In Bolivia climate changes are also a question of population growth and poverty. At last survey, in 2001, the poor city of El Alto had a population growth of 5.1% a year. Old and used pipelines are the reason why as much as 50% of the water in El Alto leaks away and never reaches the consumer. There is not enough water for everybody so the authorities ration the water supply by adjusting the water pressure. Depicted: A car wash in El Alto.