Gujarat, India, has built solar plants on top of irrigation canals. The approach saves land and reduces water lost to evaporation from the channels underneath. A 1 MW pilot over a 750 m stretch of canal opened in 2012. It was followed by a 10 MW plant near Vadodara with 33,800 panels spanning 3.6 km of canal, which began generating power in November 2014. It is expected to save 16 hectares of land and prevent about 90 million litres of water from evaporating each year.
via India Builds Solar Plants atop Canals to Save on Land, Water | Scientific American