From Oregon to Johannesburg, micro-hydropower offers a solution for drought hit cities

Cities worldwide are harnessing the power of gravity to generate electricity from public drinking water pipes

To see how closely water and energy are linked, you only have to look at the west coast of the US, where four years of severe drought have led to historically low levels in water reservoirs, forcing some hydroelectric plants to shut down or cut production.

It's little wonder, then, that new micro-hydropower technology that allows cities to generate electricity from the water running through their pipes is gaining worldwide attention.