Nepal, June 7 -- The water at Sundarijal knew nothing of the valley. It simply fell.

Madhu contained its power for two years in an old stone mill scented with iron, wood, and dust. She did not build for herself. She built to keep a small fire alive in an empty place.

The water thumped the mill wheel, spinning a water generator. Inside the mill, circuit boards rested on wooden planks, arranged so that the water's roar grew loudest when the river ran hardest.

The micro mill sat quietly, out of sight and forgotten by city officials, far distant from every power line. One board held lessons for the village kids-math, soil science, even a recording of a young girl reciting her first poem. Another board was covered with notes on the weather ...