On a late fall afternoon on the western edge of the Netherlands, coastal engineer Marcel Stive stands atop a 40-foot dune. He stares out beyond the posse of wet-suit-clad surfers wading into the breakers of the North Sea. Where the surfers see inviting waves, Stive sees dry land—and a distant storm. He points south toward Rotterdam, Europe's busiest port. Arm outstretched, Stive rotates 180 degrees to face the shoreline running north. "As far as you can see, in both directions, we're going to push the coast out 3, maybe 4, kilometers," he says. "We have to—to keep the water out."
The
dunes here alongside the village of Ter Heijde are among the weakest links in
the complex network of natural barriers, dams, levees, canals, pumps, and
storm-surge barricades that keep this lowest of low countries dry. More than
half of the Netherlands sits below sea level, and if a megastorm were to break
through these not-so-formidable dunes, the water could inundate Rotterdam and
surrounding cities within 24 hours, flooding thousands of square miles,
paralyzing the nation's economy, and devastating an area inhabited by more than
2 million people.
Global
warming is a cause for serious concern in low-lying countries. The Dutch aren't
waiting for a catastrophe; they're taking measures to solve the problem now.
For
more, visit wired.com/video.
Stive
is part of a Dutch team charged with reducing that risk. Narrowing the gap
between the Netherlands and North America by a couple of miles would be a
start, and as a bonus it would create valuable new real estate for recreation
and development. Also on the drawing board are massive new storm-surge barriers
and reinforcements around cities like Rotterdam and Dordrecht, built on the
marshy delta where the Rhine and Meuse rivers meet the sea. "If you see a
certain future, you must react," Stive says. And as he sees it, that
future looks wet.
 |
| More than half of the Netherlands sits below sea level, and if a massive storm were to break through the dunes, Rotterdam would be inundated in 24 hours. Photo: Ralph Hargarten |
Yet
the chance of a breach at Ter Heijde is actually quite low, about 1 in 10,000
in any given year. (In the lingo of storm protection, that's known as a
10,000-year flood.) The coastline and river deltas of the Netherlands are
arguably the best-protected lowlands in the world, and the Dutch are a little
miffed at Al Gore for suggesting in An Inconvenient Truth that their homeland
is as vulnerable to rising seas as far less protected places like Bangladesh
and Florida.
To
Stive and other sea-rise hawks, however, 1 in 10,000 has become too risky. They
want to crank up defenses in some critical areas to the level of 1 in 100,000.
"To understand risk, you must consider the value of what would be
lost," says Stive, a pink-faced man of 57 years who heads the coastal
engineering and water research centers at Delft University of Technology, just
north of Rotterdam. The half of the country that is below sea level—including
the area behind these dunes—generates about 65 percent of its GDP. That's
nearly $450 billion a year.
 |
| A deadly flood hit the Netherlands in 1953, covering more than 600 square miles and killing more than 1,800 people.Photos: Getty Images |
There
is, of course, another factor to take into account: Global warming is
increasing the odds of a catastrophic breach. That means the risk calculations
need revamping. New projections of sea-level rise and other potential consequences
of climate change, coupled with the aftershock from Hurricane Katrina, have
prompted Dutch officials to ask a very big question: What would it take to
climate-proof our country for the next 200 years?
In
2007, the parliament assigned a team of experts, dubbed the Delta Committee, to
come up with an answer. The group's final report, published in September,
proposes a combination of aggressive new steps—extending the coastline and
building surge barriers—and time-tested strategies like fortifying levees. The
cost: about $1.5 billion a year for the next 100 years.
Of
course, a 200-year plan seems absurd. Two centuries ago, it would have been
impossible to predict how civilization and the planet would look today. But the
Dutch insist that the project is prudent and rational. If they start now, the
costs will be minimized and disaster, perhaps, averted. After centuries of
damming, pumping, barricading, and redirecting water, the Dutch water masters
are laying the foundations for what may be the most ambitious act of
territorial defense in history. In so doing, they are giving engineers and
urban planners from New Orleans to Singapore a preview of what it will take to
keep rising waters at bay. "We have the safest river delta in the
world," Stive says. And, he adds, they want to keep it that way: "We
will completely control the water."
Floods
may be among today's more ominous climate-driven hazards, but the Dutch know
better than anyone that they're nothing new. Below a bridge crowded with
bicycles in the groovy Amsterdam neighborhood of Jordan, canal boats full of
beer-soaked vacationers glide past a heavy black gate. On the side of the
bridge is a small block of white marble, high above the waterline, with a
horizontal cut across the middle. It shows the high-water mark of 1682 and is
accompanied by an inscription reading, Zee dyks hooghte zynde negen voet vyf
duym voven stadtspeyl.Translation: The sea dike level is 9 feet 5 thumbs above
city level.
The
327-year-old gauge is high and dry today because in 1932 Amsterdam's labyrinth
of canals was sealed off from the ocean by the 19-mile-long Afsluitdijk
(Enclosure Dam). That feat of engineering created Lake Ijssel, one of the
largest freshwater lakes in Europe. It also cut Amsterdam off from tidal
changes and storm surges, permanently lowering the city's waterline.
How
to Climate-Proof
a Country
The
Dutch have laid out a 200-year plan to defend against rising sea levels. Here's
a look at the major upgrades. — David Wolman
1
// Raise the Lake At
low tide, the North Sea now drops far enough that gravity can drain excess
water from Lake Ijssel. But that won't work if the oceans rise. The plan: build
up the height of the lake's enclosure and raise the water surface by up to 5
feet.
2
// Extend the Coast To
fend off swelling seas and raging storms, engineers want to push the coastline
out by as much as 2.5 miles. Dredging ships would suck up ocean sand and dump
it on the edge of the beach, adding 400 square miles to the country.
3
// Dam the Waters Rotterdam,
Europe's busiest port, is already protected by an extensive network of dams,
dikes, and dunes. The new plan would augment that system, raising the height of
existing structures and adding four giant flood barriers.
Infographic:
The Department for Information Design at Copenhagen
Some
3 billion people—at least half the world's population—live in coastal areas
vulnerable to the worst effects of global warming: harsher storms, rising sea
levels, flooded deltas in winter, parched deltas in summer, and less sensational
but equally serious problems like salt water infiltration of underground
aquifers. By 2025, when the human population reaches 8.5 billion, the number of
coastal dwellers is expected to be closer to 6 billion.
 |
Marcel Stive, coastal engineer for the
Delta Committee Photo: Ralph Hargarten
|
Success
in holding back the sea has earned the Dutch an international reputation as
experts in reclamation and flood protection. But that knowledge has been
acquired through painful experience. In February 1953, a massive storm surge
inundated 600 to 800 square miles of the country, killing 1,835 people. After
the disaster, the government devised a plan so that the people of the
Netherlands could confidently say: never again.
The
initiative triggered a 30-year campaign of bulwark construction, known as the
Delta Works, to reduce the country's flood vulnerabilities. Dams and levees
were built to cut tidal areas off from the open ocean, shortening the exposed
coastline by nearly 450 miles. The flagship projects are the 22-year-old
Oosterschelde storm-surge barrier and the 11-year-old Maeslant barrier, a gate
made up of two giant arms, each nearly the size of the Eiffel Tower. In the
event of calamity-level storm waters, the barrier will close off the mouth of
the New Waterway leading into Rotterdam.
The
megastructures are impressive, but what may prove to be the most visionary
aspect of the Delta Works is the statistical approach that guided the designs.
How high should we build the levees? How strong should a surge barrier be? The
Dutch decided to base their answers to these questions not merely on the fact
that storms are destructive and the Netherlands low, but also on economics.
With the help of renowned Dutch mathematician David van Dantzig, the 1953 task
force calculated safety levels using an equation that is now seared into the
minds of Dutch engineers:
risk
= (probability of failure) x (projected cost of damage)
This
kind of risk analysis is common today in fields like nuclear power, aerospace,
and chemical manufacturing. But back in the 1950s, accounting for the projected
cost of damage when developing flood protection was novel. The power of this
simple formula is that it produces economically rational public-safety
decisions: Less value, less protection. Dutch law now requires this principle to
be used to determine the strength of flood defenses throughout the country.
Since the dunes at Ter Heijde sit between the sea and a vulnerable but
economically vibrant area, a safety level of 1:100,000 is called for. More
rural parts of the country require safety levels of just 1:1,250 or lower.
In
a Rotterdam office built atop a levee on the New Meuse river, Cees Veerman is
sketching lines on a map of the Netherlands. A farmer-economist-politician,
Veerman is the head of the new Delta Committee. He was only 4 years old the
night of the 1953 flood, but he remembers his grandfather racing into the
kitchen to grab a knife. "He was about to run out and cut the cattle loose
and move them to higher ground," Veerman recalls. The townspeople in his South
Holland village of Nieuw-Beijerland assumed the storm waters would rise
gradually. Instead, a wall of water bulldozed through the dikes. Their lives
were in danger, but there was little to do except pray. Suddenly, the water
level began to drop—their prayers had been answered. "Everyone was
shouting, 'The water is falling!'" It wasn't a miracle, though; the water
had merely barreled through the far-side levees, relieving the buildup at the
Veerman family farm while inundating areas farther inland.
To
climate-proof the Netherlands for the next two centuries, Veerman and his team
first needed to gather the best possible data. Most existing projections of
sea-level rise look at the oceans as a whole, not at specific regions. So the
Dutch commissioned their own forecasts. Developed by some of the engineers and
ocean experts on the Intergovernmental Panel on Climate Change (the group that
shared the 2007 Nobel Peace Prize with Al Gore), the models predict that the
North Sea will rise 40 centimeters by 2050, between 65 centimeters and 1.3
meters by 2100, and up to 4 meters by 2200.
 |
| On the drawing board for reducing the risk of flooding are massive new storm-surge barriers and reinforcements around cities like Rotterdam and Dordrecht, built on the marshy delta where the Rhine and Meuse rivers meet the sea. Photo: Ralph Hargarten |
Veerman
talks about Dutch can-do the way generals talk about staying the course in a
prolonged military battle. "People say sea-level rise will push us back
into the hinterlands," he says. "We say no, we can manage with 1, 2,
even 3 meters. But we have to act." With a black pen, he inks in an
expanded coastline on the map laid out before him. Extending the country
westward will be a colossal reclamation effort: Dredging ships, working just offshore,
would spend the next century vacuuming up roughly 121 million cubic meters of
seafloor sand every year and spraying it toward the shoreline, where wave
action would then deposit it at the water's edge and "naturally"
build the beach outward. Over the course of 100 years, the project would add
about 400 square miles to the Netherlands—roughly equivalent to 17 Manhattans.
Next,
Veerman sketches in future storm-surge barriers, adds a new channel for
diverting the flow of the Lek River, and draws a line connecting a small chain
of islands off the northern coast that may someday be linked up to form a giant
buffer against the North Sea. He also circles a swatch of farmland near the
confluence of the Rhine and Meuse rivers. Global warming doesn't just bring a threat
from the ocean; greater precipitation in the Alps is expected to increase the
amount of water flowing through Europe's major rivers, raising the flood hazard
from within. Veerman explains how this circled area will be converted back into
wetlands, giving the rivers room to flood in a place that makes sense—not
downtown Rotterdam.
Then
he brings his pen north to Amsterdam. At present, when water levels in nearby
Lake Ijssel get too high, water managers release the excess through the
Enclosure Dam and into the sea. Gravity is currently able to move the water
during periods of low tide, when sea level falls below that of the lake. But
that will stop working as the ocean rises. One option is to pump the water out,
but the expense would be prohibitive. Instead, Veerman wants to raise the level
of the lake on pace with the sea, as much as 5 feet by 2100.
From
the air, you can see why this would be a bitter pill for Amsterdam's booming
satellite towns—especially the posh developments along the lakeshore, which would
have to be fortified by higher dikes. But the price tag on the proposed lake
project, as much as $8.2 billion over the next 100 years, is only a fraction of
what it would cost to build and run a pump system or to repair damages if the
lake overflowed into 10,000 living rooms.
Today,
life around the periphery of Lake Ijssel—and throughout the Netherlands—looks
so peaceful, it's hard to envision disaster. Because of that, protests seem
inevitable. Environmentalists will no doubt be hostile to the idea of a
century-long dredging project, relocated farmers will put up a fight, and
condominium owners around the lake may resist anything that interferes with
their views. But Veerman and his colleagues are convinced that bold measures
now are necessary to prevent calamity tomorrow.
The
wind rips through the dark skies above New Orleans. Hurricane Ike is hours from
making landfall at Galveston, Texas. New Orleans should receive only a glancing
blow, but residents are hardly at ease: Tropical storm and tornado warnings are
expected to last through much of this September afternoon and evening. Just two
weeks ago, Hurricane Gustav forced an evacuation of 2 million people and pushed
the city's unfinished levee system to the brink.
 |
| The Maeslant barrier and the Oosterschelde storm surge barrier are the crowning jewels of the Delta Works. Because of the accelerating rise in sea level, the Dutch will have to build additional mega-structures to guard against flooding. Photo: Ralph Hargarten |
On
the east side of the Inner Harbor Navigation Canal, Mathijs van Ledden climbs a
muddied slope toward a recently constructed flood wall. Behind him are the
devastated blocks of the Lower Ninth Ward, an eerie mixture of abandoned lots,
weed-covered foundations, and a few refurbished or newly built houses.
The
canal connects the Mississippi River to the Gulf Intracoastal Waterway and Lake
Pontchartrain. The flood wall was built soon after Katrina, to plug what was
one of the most catastrophic failure points along the city's roughly 350-mile
network of levees and floodwalls. Van Ledden, an engineer with the Dutch
consulting firm Haskoning, has been in New Orleans since 2006. His job: Run
wave and water models for the US Army Corps of Engineers to help determine the
necessary height of new defenses.
Shouting
over the wind, Van Ledden, 33, says a stormy day is ideal for touring the
city's flood-protection maze. He leans over an older flood wall that runs
perpendicular to the new, higher one. Ike has raised the water level in this
canal 5 or 6 feet above normal. "During Gustav, the level was all the way
up to here," Van Ledden says, placing his hand just below the top of the
wall. "And Gustav was just a friendly wake-up call. In 50 years, if the
sea level goes up 1 or 1½ feet, the level for that storm would be here,"
he says, holding his hand well above the top of the flood wall. To make sure
that doesn't happen, the Corps is planning to build a giant storm-surge barrier
between Lake Borgne and the Gulf Intracoastal Waterway. The barrier's gates
would close during extreme storms, blocking lake water from funneling up into
this narrow canal.
After
Katrina, Congress ordered the Corps to bring the city's hurricane protection
system up to 1:100 levels by 2011. If a 1 percent per year chance of system
failure sounds high—compared with existing 1:10,000 defenses in the
Netherlands—that's because it is. "One-hundred-year protection is quite a
risk," Van Ledden says. Statisticians will tell you that over the course
of a 30-year mortgage, the chance of a 100-year flood hitting the city is more
than 25 percent. The 1:100 standard takes projected sea-level rise into
account, but not economic impacts and repair costs. (Hurricane Katrina caused
upwards of $150 billion in damage.)
 |
Cees Veerman, head of the Delta Committee
Photo: Ralph Hargarten
|
So
why don't we do it like the Dutch? The glib answer is that we should. Van
Ledden and colleagues have run the numbers for New Orleans, and he says
investment in a protection level of at least 1:1,000 is economically justifiable
in some areas. That is, the cost of boosting protections to that degree is
modest in relation to the huge reduction in risk. And if you settle for
mediocre defenses and they get wiped out, you also lose your initial
expenditure.
But
the Dutch model may not work in the US. That's partly because our hurricanes
are so severe. Consider this: The levee height required for 1:100 protection in
some areas of New Orleans is roughly 30 feet—the same height as fortifications
in the Netherlands that provide 1:10,000 protection.
In
any case, American politicians could never get away with basing flood barrier
specs on the value of what sits behind them. Ratcheting up defense levels in
New Orleans to match those in the Netherlands would lead other areas of the Gulf
Coast to demand equal treatment. And what about earthquake zones in California,
floodplains in Iowa and Missouri, or blizzard territory in New England? Should
similar standards be applied there?
Van
Ledden says many Dutch citizens may not know it, but their government has
accepted—even legislated—unequal protection, or what engineers euphemistically
call "differentiation." Everyone knows that all places can't be
protected up to the same standard; individual cost must be balanced against
collective cost, he says.
The
US certainly has variable protection levels throughout the country, but there's
a difference between de facto disparity and an explicit government policy of
inequality. Imagine if Congress or the Army Corps were to recommend protecting
the French Quarter and downtown New Orleans at the 10,000-year level while
giving less economically productive areas such as St. Bernard Parish only a
100-year level of protection. Applying the Dutch model of risk-based design
would be a political nonstarter, if not unconstitutional, and the efforts of
the Army Corps of Engineers would in no time be halted by an army of lawyers.
Meanwhile,
the water keeps coming. The Dutch are taking on the threat of global warming
before anyone's feet are wet. They're showing the world that to prepare for
sea-level rise and other impacts of climate change, you need, paradoxically,
not dominion-over-nature bravado but patience, good data, and—above all—the
long view.
Contributing
editor David Wolman (david@david-wolman.com) wrote about Egyptian activists
using Facebook in issue 16.11.
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