Washed Away

Eroding sand dunes could leave Mauritania’s capital at risk of extensive flooding.
A man looks toward the sea in Nouakchott, Mauritania, on Nov.16. (Photo: Thomas Trutschel/Getty Images)
Dec 15, 2016· 5 MIN READ
Jori Lewis writes about the environment, agriculture and international development for from her perch in Dakar, Senegal. She is currently writing a book about the early history of peanuts in West Africa.

Nouakchott, MAURITANIA—Nouakchott is a coastal city, but most of the time, it pretends not to be. Its orientation is, instead, toward the desert and the savannas, to which most Mauritanians, many of whom were until recently nomads, trace their roots. Just 60 years ago, the capital was little more than a small fort with a small town built around it and a population of 500 people. Over the years, the population grew and grew, and then it exploded.

There are nearly 1 million people living in the Nouakchott area today. As the population swelled during decades of drought, the city extended out in all directions across the low-lying coastal plane, with some areas a bit above sea level and others a bit below. The mayor of Tevragh Zeina, the wealthiest of Nouakchott’s nine municipal districts, said the way that Nouakchott developed has everything to do with its history—or lack of it. “We have very beautiful beaches here, but it’s rare that you would see anyone go swimming. It’s just not our culture,” said Mayor Fatimetou Mint Abdel Malick, who is small in stature—even in high-heeled wedges she can’t stand more than five feet tall—but big in spirit. “We came from other places because of rural flight, so it’s not like we are people who have been here for centuries.” That is why, she thinks, people were slow to see the changes happening on Nouakchott’s coastline, where, over the years, parts of the coastal dune belt that protects the city from the Atlantic Ocean had started to disappear.


There is a path made of compacted sand and sea shells leading to the beach—a path so direct and a surface so hard it had to be made deliberately, although Tevragh Zeina’s deputy mayor, Tijani Ould Boilil, said he does not know who built it or why. The path goes from the coastal road and moves through the brush to the top of the dune, and then it continues almost to the waterline. If you look up and down the coast from there to admire the ocean, you’ll see a sandy ridge with an elevation that rises and falls here and there, but it is, on average, about 20 feet high. “All this succession of dunes that you can follow like a thread—these are the protective coastal dunes,” he said.

It’s the middle of the day, but there is no one here except for a shepherd and a herd of camels munching on the ridge’s sparse grasses. In the areas where the dune ridge dips, it is easy to see why experts are worried. “The danger is that when there is a strong storm with powerful swells,” said Ould Boilil, “there is nothing to stop the ocean.” The ocean might cross the protective dune barrier at a weak point and flow, unimpeded, a mile or two across the mostly empty zones behind the dunes and continue toward the city. This is more than just a hypothesis: The dunes have been overcome by exceptional swells at least five times over the past 30 years, and although the flooding caused only moderate amounts of damage, it sounded the alarm. As global climate change causes the sea levels to rise, the delicate equilibrium between the ocean and the city may become even more uncertain.

Workers build dunes to protect the city of Nouakchott from rising sea levels. (Photo: Thomas Trutschel/Photothek via Getty Images)

The weakest points in the dune chain, where the sand dips down the lowest, were not created by waves and natural erosion—they are mostly human-made, said Sidi Mohamed Ould Lehlou, director of the environment ministry branch in charge of coastal areas. “The sand from these dunes was used in construction for much of the city of Nouakchott in the 1980s and 1990s and even until the early 2000s, and that led the dune belt to deteriorate,” he said. The dunes were also destabilized from overgrazing livestock—yes, those camels—and recreational driving on the dunes with cars or ATVs.

Ahmed Senhoury, the director of the Regional Partnership for the Conservation of the Coastal and Marine Zone of West Africa, based in Dakar, Senegal, said that Nouakchott has other complicating factors. “Much of the city is under sea level, so the water table is high,” he said. That means the city has a tendency to flood when extra water is added to the ground—whether that be water from the ocean, rainwater, or even wastewater, as the sanitation system has not kept pace with the city’s population explosion.

Senhoury first started studying the coastal dune belt and the risk of flooding in the 1990s, when he was a physics student working on his Ph.D. He started looking at the area around Nouakchott’s port, which had opened only about 10 years prior and had been built without any environmental assessments conducted beforehand. The port was causing the largely uninhabited areas just south of the city to erode, and soon after, the coastal dune belt in those areas became a distant memory.

It was that research that led him to write, in 2005, that if nothing was done, by 2025 the damage to the ecosystem south of the port would cause flooding in that area as well as in parts of the city.


The authorities did do a few things. At the port, engineers constructed a dike that slowed and slightly displaced the erosion by slightly altering the direction of the waves and thus the areas where those waves deposit sediment. It is only a temporary solution, however. The government has also been working with a few development partners to start managing the city’s water risks from rain, sewage, and the ocean. The Chinese government is financing an extension of the city’s sanitation system, and the German cooperation agency GIZ has been working on a system to pump water out of some low-lying areas in the case of a driving rain. It also is working with the Mauritanian government to strengthen the fragile coastal dunes.

“We already knew that there had been marine incursions from breaches in the dunes, but we hadn’t yet identified the breaches,” said GIZ project coordinator Omnia Aboukorah-Voigt. Under the auspices of this project, an assessment was done and found 18 breaches, including a couple that stretched over a third of a mile.

Working with the government, the breaches were classified according to severity. Ould Lehlou said the long ones catch people’s attention, but the deep ones are the most dangerous. “As soon as a wave comes, the water can easily enter,” he said.

The project team chose four of the most threatening breaches to fill as a test. They trucked in sand, compacted it to fill in parts of the deteriorated ridge, and planted local trees and shrubs in the sand to help keep it from flying away in the wind.

The filled-in dune does not look that different from the surrounding area, except for the series of long rows of dry vegetation planted along the slope that are too orderly to have been created by nature. But the dip in its elevation is still visible.

“It’s going to take several years before the dune belt is rebuilt. It will need to be protected and managed,” said Aboukorah-Voigt.

The government has planned to keep filling in the other breaches over time. Ould Lehlou said there is also a plan to restructure the fish market, which sits nestled in one of the most problematic coastal dune breaches.

The mayor of Tevragh Zeina remains skeptical about the GIZ project. “I’m not an engineer, but it doesn’t seem conclusive,” said Mint Abdel Malick. She’s done a little research about an alternative method to rebuild the dunes naturally by capturing and trapping sediment and would like to test it out. She noted that often these kinds of projects come from the central government down to the community level. “Sometimes they don’t involve us,” she said.


Aly Hamady Diallo lives in a sparse neighborhood, called Cité Plage, that is still in the process of becoming itself. It’s not that far from one of the breaches the government filled in, and Diallo says he’s not convinced either. “If the ocean comes over, what they did is not going to stop it,” he said.

Diallo owns a small store that sells bread, phone credit, canned goods, and cigarettes to the people in the neighborhood. After heavy rains in 2013 flooded much of Nouakchott, including this area, he noted that some people stopped building here. Other people only paused for a little bit. “As soon as people stopped talking about the danger, they came back,” he said.

Maybe it is human nature to forget what you don’t see.

“Compared to other cities, I think that Nouakchott is really lucky,” Aboukorah-Voigt said, lucky to be a young city. “There’s still time to redirect its development to minimize risk.” Maybe it can be built up in other directions, toward the desert, as people make the choice to give up flood-prone areas and move. Maybe it is already happening.

At 56, Diallo has done a lot of moving because of the weather—because of drought, because of rain. He grew up in the rural Brakna region of southwest Mauritania but moved to Nouakchott a few decades ago to look for new opportunities. When the neighborhood he used to live in started to flood all the time, he gave up his land and moved to Cité Plage. So, for now, he is done moving.

If the ocean should pour over the coastal dunes? “Me, I am not worried,” he said. “I believe in God.”