The Amazon effect: how deforestation is starving São Paulo of water

A drought two years ago triggered fighting, looting and official 'states of calamity' across the metropolis, with the army preparing to send in troops. Now, new warnings suggest it could happen again - and point to a surprising culprit

• O efeito Amazinia: como o desmatamento esti deixando Sio Paulo sem igua

Sio Paulo could face more devastating water shortages if farmers continue to clear the Amazon forest, warns the utility chief who recently steered the biggest city in the Americas from the edge of drought catastrophe.

Jerson Kelman, president of water company Sabesp, told Guardian Cities he felt a duty to speak out because he was a citizen as well as the head of a company who had seen firsthand how close this metropolis of 21 million people had come to a breakdown.