Then somebody forgot to tell
He Who Has Not Been Named about that; he drinks whenever the spirit moves him.
If that's a cactus in the lower left corner, I'd remove it—in general (some possible exceptions), succulents aren't compatible with chameleon habitats.
I'm not crazy about all the artificial plants, but IIRC, that's been covered.
Is it too much water that's killing the plants, or not enough full-spectrum light? (It looks dark to me, but that may just be the pic.)
Is there sufficient drainage? Some plants need to dry out almost completely between waterings; this is only one reason why plant choices have to be considered carefully and set up to survive—just as the enclosure has to be set up for the chameleon to survive.