1. California: The state's water resources are at critically low levels and a drought emergency has been declared. The health department says 17 rural areas are dangerously parched.
2. Sao Paulo, Brazil: The country's largest city is on the verge of water rationing because of a severe drought and shortages are possible when the country hosts the football World Cup in the summer. January was the hottest month on record in the city and water in its main reservoir has fallen to 20.9 percent of its capacity — the lowest level in a decade.
3. Tehran, Iran/Middle East: The capital is facing a shortage so serious that officials are making contingency plans for rationing in an area where 22 million live as well as in other big cities. President Hassan Rouhani has identified water as a national security issue.