Two leading experts on water issues in Asia warn that parts of Vietnam's fertile southernmost areas bordering Southeast Asia's longest river, the Mekong, are in danger of drying up.

At the same time, they say, much of the Mekong is still flooded from seasonal monsoon rains. And citizens in places such as Pakse, the second most populous city in Laos, confront dangerous floods.

Brian Eyler at the Washington D.C.-based Stimson Center and Aaron Salzburg at the University of North Carolina also warn that a severe drought could threaten farms and fisheries in key parts of the river basin.

More than 60 million people depend on the Mekong for food and transportation. For many, fish from the river provide their main source of protein. Many children's health depends on that protein.

The Mekong River originates in Tibet and flows for more than 2,700 miles through China, Myanmar, Laos, Cambodia, Thailand, and Vietnam, where it enters the South China Sea.

For more than two months, most parts of the Mekong basin have recorded record low water levels, Eyler and Salzburg say.

In recent years, China, Laos, and Cambodia have all built dams that obstruct natural water flows. And the three nations have continued to construct dams regardless of the impact this has on other countries' farms and fisheries.

The intergovernmental Mekong River Commission (MRC) based in the Laotian capital of Vientiane warned recently of increased rainfall brought in by a cyclone from the middle part of the lower Mekong basin down to Pakse in Laos.

But the MRC has no power to implement best practices to mitigate the impact of either flooding or drought. Its studies, however, can prove useful to regional nations.

One study cited by Eyler and Salzburg serves as an example: Conducted by the MRC in 2017, the study estimated that monsoon flooding in the region provided $8 billion to $10 billion U.S. dollars in annual economic benefits while costing less than $70 million in damages.

"In other words, the seasonal flows of the Mekong are critical to ensuring the river's survival in its current form," the two experts said.

When it comes to dams, Laos, the poorest of these countries, has been building dams both on the Mekong and on tributary rivers with the aim of becoming the "battery of Southeast Asia." But Eyler has long argued that hydropower in Laos has mostly benefited Thai banks and Chinese construction firms, with Laos receiving little of the revenue from the dams.

Eyler is the author of a book titled Last Days of the Mighty Mekong, which was published in February.

To the south of Laos, Cambodian fishermen have long complained that upstream dams in China and Laos have disrupted fish migrations, causing a drop in the fish population in Cambodia's Tonle Sap Lake.

The Tonle Sap, the largest freshwater lake in Southeast Asia, is often described as "the heart of the Mekong."

But seasonal floods have not yet raised the level of the lake to its normal monsoon-season size, Brian Eyler said in response to an email query.

The Tonle Sap would normally increase its level by four times during the monsoon season.

Three Mekong River countries move apart

Cambodia is reviewing plans to build two huge dams on the Mekong mainstream, but Eyler and Salzburg question whether such dams would make economic sense given the dramatic decline in the cost of solar and wind power.

Cambodia has the land needed to accommodate solar and wind power, which have the advantage of being both relatively low cost and environmentally friendly.

Vietnam, meanwhile, has protested against the dams being built in Laos and Cambodia but without presenting any alternatives.

The result: "Instead of bringing these countries together, the discordant development of the Mekong is pushing them apart," Eyler and Salzburg say.

The nonprofit organization International Rivers, based in Oakland, California, noted in April this year that a 2018 MRC Leaders' Summit Declaration stated as a priority that a Mekong River Council Study should be used in planning river projects.

"Yet Mekong governments have yet to explain how the study will inform their decision making," the organization said.

Bertil Lintner, a writer and Southeast Asia expert, said in a recent article written for the Hong Kong-based Asia Times that in recent years China "has managed to outmaneuver the MRC."

It has done so, Lintner says, by creating its own Lancang-Mekong Cooperation organization. Lancang is the Chinese name for the Mekong.

And according to International Rivers, China has rejected offers from the International Finance Corporation (IFC) and the MRC to participate in watershed management planning.

The IFC is a branch of the World Bank which is headquartered in Washington, D.C.

China's presence and infrastructure projects have grown throughout the region to the point where some experts say that China now dominates the Mekong and has turned it into a transportation route for its ships regardless of environmental concerns.

U.S. Secretary of State Mike Pompeo joins Southeast Asian counterparts at a gathering of the Lower Mekong Initiative, in Bangkok, Aug. 1, 2019. AFP Mekong Delta shows what can go wrong

Meanwhile, everything that could possibly go wrong comes together in Vietnam's fertile Mekong Delta. And the stakes are high.

As Delta ecologist Nguyen Huu Thien explains, the Delta is the main food basket of Vietnam and home to 18 million people. It produces more than 50 percent of the country's food, 90 percent of its rice exports, and 65 percent of its fruit while providing 75 percent of its fish.

The Delta still suffers from the impact of attempts by the Communist government after it took power in South Vietnam in 1975 to increase rice production. In order to expand the space for rice production, the government encouraged the destruction of mangrove swamps. But the mangroves that were destroyed performed the vital function of protecting the Delta from salt intrusions.

Add to all of this the impacts of climate change and the upstream hydropower dams which have blocked much of the sediment that once reached the Delta and replenished it with nutrients, and you have a disaster in the making.

On June 19, Eyler explained in a paper co-authored with Jake Brunner of the International Union for Conservation of Nature (IUCN) in Hanoi how this could come about.

"Without sufficient sediment to replenish the land," they said, "the delta will sink beneath the East Sea-a problem compounded by unsustainable groundwater pumping and a rising sea level."

A look at one district in Camau, the southwesternmost province of Vietnam, shows how high tides from the South China Sea, also called the East Sea, can cause heavy damage to villagers living near embankments meant to hold back the sea.

Eyler and Brunner suggest that Laos and Cambodia can address Vietnam's concerns by prioritizing dams that minimize the downstream impact on Vietnam while expanding the use of non-hydro renewable energy sources.

Vietnam, for its part, can invest in a national electricity grid in Laos that allows Laos to charge transmission fees. Working together, Vietnam, Cambodia, and Laos could then meet projected demand while lowering costs.

Vietnam could also help Cambodia to meet the need for rural electrification and build large-scale solar panels in a country where the land is much cheaper than in Vietnam. This would reduce the need for mainstream dams.

Eyler and Brunner can imagine regional cooperation going beyond this to suppress the illegal logging in Cambodia and Laos that feeds Vietnam's growing demand for timber to be used in the country's wooden furniture business. Vietnamese furniture companies earn billions of dollars in exports each year.

Grand environmental bargain?

Cambodia, Laos, and Vietnam could negotiate a "grand bargain" covering water and energy as well as the illegal trafficking of wildlife. The wildlife includes tigers and pangolins, among other animals.

As it is, Cambodia and Laos can't enforce their own laws regarding illegal logging and wildlife trafficking without Vietnam's active cooperation, according to Eyler and Brunner.

The two experts conclude that as the country with the most advanced economy in the region, Vietnam has the capacity to lead the negotiating process among the three countries.

In the meantime, some aspects of the weather and waters in all three countries appear now to be unpredictable regardless of how much they cooperate.

Take Laos, for example.

Radio Free Asia's Laotian Language Service reported recently that most schools have been closed in Laos's southern provinces because of heavy flooding. The country's Nam Theun 2 Dam discharged water beginning Sept. 2 but it was stopped on Sept. 5 because the released water combined with heavy rainfall began flooding 12 villages below.

So while one part of the Mekong might be experiencing drought, another has faced challenges caused by flooding.

The Mekong River Commission reported last year that climate change has injected an element of uncertainty into some of its projections.

One thing remains certain, however, and that is the melting of glaciers at the headwaters of the Mekong.

Long-term danger from melting glaciers

Looming over the Mekong River is a long-term threat coming from the headwaters of the Mekong in Tibet that sometimes gets lost in the discussion of the currently pressing threats to the river from both flooding and drought.

Although it's received little media attention, a recent report on the melting of Tibetan glaciers reveals long-term dangers which will eventually confront all of the downstream Mekong River nations.

It's been known for several years that these glaciers, which feed not only the Mekong but also rivers in India and Bangladesh, are melting more rapidly than ever before.

Radio Free Asia's Tibetan language service reported in June 2017 that a massive wall of water had roared through a village in Tibet's Sog County, washing away several houses and damaging others in an incident that local leaders blamed on melting glaciers.

The village chief said that the flood was likely caused by "excessive heat" linked to pollution and global warming that melted mountain glaciers.

On July 21, the American Geophysical Union based in Washington, D.C. published a report concluding that chemicals used in pesticides in the Himalayan mountains have been accumulating in glaciers and "are being released as Himalayan glaciers melt as a result of climate change."

Some of this pollution is now accumulating in lakes, and previous studies have shown that the consumption of fish found in such lakes can be destructive to human health.

Meanwhile, there seems to be a consensus among scientists that the Himalayan glaciers are melting at an unprecedented rate.

Dan Southerland is RFA's founding executive editor.

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