There's another Australian state, Tasmania that also runs on 100% renewables, mostly hydro. There are plans to export more of that power to other states.

Hydro is pretty great with a few caveats. Flooding remain a massive problem if there is a failure, as the world most deadliest power plant accident was a hydro power plant with a death toll between 26,000 to 240,000 people. An other major issue is the extinction of species, as is currently occurring in Europe and especially in the northern parts. There are technologies to allow for migrating fish to bypass hydro power plants without chopping them to bits, through the effectiveness of the bypass tend to work against the power output of the plant.

100% renewable until the dams dried up and they flew in diesel generators (worse than coal) to prop up the state, reversing several years of environmental progress.

That event is illustrative of the fundamental problem here. Green energy proponents pretend it never happens and do not factor diesel emissions into the cost of hydro and other solutions.

Another common way they mislead is by pretending that emissions from gas peaking plants are not inherently associated with solar and wind generating, even though they would not exist without them.

It's a kind of sleight of hand or green washing that should be called out more frequently.

100% renewable does not exist. Not in '100% hydro' Tasmania or anywhere else.