Vietnam’s Mekong Delta is sinking, but innovations offer hope 

A ribbon of water runs alongside Ho Van Hong’s star-apple and durian trees, just wide enough for the farmer’s blue canoe to glide by. He scoops from the channel to water his orchard in the heart of the Mekong Delta. The grove has been reincarnated from its past life as a rice paddy, one that his family began tilling before the Vietnam War ended in 1975.  

The Mekong Delta is under threat. The land is sinking, eroding away and losing nutrients. So Hong’s family diversified into fruit, ditching the rice monoculture to cope with depleted soil and other environmental incursions on Vietnam, a fertile country whose exports feed people in more than 100 nations.  

Millions across the Mekong are adapting, sometimes with ingenious strategies, in the face of an emerging reality: Their villages are in a slow-motion descent into the sea.

Scientists say half the delta – nearly the area of Sicily – could be submerged before this century is through. Already, homes have begun to collapse into the waters.
    

The Mekong risks becoming a geopolitical tragedy of the commons among countries with clashing interests. It is born of melting glaciers in the Himalayas, the waters collecting into one of the world’s longest and most biodiverse rivers, which slices through China, Myanmar, Laos, Thailand, Cambodia, and Vietnam.

"The delta is sinking at an alarming rate, and the tide is turning against us,” World Bank Country Director Carolyn Turk told Nikkei Asia. At the same time, "we’ve seen successful initiatives have helped farmers adapt, with climate-smart practices and resilient infrastructure. However, a holistic approach is essential.” 

The river is being hemmed in on all sides, from China’s dams in the north choking off natural resources, to rising seas pressing in from the south. Sand mining and groundwater pumping are exacerbating the situation. These cumulative threats mirror those faced by overwhelmed ecosystems globally – and how locals are adapting also could serve up lessons for elsewhere.

The Mekong used to be more ample and steady, so thick with fish they practically jumped into dinghies and rice fields, where Hong would snatch them for dinner. 

“In the old days you could catch such a big fish and just enjoy it,” he said, laughing at the memory as he rowed past bunches of langsat fruit, hanging like a hundred tiny chandeliers. “Now you have to spend money to buy it.”

Now it’s summertime and the living isn’t easy. Fish aren’t jumping and the saltwater is high. Dams upstream aren’t the only cause. But they have held back aquatic life, sediment, and freshwater, which all revitalize the delta and balance the seawater. 

These diminished resources, combined with climate change, overfarming, overfishing, and other human activity, leave the delta a shadow of its former self. 

At the measuring station Tan Chau, water levels peaked at 5 meters in 2000; by 2020 they barely exceeded 2 meters. 

Yet, campaigners say, it’s not too late to act, as they promote ways for livelihoods to evolve with the times. 

From raising shrimp in salty water to cultivating lotus and “floating rice” in floodplains, and from planting mangroves as guardians of the soil to blending fish and duck farming, people of the Mekong are bracing for a changed future. 

“How can you have this melding of local knowledge and research and governance arrangements that enable us to find solutions?” East-West Center fellow Ming Li Yong said. 

Those solutions include cycling through different fruit and vegetables, whose variety can help replenish soils.

Farms like Hong’s are part of the reason the delta doesn’t look like it did a decade ago. Back then, on a drive from Ho Chi Minh City to his town Can Tho, travelers saw barefoot farmers, pants rolled up, trudging through rice paddies. Today there is still rice, but alongside a rainbow of durian, cassava, dragonfruit and catfish ponds.

Yong said it was easy for outsiders, especially city-dwellers, to ignore the remote farmers facing the Mekong’s existential crisis. She noted that those benefiting from hydropower or climate change end up pushing much of the environmental cost onto others.

Locals who grow food reaching kitchens all over the planet, meanwhile, hope that their adaptation measures will preserve as much of their livelihoods as possible, along with the delta.

Human settlement in the Mekong Delta, where the river melts into the sea, stretches back more than a millennium, predating Cambodia's Angkor Wat temples and Genghis Khan's Mongol empire.

Today, more than 70 million people rely on the river for their livelihoods. But the once-expanding delta, shaped by deposits of silt brought downstream for thousands of years, has been slowly receding in the past four decades.  

One change has been the damming of the Mekong.

“Rivers, and so the Mekong, are organic entities – what is done in one part of the river affects the river in its entirety,” Milton Osborne, author of “The Mekong: Turbulent Past, Uncertain Future,” told Nikkei. “Hence once the Chinese and then the Lao started building their dams, there was never going to be a return to the Mekong’s wild river character.” 

He laments the devastation of farms and fish stocks since construction of the “cascade of dams” on the “cruelly tamed” Mekong began in 1984, and the MRC’s inability to block dam building. 

Laos, Thailand, Cambodia and Vietnam in 1995 formed the MRC to manage the shared waters. Conspicuously absent from the coalition is the most powerful riparian country: China.

China’s water-based tensions with Vietnam are always on a simmer because of their clashing claims in the South China Sea. But the world’s two biggest communist countries attempt to project friendly ties, each seeing the other’s ruling party as crucial to its own. Still, Hanoi has become more assertive, criticizing “unsustainable development projects upstream” at the MRC Summit in April.

“No rivers can return to the past,” MRC Secretariat CEO Anoulak Kittikhoun told Nikkei. He said countries must prioritize goals, like saving wetlands, and “balance between development and environmental protection. And I think it’s not too late.”

Meanwhile, Vietnam's renewable freshwater resources have declined significantly over the last few decades.

While the commission can’t force change on China, dubbed the "upstream superpower," Beijing did agree in 2020 to share water-flow data with the commission.

Smaller neighbors can use the deal, along with “behind-the-scenes” negotiations, to press Beijing for transparency and compare its data to their own, said Yong, who focuses on transboundary governance of the Mekong River Basin.

“This might incentivize China to be more cooperative because it’s less able to hide data about its dam operations," Yong said. The MRC hopes China will eventually share sediment data.

In the course of three decades, dams may decimate nearly all the soils that swirl down to the delta – by 2040 it could be left with just 3% of its 2007 sediment levels, the commission has projected. In such a situation, MRC's Anoulak said, “it will cease to be the Mekong.”

Still, there is an increase in downstream countries’ joint planning for how they exploit the river, and in joint studies with China that “build trust,” he said. “We would have liked it to move much faster. But we have reality to wrestle with.”

The attenuated river flow creates and compounds other stresses on the delta, such as extraction-induced subsidence. With less water arriving, farmers pump it from the ground, which is sinking as a result.

As less sediment reinvigorates the soil, farmers turn to fertilizer. Some have increased fertilizer use as much as 40% in the past five years, says Nguyen Van Phong, whose Can Tho Farms pushes growers to try natural substitutes for chemicals.

At his farm, fish swim underneath rows of chard and romaine, their discharge fertilizing the leafy greens. He hopes nature-based adaptation will mean fewer toxins pouring into the Mekong. 

“I used to bathe in the river, I’d dive right in, then I’d carry water back for cooking, it was normal,” Phong said, kicking off his slippers to sit down at the farm, where rabbits nibble stalks, vermillion peppers dangle and barbary doves cackle.  

Phong's approach resembles some of the World Bank’s “living with nature” projects for a million Mekong residents. In the crop-fish-duck project, the birds paddle in the rice paddies, eat insects and weeds, and kick up water, circulating nutrients. Duck and fish waste also fertilizes the earth.

Many growers who have long harvested three rice crops a year are replacing one cycle with fish. Besides easing the monoculture, which exhausts the soil and is threatened by pests, the switch means they can farm in cycle with floods. Instead of diverting water with dikes in monsoon season, they let it wash over the fields and raise fish in the marshes. 

Lotus farming is another way Vietnam is leaning into flood-based agriculture. The delta has introduced dozens of lotus products in the past five years, weaving lotus fiber into expensive scarves and drying the seeds for a health snack. The roots get folded into salads, other parts make their way into wine and cosmetics.

The “floating rice” strain, meanwhile, grows tall without insecticide or herbicide, come pest or high water, making it flood-resilient. But it doesn’t taste as good as other rice grains, something that An Giang University’s Climate Change Institute scientists are trying to change.

“Floating rice is well adapted to flooding,” the institute’s Vice Director Le Thanh Phong told Nikkei. “The stored water can also slow down the outflow to the river or sea.”

Farmers retain more of the floodwater in the rainy season, so when it washes out in the dry season, the freshwater serves as a counterweight to the encroaching South China Sea. But with upriver dams, and droughts induced by climate change, freshwater has declined. 

So living with saltwater is another impetus for locals to convert rice paddies to aquaculture ponds in the wet season, often for shrimp.

The governmental Australian Center for International Agricultural Research (ACIAR)  assessed shrimp-rice aid programs in the Mekong over the course of two decades, and concluded that each dollar spent on aid had generated $72 in returns. This was calculated based on the number of farms that moved to shrimp-rice farming, and the profit that was generated as a result.

The World Bank estimates that these and other changes have benefited 788,000 of the eventual goal of 1.2 million residents. 

Dong Thap, one of 12 delta provinces, worked with the bank to help 62,000 locals add ducks, perch, tilapia or shrimp to their rice paddies. The province reported a rise in profits of at least 20%. Higher productivity stemmed from removing one of the three rice crops, which cut pest cycles, combined with fish that can clean the water and enrich the soil. 

“These things are all interconnected,” Andrew Wyatt, Mekong deputy head at environmental group IUCN, said in an interview. “There’s a lot more diversification going on now. That’s a positive we’ve seen.” 

But some shrimp farmers also razed mangroves and pumped groundwater, which intensified erosion and sinking. In response, residents are installing embankments, replanting mangroves, and raising clams, snails and shrimp that coexist with the swamp trees. 

The mangroves guard the coast as oceans swell. If greenhouse gas emissions go unchecked, the sea around Vietnam may rise as much as a meter by 2100, according to the Ministry of Natural Resources and Environment.

In that scenario, the World Bank said, nearly 50% of the delta would be under water. Infrastructure remains vastly outmoded in the delta, which the World Bank says needs connectivity and flexibility, such as sluice gates to manage salt or water levels. 

Deeper inland, Hong and his family are glad they embraced fruit after it became harder to eke out a living on rice. Four generations still live on the same plot, including his brother Ho Thanh Tung. 

They see some neighbors still tending rice, their yields at times falling along with water and sediment levels, Tung says. On hydropower and dams, he says there are some advantages but “the disadvantages are many.” He steps out for a minute to help his grandfather, who lost both legs in the war, to get to the bath. 

All over the delta, generations of farmers are born in these fields and spend entire lives never leaving. Cyan and ruby tombs remain embedded among the rice stalks for decades, a daily ancestral reminder. 

When asked about the future, Tung said he is interested not in buying cars or vacations but in continuing a quiet existence with farm and family. He acknowledges, though, that the changing world around him means he might have to reinvent his life again.    

“We plant star apples and durians, that is what brings us income. But in five, 10 years, we can't be sure of what trees will be best,” he said. “When we get to that point, then we will figure it out.”

(This article is the third and final in a three-part series in which Nikkei Asia explores the effects that the actions of upstream nations – exacerbated by climate change – have on countries downstream.)