In pictures: Cities without water

Bolivia's capital city La Paz sits in a bowl high in the mountains of the Andes. It could be the world's first capital to run out of water.

Much of the city's water supply comes from the glaciers, which are shrinking each year. Scientists say many of the lower glaciers will disappear within 15 years.

The reservoirs that feed La Paz and its twin city El Alto are dangerously low after a long drought. Bolivians say there is less rain and the weather patterns are more unpredictable.

This one tap is shared by 80 families in El Alto, the slum city high above La Paz. The water trickles out slowly. "Some days there is none at all," Christian Muraga (13) told BBC News.