But the commission — which counts the governments of Laos, Thailand, Vietnam and Cambodia as its members — can only disseminate news if someone informs it. One rights group in Nong Khai was told that the Thai department of irrigation is the body in charge of notifying villagers about the dam’s flow, but government officials denied that.
The Thai electrical authority, which is buying Xayaburi’s power, and the dam operator, which is backed by Thai investment, have pointed fingers at each other. Neither answered questions about the dam’s operations.
“The Mekong had dried up and still no information has been provided until today,” said Chainarong Setthachua, a lecturer at Mahasarakham University in northeastern Thailand, who has been studying the Mekong for 25 years
Mr. Eyler, the author, said the silence is probably intentional. “It’s likely that this lack of communication is purposely designed,” he said.
With the Mekong’s nutrients diminished and water flows unpredictable, farmers have increased their use of chemical fertilizers and pesticides, which are costly and harmful when used in excess, agricultural groups said.
Mr. Buorot said he used to reserve chemicals for the tobacco that he sells but now must douse even the vegetables his family eats.
“I’m worried about our health, but it’s the only way to get things to grow,” he said.
Last year, a Thai sand mining company approached officials in Ban Nam Phrai, Mr. Buorot’s village, asking for permission to scoop out the riverbed. Sand from the Mekong, used for land reclamation and as an ingredient for concrete and asphalt, has helped build Asian metropolises, from Singapore to Ho Chi Minh City, further eroding the river’s ecosystem.