Harvey has lessons about flood risk and preparation

From afar, the statistics, images and stories flowing out of southeastern Texas are difficult to comprehend. Hurricane Harvey exploded from a cluster of rainstorms to a monstrous Category 4 hurricane in less than 72 hours. Biblical amounts of water, hundreds of thousands of lives uprooted, the immense challenge ahead to rebuild the region — it is easy to feel overwhelmed and to tune out, especially given all the other events and issues that cry out every news cycle for our attention.

Sending the folks in Texas our thoughts as well as any forms of assistance we can muster is one way to respond to the crisis. The Red Cross, Salvation Army and Catholic Charities USA are channels for donating money, blood or supplies to the response effort. An additional way to respond to the flooding in Texas is to think critically about how we prepare for floods as communities and as a nation. It may be weeks before a preliminary analysis of the rainfall and storm surge is available, and deeper analyses of the preparations and response will take much longer. Perhaps no community can ever be prepared to receive a full year’s worth of rain in less than a week, as some Texans just experienced. But certainly we should question whether we are preparing our communities enough.

Most communities in the U.S. prepare for floods that have a 1 percent chance of occurring in any year. Misleadingly called the “100-year flood,” this is the minimum level of protection recommended by the Federal Emergency Management Agency (FEMA). While a 1 percent chance sounds small, there have been dozens of much larger floods around the country in recent years, some with odds smaller than 1-in-500 or even 1-in-1,000. The list includes South Carolina in 2015; West Virginia in 2016; Ellicott City, Md., in 2016; Louisiana in 2015 and 2016; and Texas in 2015 and 2016. While the odds of these larger floods are undoubtedly quite small, the nation sees several each year, and they have catastrophic consequences for the communities they strike.

Given the additional cost of protecting against bigger floods, what is an adequate level of protection? In the Netherlands, where much of the country is below sea level, large floods historically have devastated the Dutch economy. In light of nation-crippling consequences, the country is committed to protecting against the 1-in-10,000 chance flood.

In the U.S., that extreme level of protection may be unnecessary for all but a handful of the most critical and consequential cases (nuclear facilities, for example). However, the 1-in-100 chance standard is increasingly exposed as inadequate. Under the current standard, a home in the regulatory floodplain has a 26 percent chance of flooding during a 30-year mortgage. For many Americans, a home is their largest investment, and those odds are not good.

With this in mind, communities like Cedar Falls, Iowa, have raised their protection level to the 1-in-500 annual chance flood. Since FEMA already includes this scenario on flood maps, a straightforward modification to local codes is all it takes to adopt a higher standard of protection. Indeed, the Federal Flood Risk Management Standard was updated to this higher standard in 2015, requiring taxpayer-funded projects to be built to withstand the 1-in-500 chance flood. The White House repealed that provision just 10 days before Hurricane Harvey came ashore.

Adopting stronger flood protection standards is a local government’s decision. However, a national opportunity to discuss higher protection is at hand. The National Flood Insurance Program (NFIP) is due for reauthorization by Congress at the end of September. The NFIP is notoriously in debt by $24 billion dollars — a hole that Harvey is sure to deepen. This debt is in part because the NFIP is built around the 1 percent annual chance flood and fails to adequately anticipate very-low-probability-but-extremely-high-consequence outliers like Harvey, Katrina and Sandy (the debt also exists in part because the premiums charged to policyholders fall below what their actuarial risk would require).

As the future of the NFIP is debated in Congress this fall, prudence demands that our thinking about flood risk should evolve along with the risk itself. Greater urban development, more extreme and intense rainstorms, and rising sea levels combine to create a situation where the actual risk of flooding is far ahead of our systems for reducing risk. We need to recalibrate our risk management by planning for more of the outliers.

A responsible first step is local, state and national commitments to protecting communities like Rockport, Texas and Ellicott City against the 1-in-500 annual chance flood. If the residents of southeast Texas have paid the price in this round, the rest of us surely owe it to them to learn this lesson about risk and responsible preparation.

Brian Ambrette is the coastal resilience program manager at the Eastern Shore Land Conservancy. His email is bambrette@eslc.org.

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