A woman shows a glass with water which comes out of the faucets at her home in a poor neighborhood in Mexico City in this December 17, 2009 file photo. Mexico City, one of the world's biggest cities at 20 million people, has long struggled with a lack of water but the crisis worsened this year due to drought that has left reservoirs at record lows. Sudden cuts in the water supply are frequent and many residents know their water by the color it leaves the spout. Reuters Pictures logo Reuters Pictures 29 months ago

A woman shows a glass with water which comes out of the faucets at her home in a poor neighborhood in Mexico City in this December 17, 2009 file photo. Mexico City, one of the world's biggest cities at 20 million people, has long struggled with a lack of water but the crisis worsened this year due to drought that has left reservoirs at record lows. Sudden cuts in the water supply are frequent and many residents know their water by the color it leaves the spout.