Climate change and China’s huge dams have fermented unpredictable wet and dry seasons and upset fish spawning in the lower Mekong River Basin.

Water levels along Thailand’s section of the Mekong have plummeted to frightening lows, causing hardships to fishermen and farmers living along the storied waterway.

In northeastern Nakhon Phanom Province, water stands at a mere five meters, more than eight meters below the spillover level, local officials have reported.

The fact the Mekong is so low during rainy season is especially disconcerting. And it’s worse along four main tributaries in Nakhon Phanom where water levels have plunged to between a fifth and less than a third of their usual depths at this time of year.

The Mekong is a vital water source for tens of millions of people in several countries, which now are facing ecological disasters and everyone knows what is to blame: China’s hoarding of water for the reservoirs of its hydroelectric dams upstream.

Beijing frequently pays lip service to the need for sustainable development, but Communist Party leaders have been creating anything but sustainability with the Mekong, which it clearly sees as its own property to trifle with, other countries be damned.

By building a cascade of large dams upriver in recent years, China has been dealing a death blow to the Mekong downstream.

Environmental experts have been warning for years that the days of the Mighty Mekong are numbered because of Chinese energy policies that have failed to take into account the ecological costs of rampant dam building on the upper reaches of the river.

David Stilwell, the United States’ assistant secretary of state for East Asia and the Pacific, recently dispensed with usual diplomatic niceties and straight-up accused China of subverting the Mekong “for its own profit” and doing so “at great cost to downstream nations” of Thailand, Myanmar, Laos, Cambodia and Vietnam.

However, some of those supposed victims have contributed to the parlous state of the river. Laos, for one, has built large dams of its own with investments from China and Thailand and the country is planning even more.

Vientiane’s spending spree on infrastructure, however, has plunged the country into financial crisis, with China set to take over the country’s power grid.

Predictably enough, Beijing has shrugged off all criticism, blaming the chronically low levels of water on climate change and prolonged droughts. But droughts alone do not account for constant water shortages along the river, experts stressed.

For the second consecutive year the Lower Mekong Basin has seen water levels drop to record lows. Irrigation, rice production and fisheries all have been affected, threatening food security for tens of millions.

Numerous aquatic species from fish to turtles also have been impacted.

The Mekong Basin is “the world’s most productive freshwater fishery, accounting for over 15 percent of global annual freshwater fish catch,” explained four environmentalists in a recent article. “Meanwhile, (the World Wide Fund for Nature’s researchers) estimate that the contribution actually accounts for a quarter of the world’s freshwater catch.”

Beijing’s “efforts to restrict the (river’s natural) pulse in the name of ‘flood control’ threaten the livelihoods of tens of millions of farmers and fishers downstream,” the experts noted. “The only beneficiaries of such restrictions are dam operators and electricity markets upstream in China.”

A longer version of this article originally appeared in UCA News, a Bangkok Herald partner