Some 60 million people rely on Southeast Asia's Mekong River for their sustenance. But the Mekong is under threat.
While China is building dams that sharply reduce the water flow and sediment downstream, other countries along the river share some of the blame.
Cambodia, for instance, is experiencing a building boom that is transforming its capital, Phnom Penh. Sitting at the confluence of the Mekong and the Tonle Sap rivers, the city's low-slung French colonial architecture is being replaced with high-rise apartment buildings, malls and luxury car dealerships. Sand from the Mekong's sediment is key to that construction growth.
"The benefit from sand dredging is both direct and indirect," says Yos Mony Rath, head of the Cambodian government's Mineral Resources Department. "The sand used in the construction industry helps create jobs and grows the economy. And dredging the river helps make it wider and deeper for boat traffic."
Not only that, he says, but "Phnom Penh is lowland and we need to fill it in before we can begin construction and grow the national economy."
Environmentalists point out that the capital has filled in many of its lakes, including the Boeung Kak, to make way for condos and coffee shops, hampering Phnom Penh's handling of runoff from the annual monsoons and exacerbating flooding.
What's more, taking too much sand from the Mekong is also causing problems for the people who live alongside it.
"When you extract all the sediment from the beds of a river, the river looks for new sediment," says Brian Eyler, a Southeast Asia expert at the Stimson Center think tank and author of Last Days of the Mighty Mekong. "So it pulls the banks of the river into the river, and this has resulted in roads collapsing into the river and lines of homes and towns falling into the river."
In the sand miners' eagerness to extract the sand, not even the dead are safe. Just ask Bean Boren, a monk at the Kdey Takoy temple complex on the Mekong, just outside Phnom Penh.
"One morning, the riverbank started sliding into the river while the boat was pumping sand just offshore, taking two of the temple's stupas [crypts] and the coffins inside with it," he says.
"We managed to pry them open and drag the coffins out before they floated away," he continues. "But the abbot was very angry at the dredging company."
The abbot raised the matter with local authorities, but nothing happened, the monk says. That was over a year ago. When NPR recently visited the temple, another dredger was pumping sand into a barge not 10 yards offshore. Standing on the riverbank in front of the temple, the monk pointed to a foot-wide crack in the ground that he blames on the dredging.
"We're trying to shore up the riverbank to try to protect the [remaining] stupas," he says. "Otherwise you'll see another report on TV about stupas falling into the river and us trying to save the coffins again."
An attempt to interview workers on the dredger prompted them to raise anchor and motor away.
"It's all about the money. The business, the benefit, not about the environment or the people," says Hun Vannak, an activist with Mother Nature Cambodia, an environmental advocacy group. He spent five months in prison beginning in 2017 for protesting illegal sand mining when Cambodia was selling huge amounts of sand to Singapore, the tiny city-state that has been buying sand from Southeast Asian countries for years in an effort to increase its landmass. The uproar and bad press over Cambodia's dredging of its coastal wetlands led Cambodia to officially ban sand exports in 2017.
But there's plenty more for the miners to find and sell domestically. And that worries environmentalists like Vannak.
"We are doing too much sand mining right now, and we do not control it," he says.
He complains there's no government transparency when it comes to sand mining in Cambodia. So no one really knows what's legal and what's not. The sand miners, he and other environmentalists say, work for companies linked to powerful tycoons with government connections. In theory, the mining companies are required to file environmental impact statements and abide by the rules. In reality, critics say, the only rule is making money.
"I don't think those allegations are true," says Mony Rath, the mineral resources director-general. "We have our hotline for people to inform us of illegal sand dredging, and we would take immediate action," he says. "We have never received a complaint."
A little way out of the city, on the Bassac River, a tributary of the Mekong, farmer Mon Mut slaps her leg and laughs when she hears that explanation. When the back of her house started falling into the river, she says, "I tried to call on that number, but they never answered the phone or it was busy." So she gave up.
She holds a document from the company that dredged in front of her house and that accepted responsibility if anything went wrong. But in late 2017, when her house started collapsing and she asked the authorities to intervene, they told her to "stop complaining" and blamed the incident on a "natural disaster." She says she never saw this kind of natural disaster until the dredgers arrived.
Nine of her neighbors, she says, had it far worse than she did — they lost their entire houses.
"We have no power against them because they have the law," she says, alluding to the dredging companies' alleged connections with the government and the courts. "If they come back and dredge like last time, I think all the houses on the river will fall down."
Marc Goichot, the World Wildlife Fund's Mekong program director, says the majority of the Mekong's sediment loss has come from upstream damming by China. But the indiscriminate sand dredging in downstream countries such as Cambodia, Thailand, Laos and Vietnam has made things even worse.
"We have lost, since 1994, 77% of the total sediment transported by the river [the Mekong], which is huge," Goichot says.
"The demand is great, and the extraction is already absolutely not sustainable," he says, "because we are probably extracting somewhere between 60 and 80 million tons a year when the river today probably barely produces 5 [million tons]."
That's bad news for the 20 million people who live in the Mekong Delta and depend on river sediment from seasonal flooding for growing crops. And the fish in the world's largest freshwater fishery depend on that sediment too.
While Cambodia's mineral resources director says he is worried about upstream damming by China, he is optimistic.
"I believe that we have to protect what we have," Mony Rath says. "The Mekong and the Tonle Sap Lake can supply the food as fish and provide for our local people and tourism," he says. "If we think about the fast-growing economy of Cambodia, I believe that Cambodia has enough sand resources to develop ourselves."
Vannak has a different take.
"They are killing the river," he says.
Farther downstream, Vietnam is also contributing to the problem, he says. "They're killing their own river too," he says. "Because the government [there] doesn't really care either."
Michael Sullivan reported in Phnom Penh, Cambodia.