On a summer evening in southern Mexico, a percussion group using water bottles as instruments leads a procession through Mérida, capital of Yucatán state. But one estimate suggests this could mean losing 1bn litres of water at the current rate of 2.6 litres for every litre of beer. Maya groups and UN experts have criticised consultations around the vast Maya Train rail project as exclusionary and inadequate. View image in fullscreen Construction of the Maya Train cuts through the jungle in Yucatán. View image in fullscreen Pedro Uc Be admits he does not know how to stop Heineken.