Not a great indicator of environmental collapse, but a good one for a drought. I would imagine the people in charge of that artificial lake would love it if it would tide just a bit more at this point.

But I don't think they have as much control you suggest, I do believe they have obligations of letting amounts of water to go downriver for the farmers south of the dam.

I lived there for a number of years, the animated map does not do justice of showing how low the lake is, if you visit the dam you can see the water lines on the dam wall (hah!) and the shores around it. It's not just how much width the water has receded, but how deeply as well.