What Happens When a Superstorm Hits D.C.?

A major hurricane could paralyze the government and jeopardize national security. Why is the capital so unprepared?

On August 25th, as Hurricane Harvey slammed into the Texas coast, Don Resio, a 70-year-old University of North Florida meteorologist and a leading expert in hurricane modeling, sat on his living-room couch with his wife, Kathryn, and their cat Marley, switching between the Weather Channel, MSNBC and CNN. "I knew it was going to be devastating," says Resio, but even he was surprised by the astounding 52 inches of rain recorded near Houston. Eleven days later, Hurricane Irma notched nearly unprecedented 185-miles-per-hour winds and then careened into Florida, ripping apart homes in the Keys and flooding downtown sections of Miami and Jacksonville, which is not far from Resio's home in the seaside community of Ponte Vedra. "It's not a good time," Resio says, "to be living near the coast." By the time Hurricane Jose moved within striking distance of half the Eastern Seaboard, American cities were seeming more and more like cursed metropolises on the banks of a warming, rising, increasingly wrathful ocean. The inevitable question becomes, where next? Resio and many other prominent experts believe one of the most vulnerable targets is a city rarely associated with hurricanes: Washington, D.C.

When the big storm hits D.C., the resulting disaster may not kill as many as Katrina, or flood as much physical real estate as Harvey, but the toll it takes on American institutions will be unfathomable. The storm will paralyze many of the agencies that operate and defend the nation, raising the specter of national-security threats. Imagine, says Gerald Galloway, a disaster and national-security expert at the University of Maryland who served 38 years in the military, "the world waking up some morning to see an aerial photograph of Washington, D.C., with everything from the Lincoln Memorial to the grounds of the Capitol under-water – that certainly does not speak well for the United States' preparedness."

The problem D.C. faces is largely one of geography. America's capital lies on the Potomac, an extremely powerful river that drops from 3,000-foot mountains to the Atlantic Ocean. And like all big rivers, the Potomac produces major floods. In September 1996, Jeff Kelble, the president of the Potomac Riverkeeper Network, watched a set of rapids known as Great Falls, located 17 miles outside D.C., rise in the wake of Hurricane Fran. "The river took houses off their foundations and rammed them into other houses," he says. Steep hills further downstream funnel the Potomac through Little Falls; according to Dean Naujoks, who works for Kelble, kayaking this stretch at flood stage "is like driving a car – you just start accelerating." From the falls, a flooded Potomac could sprint, in a muddy torrent of engorged fury, into D.C. Heavy rains over the headwaters of the Potomac released a deluge into the city 13 times between 1877 and 1996. The most notable floods were 1936, when the Potomac destroyed every single bridge but one along a 185-mile stretch, and 1942, when the river inundated the National Mall.

For scientists like Resio, a big concern is if a storm system in the mountains unfolds just before a major hurricane hits near the Outer Banks of North Carolina, then tracks inland, pulling a small mountain of water up the Chesapeake, then up the Potomac. This happened in the Chesapeake-Potomac Hurricane of 1933, which carried a deadly 11-foot storm surge; with Hurricane Hazel in 1954; Hurricane Connie in 1955; and Hurricane Isabel, a Category 2 storm that hit in 2003 with a nearly nine-foot surge that severed power at two of Maryland's largest sewage treatment plants, sending 96 million gallons of sewage flowing toward D.C. "Isabel is a reminder," wrote David L. Johnson, then assistant administrator for Weather Services, in a government assessment of the storm, "that if the impact of a Category 2 hurricane can be so extensive, then the impact of a major hurricane (Category 3 or higher) could be devastating."

Resio estimates that there are better-than-even odds that a one-two punch will descend on D.C. within the next 50 to 200 years. Though, "like with many situations," he says, "when it hits, people will say it was the perfect storm." Floodwater coming down the Potomac from the mountains would crash into water moving up the river with the storm surge from the ocean. This would set the stage for a dramatic physics experiment that even the world's most advanced meteorological computer models have had trouble simulating. "You end up with an interaction," says Ed Link, a former chief scientific adviser with the U.S. Army Corps of Engineers. "It is one plus one equals three."

Part of the problem is the city could already be flooded: Persistent rainfall over downtown D.C. could send sheets of water into the Federal Triangle, a wedge between Constitution and Pennsylvania Avenues containing seven crucial federal buildings, overwhelming the city's century-old sewer system and causing additional water to erupt out of storm drains. This happened in 2006, flooding the subbasement of the Internal Revenue Service headquarters with more than 20 feet of water and shutting down the Department of Justice, the Department of Commerce, the National Archives and the National Gallery of Art. Constitution Avenue, a vital D.C. artery built on the path of an old creek, flooded nearly nine feet deep with enough hydrostatic pressure to blast a hole through the foundation of EPA headquarters.

And if the river blasted through D.C.'s levee system, which has a slate of weak points, the entire area would essentially become part of the Potomac. According to a September 2016 report on sea-level rise by the Center for Climate and Security, a nonpartisan policy institute composed of security and military experts, "The continued strength of the U.S. depends, in large part, on having a clear-eyed assessment of risks and threats to the nation, and addressing them well before they manifest themselves." Washington, D.C., the capital of what is, for the time being, the richest and most powerful nation on Earth, is patently unprepared for its pending disaster.

Washington's defense begins with a little-known levee system. "There probably aren't 10 people in Washington," says Galloway, "who even know this levee exists." The Potomac Park Levee System is operated by the National Park Service and consists of an earthen berm that begins near the Lincoln Memorial and runs along the National Mall, passing just below the Vietnam Veterans Memorial and Constitution Gardens to the Washington Monument. At 17th Street, a busy thoroughfare that cuts right through the berm, a 140-foot-wide gap marks the levee system's greatest point of vulnerability. For the city to be protected, this must be manually patched.

In past floods, the hole in the system was filled with sandbags, a task that took 1,000 man-hours. In 2007, the Army Corps inspected the levee and gave the entire system a failing grade. This led FEMA to de-accredit it, meaning much of downtown D.C. was forced to pay into the National Flood Insurance Program. Three years ago, the U.S. Army Corps of Engineers unveiled a potential solution: a removable flood wall comprising eight steel posts and 27 aluminum panels that is stored in a maintenance yard a 30-minute drive from 17th Street.

Deploying the wall falls to the National Park Service's Division of Facility Management, whose workers have practiced setting up the barrier on just three occasions, though never at night, in the rain, or in the face of an actual hurricane or flood. The wall is stored in a National Park Service maintenance yard in northeast D.C., amid picnic tables and garbage bins. The steel posts and aluminum panels, along with several other items related to the wall's installation, lie strapped to the beds of two tractor-trailers, which National Park Service workers would steer down New York Avenue, around the Capitol and in toward 17th Street. A private company has been contracted by the park service to arrive on-site with a crane to lower the steel posts into deep slots. A strip of rubber would be inserted as a seal between the ground and wall. The panels would then be lowered into place between the posts. This work would likely take three hours, though there would still be one more step. Metal changes shape with temperature, and to leave room for these mutations, an inch-and-a-half-wide gap has been left between the posts and the panels. To keep water from coming through, says Jeff Gowen, acting chief of facility management at the National Park Service, a thick plastic sheet would have to be pulled over the entire length of the wall – a part of the process his team does not currently practice. To hold the sheet down, sandbags would be stacked along the bottom.

"Imagine the world waking up one day to everything from the Lincoln Memorial to the grounds of the Capitol underwater." 

According to Resio and other disaster experts, the list of things that could go wrong is long: Once on-site at 17th Street, one of the 27 aluminum panels could refuse to slide correctly into position; subsidence in the street could cause the slots to settle at different rates, and one or more of the posts could no longer fit; the plastic could rip. "Think about a car," says Resio. "Cars are very carefully engineered, but things still break. We don't build levee-protection systems better than cars."

And that's provided workers can even get the wall to 17th Street. A rain event that hits the region a few days prior to the approaching hurricane – what meteorologists call an antecedent storm – would mean the streets and subways could be flooded, preventing National Park Service staff from reaching the maintenance yard. Or, workers could make it to the yard but be unable to haul the wall's pieces to 17th Street because the route the tractor-trailers need to take is blocked by downed trees or power lines. Bureaucracy can be an issue too. "There are all sorts of interesting stories," says Galloway of urban levee systems, "where a flood comes and people can't find the parts."

The wall is not the only part of the Potomac Park Levee System with serious problems. A pretty patch of trees along the north side of the National Mall is growing around the earthen berm that serves as the city's critical levee, a potential violation of Army Corps of Engineers guidelines. "Vegetation on a levee creates what is called piping," says Resio. Roots of even a small tree or shrub can open a pathway for water under a levee. Piping occurred in New Orleans during Hurricane Katrina, helping cause a catastrophic failure of the city's levee system and spawning a flood that killed an estimated 700 people. In an e-mail, the Army Corps acknowledged that there are "smaller trees" located directly over the berm. Still, "at this time," says Jim Ludlam, a civil engineer with the Army Corps Baltimore District, which oversees D.C.'s levees, "Baltimore District feels the levee template meets its Vegetation Free Zone requirements."

There are yet more problems. Because it is a low-sloping earthen berm, rather than a steep wall, the levee could actually serve a bit like a ramp in a flood situation, says Resio. "One of the really nasty things about having that slope is the waves aren't forced to break," he says. "They can just run up and over." A mathematical formula dictates how far a breaking wave will travel up an incline. A two-foot wave on a low slope can reach a height of over three feet; a three-foot wave can stretch to five feet. The Potomac in a hurricane could easily have two-to-three-foot waves, meaning the levee, which is slated to protect the city against a Potomac flood that rises 19 feet above sea level, would actually only be capable of protecting the city against something more along the lines of a 15-foot flood.

There would also be debris in those waves, gigantic oak trees or one of the multi-ton sailboats docked nearby in the Washington Channel. Windblown debris can potentially fortify the levee, acting as a further barrier, but it can also help compromise the structure and lead waves over the top. "Breaching is fast," says Resio. "A small breach can quickly become a 40-foot breach, then it's over."

But Gowen's workers would not be to blame. The plan is for the wall, and in a storm the National Park Service's Division of Facility Management crew would surely make their best effort to be at 17th Street to install it. The blame lies with the U.S. Congress and the president of the United States. For example, the Army Corps of Engineers has detailed plans to raise the Potomac Park Levee at a pair of low points, says Ludlam. "But congressional funding to complete the plans and award a contract for construction is not available."

The budget that does exist for levee work would barely be enough to open a string of juice shops, let alone save the nation from disaster. "We receive slightly over $1 million for Dam and Safety," says René Senos, who works with the National Park Service's Dam-Levee Safety Program, "and that million dollars has to stretch from Yosemite to the Washington Mall." Army Corps documents show that, for 2017, the money allocated by Congress for upgrading the Potomac Park Levee System was $0.

The combined destructive force of an overflowing river and a surging tidal system is tough to predict. But Dean Naujoks at the Potomac Riverkeeper has experienced a watered-down version of what might happen. In October 2015, Naujoks was kayaking the Potomac through D.C. as rainfall from a coastal low associated with Hurricane Joaquin sent floodwaters surging downriver. "The water literally started coming in from all sides," says Naujoks, who became trapped on an island in the middle of the Potomac. "The water coming in from the tidal surge basically created a plug. It was like a dam, it just stopped the river, and the water had nowhere to go but up." Naujoks strapped his kayak to a fence and hiked a quarter-mile in water knee-deep and swiftly rising to a higher point, where his wife rescued him.

"If you have to rely on people to put barriers in place," says an Army Corps flood-proofing expert, "there is always the opportunity for something to go wrong." 

If the removable flood wall makes it to 17th Street, is installed correctly, the plastic holds, the trees on the levee don't help pipe water beneath it, waves don't run up and overtop it and debris doesn't smash it open, a 17-foot flood on the Potomac – a height reached by the river in 1936 and 1942 – could still enter the city, because the levee system is peppered with low points. In Constitution Gardens, near a concession stand that sells jumbo pretzels, the berm dips about two feet below its authorized level of protection; just north of the Lincoln Memorial is another low point. In a major flood, these gaps in the levee would need to be closed off with sandbags. (According to Gowen, in the wake of Harvey, the National Park Service realized D.C. did not have enough sandbags for the job, and has since developed a plan to incorporate concrete Jersey barriers and plastic sheeting as well.) There is a third gap in the levee system in southwestern D.C. that would act as a back door. Here water from the Potomac and the Anacostia, a large tributary that enters the main river in D.C., would start creeping north toward the heart of the city.

Any breakdown in D.C.'s ad hoc flood-defense system would unload a sizable portion of the pent-up Potomac on downtown D.C. If the river broke through the levee system at 17th Street, or at the low points near the Lincoln Memorial or Constitution Gardens, a wall of water would spill down Constitution Avenue and rush east into the Federal Triangle. At the National Archives, the water would hit up against a pair of flood walls installed after the 2006 inundation. They've been set to automatically rise when the city's storm drains fill, and may well hold. Other Federal Triangle buildings would not be so lucky. The General Services Administration, which operates a number of agency headquarters, has been working with a private company to design a floodgate to protect a series of moats surrounding the IRS. But the congressional approval required to deploy the gate has not been granted, according to GSA public-affairs officer Renee Kelly. The substantial basement and subbasement flooding that occurred at the IRS in 2006 and shut sections of the building down for six months would likely occur again.

At vulnerable points along the departments of Commerce and Justice, and the Environmental Protection Agency, GSA would have to deploy some 10,000 sandbags. At the National Gallery of Art, workers would have to be quick to install a chain of interlocking barriers to block the flood. But these laborious efforts are not the type that impress flood-risk experts. "If you have to rely on people to put barriers in place," says Randall Behm, the Army Corps lead engineer on non-structural floodproofing, "there is always the opportunity for something to go wrong." Twelve feet of water, the depth of the flow that could potentially be coming down Constitution Avenue, would likely swipe anything not bolted down, smashing windows, pouring down air-intake shafts and seeping in through utility lines.

The deluge would lap against the grounds of the White House and the Trump International Hotel; cross the National Mall; pour onto the lower grounds of the Capitol; and begin rushing down 2nd and 3rd Streets Southwest, near NASA headquarters. Not only would the metro system be grounded, water may well pool across the runways at Ronald Reagan Washington National Airport, and most of D.C.'s major highways would be at least partially underwater. "People would be stranded on little islands," says Resio. When I asked the city's Department of Energy and Environment which backup routes the city would use should the main ones become impassible, the query was passed along to Washington's Homeland Security and Emergency Management Agency. "It's HSEMA's position that this information is sensitive," external-affairs specialist Nicole Peckumn replied via e-mail, "meant to prevent or mitigate potential acts of terrorism."

The U.S. military also has a monumental presence in D.C., with an Army base, an Air Force base, a Coast Guard installation, a Marine barracks, two naval research centers and a major Navy headquarters. Although flood maps show the Pentagon outside the flood zone, "the map," says Galloway, "shows that with the storm surge the Pentagon parking lot will be under-water, along with many of the roads that come into it." For certain employees trying to navigate flooded streets and reach the massive Department of Defense headquarters, he says, "the Pentagon is right across the street from Arlington Cemetery, and that's on a hill, so people could walk through the cemetery."

On the other side of the river, the Washington Navy Yard, the site of the Naval Sea Systems Command – a complex of shipyards and a warfare center – was almost entirely submerged in the 1942 Potomac Flood. Yet Behm, at the Army Corps, tells me the facility has no formal levee system, just "some small individual walls and a little bit of an earthen berm." According to a 2016 report by the Union of Concerned Scientists, the Navy Yard is located in "a hot spot of elevated rates of sea-level rise." Behm has been helping the Navy determine how to floodproof a number of the Navy Yard's 200-plus buildings. "We're looking at benefits and costs," says Behm. "Then results go back to the Department of the Navy, and they determine if they have the funding for implementation. I am guessing it could take several years to go through their budget cycle."

Across the Anacostia River, Joint Base Anacostia-Bolling faces even more serious challenges. Among other important entities, the base houses the Defense Intelligence Agency, the office of military intelligence for the secretary of defense and Joint Chiefs of Staff. The facility is protected by a rutted and crumbling 80-year-old seawall and levee system that has been decertified by the Army Corps of Engineers. During a 2012 inspection, engineers noted "unwanted vegetation" on the levee's embankments, "erosion," "section loss and sliding along landslide slopes," as well as a problem with culverts and discharge pipes. Each of these issues on its own would have caused the levee to fail inspection, which it did. Earlier this year, the Army Corps inspected the levee again, and nothing had changed.

In a major flood, the base's levee system, according to a recent report by the American Society of Civil Engineers, "would most likely be overtopped or incur a floodwall failure." D.C.'s bureaucratic jumble appears to have contributed to the levee's lack of attention. "It is unclear under whose jurisdiction this parcel falls," a 2008 National Capital Planning Commission report stated, referring to a section of the levee that runs under the Frederick Douglass Memorial Bridge, "and which entity ultimately has responsibility for repairs and maintenance."

A variety of physical alternative workspaces intend to keep the federal government running in a natural disaster or national emergency. One is FEMA's Mount Weather Emergency Operations Center, situated, according to a 2015 FEMA fact sheet, "on 564 acres high in the Blue Ridge Mountains, approximately 64 miles west of Washington, D.C." The facility has offices, warehouse space, dormitories, a health unit staffed by medical personnel and a cafe that seats more than 280 personnel, all surrounded by 24-hour security. There is a shuttle and courier service, but there is also the problem of how to get there. "We learned a great deal from Sandy," says Galloway, "and one thing we learned was that the problems weren't just in the buildings – the problem was the employees couldn't get to them to do their jobs."

In Hurricane Sandy, says one national-security expert, "the problems weren't just the buildings - the problem was employees could't get to them to do their jobs." 

Unlike the parade of recent storm tragedies, the fallout in Washington, D.C., would be felt around the globe. It will be hard to play the role of leader of the free world with major federal agencies flooded, defense bases and parts of the intelligence community waylaid, and the president and members of Congress unable to portray any semblance of normalcy. "Anytime you have multiple disasters and threats," says Galloway, "you are creating a potential for confusion and lack of coordination." The disaster will not be the result of a lack of knowledge; rather a tangle of bureaucracy and a culture of neglect will be what dooms America's capital. "The risks we faced 40 and 50 years ago are not the risks we face today," says Resio. "We have not seen anything yet."

In June, at the clubhouse bar of the Capital Yacht Club, a marina located in D.C.'s Washington Channel, I meet Rich McManus, a 64-year-old environmental engineer who lives with his partner, Karen, on a 38-foot sailboat called Free Spirit. Having a boat as a house provides McManus a connection to the sea on a coastline he is convinced is doomed. McManus worked on flood plans for upstate New York right out of college, and as he navigates his evening cocktail he explains to me the problems with our nation's present methods of storm preparedness.

FEMA mandates that levees protect against a hundred-year flood. Coastal communities behind these levees are deemed safe enough by the U.S. government to opt out of paying into the National Flood Insurance Program. Those outside the leveed area are determined to be in a flood-hazard zone. The problem, says McManus, is "100-year-flood maps are compiled from data recorded over roughly the past 100 years." And the weather patterns from the 1920s and the 1950s and the 1970s that created the data points used to calculate America's flood risks have changed. According to a leaked draft of a 673-page National Climate Assessment produced by scientists from 13 federal agencies and presently awaiting President Trump's approval (in late August, President Trump disbanded the assessment's federal advisory panel), the northeast region, which includes D.C., will see not only more rain associated with hurricanes, but heavier episodes of rain in general. Meanwhile, seas could well rise six feet or more by the end of the century. In a world where storms have become stronger, seas higher and rainfall more intense, what used to be a 100-year storm is no longer a 100-year storm. "Ergo, the model is invalid!" McManus shouts over his drink. "Because our baseline assumptions have changed – ergo, we're screwed."

A report compiled in part by scientists at the National Oceanic and Atmospheric Administration, and published in 2013 in the Bulletin of the American Meteorological Society, included a study that found that increases in sea-level rise related to climate change have significantly increased the probability of a Sandy-level flood as compared to 1950. In the future, the researchers continue, rising seas will mean that much weaker storms become "Sandy-level" storms. Another paper, published in 2012 in the journal Nature Climate Change, determined that by the end of the century what is presently considered a 100-year storm-surge flood in New York could actually be occurring as frequently as once every three years. The National Climate Assessment also warns of a potential increase in "the likelihood of compound extremes, in which multiple events occur simultaneously or in rapid sequence," as well as new types of storms. "There is significant potential for our planetary experiment to result in unanticipated surprises," the assessment states, "and a broad consensus that the further and faster the Earth system is pushed towards warming, the greater the risk of such surprises."

Other nations are well aware of this changed risk regime, and are moving forward with upgraded infrastructure. On a hilltop in northwestern D.C. is the Netherlands Embassy, and a very different world. "The term 'once in a hundred years' is relative," Jan Peelen, an attaché for infrastructure and the environment with the Netherlands, tells me inside the embassy's sleek confines, "and it's changing because of climate change." In Britain, the Thames Barrier, completed in 1982, presently protects London against a one-in-1,000-year flood, and the system is being assessed in light of global climate change and rising seas. The Dutch design levees and regulations to protect their cities against a one-in-10,000-year flood, and are considering fixes that would ensure protection against a one-in-100,000-year flood. Over espressos, Peelen runs me through a slide show detailing the elegantly conceived, multibillion-dollar structures that help protect his nation's cities. Building along waterways today is like gambling, he says: "How sustainable is it to keep rebuilding something that keeps getting demolished?"

Meanwhile, most residents of Washington, D.C., and the American public at large, remain frightfully unaware of the risks their capital city faces. Several D.C. agencies have teamed up to pursue a series of assessments, including the formation in 2014 of a multi-agency group called the D.C. Silver Jackets, but without the help of federal money, little work on the ground has actually been done. "It is unfathomable," says Judy Scott Feldman, who chairs the board for the National Mall Coalition, a nonprofit that intends to "provide an organized voice for the public" and "visionary planning" on issues affecting D.C.'s National Mall. In 2013, after working with architects, financiers and scientists, the coalition put forth a plan for an underground parking garage that would sit like a bunker under the National Mall. The facility would help alleviate parking issues, generate revenue and, most important, serve as a vast storage tank for floodwaters in the event of a major storm. Similar systems are already in use in the Netherlands and other European countries. Feldman and her group have met with dozens of members of Congress on the issue. But the effort has yet to gain significant traction. "No government agency has authority on this issue," says Feldman. "The idea is you plan beforehand. You don't wait until it's destroyed."

In August, President Trump issued an executive order that rolled back regulations intended to ensure the federal government factors in climate-change-related flood and sea-level-rise risks when building new infrastructure on the coast and after storms. That same month, Hurricane Harvey made landfall, and the president visited a Houston shelter to pass out prepared meals of hot dogs and potato chips. "He was in an optimistic, nearly exuberant mood," The New York Times reported. "Mr. Trump sympathized with residents, posed for selfies and hoisted one young girl in pony-tails in his arms." A week later, Hurricane Irma skirted past Mar-a-Lago, the president's $175 million estate, located in Palm Beach on a barrier island that sits about seven feet above sea level, before drifting westward instead. "Sometimes it takes your own home being destroyed," Resio says, "before you start caring."