India's new mega-dam will roil lives downstream with wild swings in water flow every day

"Hey Rupam, open the door. Take this fish," a woman yelled from outside. I was sitting in the kitchen at my friend Rupam's house in rural northeast India. It was the heart of monsoon season, and rain had been falling since morning. The woman must have been shouting because the noise of the rain on the tin roof muted everything else.