Bipartisan support and the president’s signature have opened up way more than $19 billion in assistance for regions hit hard by natural disasters. Now we have the opportunity to go beyond simply rebuilding what was lost to learning important lessons about how to construct a more resilient infrastructure for the future.
This month it is the Arkansas River that is wiping out businesses and homes in Oklahoma. A few weeks ago, Houston was flooded, less than two years after being hit by Hurricane Harvey. And in California, the people of fire-stricken Paradise are figuring out how, and perhaps whether, to rebuild their community literally from the ground up.
Even those who deny climate change cannot deny the damage caused by major hurricanes on the Gulf Coast and in Puerto Rico. They cannot ignore the repeated flooding of the Mississippi and Missouri Rivers, nuisance floods on numerous smaller waterways across the nation and on our east and Gulf coasts, landslides associated with heavy rainfall, and massive forest fires.
These unexpected events have now become expected. What’s not known is where and when they will hit next. When they do, the damage can be immense, and the new priority it has brought to the debate about the nation’s infrastructure is resilience — the ability to resist damage, and to come back quickly when damage occurs.
Restoring public and private infrastructure is costly — the National Oceanic and Atmospheric Agency documents the steady increase in annual billion dollar (CPI-adjusted) natural disasters. That’s up by about a factor of five over the past 30 years and approaching $400 billion each year. There are also disruptions to daily lives and businesses present additional large, widely distributed, and unaccounted costs. This includes farmers who cannot get to their fields or markets, lost days of work and school, and foregone sales.
As decisions are made about restoring the nation’s aging infrastructure, we need to make resilience a priority. The key questions are: What are the practical things that can be done to ensure that the new infrastructure will not be wiped out by the next severe weather event or flash fire? When disruptions do occur, what can be done to make sure infrastructure will be up and running again in hours or days, not weeks and months?
The regions that will be on the receiving end of the newly approved disaster relief are having this conversation in real time. For them, and those who are nagged by the feeling that they could easily be next, here are ways resilience can be built into a renewed American infrastructure.
- Hardening: Infrastructure must be designed to resist damage from natural and accidental events. Hardening means measures such as reinforcing dams and levees that protect people and property, securing the power grid from wind and water damage, and putting tornado shelters in schools and other public buildings.
- Durable design: Knowing that the floods are coming and sea levels are rising, durable design means raising bridges now touched by higher flood waters. This means boosting the habitable parts of structures to let waters pass under and through, as in New Orleans after Katrina and Staten Island after Superstorm Sandy. It also means designing pavements that can withstand weeks-long inundation.
- Smart location: The places where structures are built — or rebuilt — should be driven by data and experience, giving people and businesses both the information and incentives to move away from flood plains, eroding coast lines, and repeated fire hazards to dodge repeated assaults from nature. After Hurricane Harvey, the people of Houston approved a $2.5 billion bond issue for flood control measures that includes an enormous home buyout program.
- Redundancy: Resilience can come through redundant facilities — particularly for network systems like water supply lines, bridges and tunnels — that provide multiple paths for meeting essential service needs when a disruption occurs, as well as the capacity to take a facility out of service for rehabilitation while continuing business as usual.
Redundancy also can come in the form of factorable designs like microgrids that contribute to network electric power needs but can function independently when a disruption occurs. What a different story it would have been in Puerto Rico if the island had been powered by a network of interconnected microgrids fed by renewable energy sources when the island’s electric infrastructure was blown out by Hurricane Maria.
Delivering resilient infrastructure calls for new ways of thinking about risk management. The Dutch, for example, with a millennium of experience fighting water, have backed away from building ever-higher levees. These levees not only make matters worse for those living downstream but can also amplify damage when they fail, as we saw recently along the Mississippi and so dramatically after Katrina.
Instead, Rijkswaterstaat, the Netherlands Ministry of Infrastructure and Water Management, is making room for the rivers to flood, setting aside land, relocating people, and building infrastructure that accommodates temporary flood water storage. The Dutch are taking a more serious stand against risk by preparing for flood magnitudes that happen only once in 10,000 years, in contrast with U.S. standard of once in 100 years.
Thinking in terms of resilience will mean not just rebuilding, but assuring a more secure future by adopting new designs. It also means adopting strategies that learn from and respond to a changing pattern of risks, no matter the source.
Joseph L. Schofer is a professor of civil and environmental engineering at Northwestern University. He is also the host of “The Infrastructure Show,” a podcast that explores many aspects of the nation’s infrastructure system and the threats it faces.