India hates China, especially over the border issues and China's close contacts with another Indian hate figure, Pakistan, so they are going to turn anything China does into a major crisis.
China needs dams like the whole world needs dams to generate clean electricity, not doing so means more coal and gas power stations; CO2, pollution, climate change etc.
Filling a dam initially results in reduced water levels down stream but when it is full, when the rains come, water has to go somewhere and guess what, it goes down stream again. You cannot weaponize a dam unless you blow it up to flood those down steam and the close surrounding Chinese lands, not a good idea.
Threatening to 'turn the water off' will not work because the dam overflows causing massive devastation locally as well as threatening the integrity of the dam itself.
Indian Monsoon waters, wasted, as well as having has huge rivers from Himalaya waters, but allows it to flood vast areas when downfalls occur, wasteful and instead of condemning China should do what they are doing.
Indian commentator spreading lies about "China virus", covid Chinese! Indian and US leaders in same boat, do not like Chinese!