Great news on the information front:
China and Laos can no longer hide behind lies and misinformation when it comes to the impact of their megadams downstream. The Mekong Dam Monitor, hosted by the Stimson Center, gives highly accurate satellite imagery snapshots of the Mekong, updated regularly. These snapshots assess water levels in megadam reservoirs in Yunnan for instance, during different seasons, and assessing exactly how much water is stored or released.
You can filter out specific aspects you want to look at on interactive maps on the Stimson Center website: https://www.stimson.org/project/mekong-dam-monitor/