An intergovernmental organization says water levels in the Mekong River have dropped to “worrying levels” since the start of 2021. The drop was partly caused by a restriction on flows from a hydropower plant in China’s Yunnan province, the Mekong River Commission (MRC) said in a recent statement. The MRC includes Cambodia, Laos, Thailand, and Vietnam. The important waterway has turned blue along the Thai-Laos border, from its usual cloudy brown color, signaling lower water and reduced levels of sediment. Lower levels of sediment could be the result of outflow restrictions from China’s Jinghong hydropower station, the organization said. The statement said other reasons for the drop were lower rainfall, flow changes upstream and hydropower operations in Mekong tributaries.