It's important to consider that Methane has a very short atmospheric half life, so that 1.3% becomes 0.06% in a few decades.

Moreso, this can be minimized.

In the end, it's clear that hydro, long term, is indeed clean, moreso than a battery+solar solution would be.

Indeed, this is 1.3% going to 0.06%, despite the fact that hydro represents almost 15% of global electricty generation.