Along the banks of the Godavari River, near the city of Rajahmundry in the eastern India state of Andhra Pradesh, stands a museum built in the memory of Sir Arthur Thomas Cotton. As commissioner for irrigation there in the 1840s, Cotton brought water to Andhra’s parched lands, turning them into India’s rice bowl.

An engineer in the East India Company’s army, he did this by restoring and expanding an ancient network of dams and canals along India’s great southern rivers: the Kaveri, the Krishna and the Godavari. Motivated by a belief that science would pave the way for rural capitalism, he envisaged a landscape transformed.

And so it was.

But his dreams didn’t stop with those projects. In the 1870s, Cotton proposed building a series of canals to connect Himalayan rivers to the southern tip of India and another to connect the Brahmaputra with the Yangtze through Assam and Yunnan. A stingy British colonial government dismissed his plans as unrealistic. Nearly 150 years later, the dream persists. It is like a ghost behind contemporary India’s plan to link some of its biggest rivers, at an estimated cost of nearly $90 billion.

India is not alone in its ambitions. Hungry for energy and threatened by an acute shortage of fresh water, other Asian nations are competing to harness the power of the Himalayan rivers, on which more than half a billion people depend directly for sustenance.