rural—can't afford to rebuild after their homes are damaged or destroyed.
The maps are badly out of date, according to a recent study by the R Street Institute, a free-market think tank. One big reason: FEMA does not factor in global warming, which brings with it rising sea levels and increasingly frequent and powerful hurricanes, Frank reports.
The maps are incomplete, too, according to a recent report from the Association of State Floodplain Managers. Only a third of the nation's rivers and streams—1.1 million miles—and 46% of the nation's shoreline have flood-hazard information available. Mapping the remaining 2.3 million miles, most of which are in rural areas, and updating the current maps could cost anywhere from $3.2 billion to $11.8 billion. Maintaining and updating the maps would cost an estimated $107 million to $480 million annually, the report says.
The expense is worth it, according to the ASFM report. Since the NFIP was created in 1969, the nation has spent $10.6 billion in inflation-adjusted dollars on flood hazard mapping, preventing an estimated $22 billion in flood damages. Annual flood damages are increasing: they averaged $4 billion in the 1980's, but about $17 billion between 2010 and 2018 (that figure is somewhat skewed by the 2017 hurricane season, which had three of the top five costliest hurricanes on record).
The damages are likely under-reported, and don't include indirect losses from business closures, lost tax revenue, and the public health and mental health costs that often hit socially vulnerable communities harder, the report says.
There's another issue: NFIP must increasingly pay out for flood damages, so the program's costs are increasing, and FEMA may make it more like a private insurer, Jie Jenny Zou reports for Vox. That could spike insurance premiums and make it unaffordable for many to live in flood-prone areas.
Rural, lower-income residents in flood-prone areas could be in a peculiar bind: If FEMA updates flood maps to reflect the true risk, then such residents would be more likely to have flood insurance. But if NFIP rates become too high, they might not be able to afford to live there in the first place.