According to legend, in Kalyug, the Ganges, north India's holiest of rivers, will dry up, disappear or become invisible somehow. The disappearance of Ganga Maiyya, as we northies refer to her, will be a clear sign that we've entered a dark, dark age.
At Tehri, the invisibility has become visible - the water appears to be disappearing into aquifers, underground, instead of filling up the reservoir (at least, so says Sureshwar D Sinha, of Paani Morcha).
According to my sources, there are no fewer than 73 dams being built on various rivers, tributaries of the Ganga. There could be more. There's Tehri on the Bhagirathi. There are many more envisaged hydel power projects on the Bhilangana, the Bhagirathi etc. The dark age, then, is round the corner...
On a side-track:
One of the reasons that William Dalrymple's The Age of Kali is such a favourite with me (actually, I don't have a list of favourites. I do have a blacklist, though - the books I read and hated or never did finish, they were that boring, and which I consider my moral duty to warn the world against) is that it is such a curious translation of the Hindi word 'Kalyug'.
I always knew what Kalyug symbolizes - destruction, chaos, breakdown of all recognizable social and moral structures. But I somehow didn't associate all this with Kali. I'd always think of Lord Shiva when I thought of destruction. That the origin of the word Kalyug should be Kali...
But on second thoughts, why not?
Shiva has it made. It is Kali who needs the chaos, the breakdown of norms and mores. The Goddess has reason to complain. And it is perhaps time that she came into her own. And if it's going to be a dark-goddess-age after all, maybe that's not such a bad thing. Maybe the Ganges will disappear because she's had enough of being pure and maternal. It is tiresome being worshipped for all the wrong reasons, isn't it?