A growing list of cities in the world are facing serious challenges in providing adequate freshwater to their residents. The United Nations predicts that by 2025, two-thirds of the world’s population may be living under water stressed conditions. Here are 10 cities in the world that are currently facing freshwater supply issues.

São Paulo
In São Paulo, Brazil a drought has left the reservoir system dangerously depleted in South America’s largest city. The Cantareira reservoir system is down to 7.1% of its capacity and could dry up in July if rainfall doesn’t increase.

San Diego
San Diego is spending billions on alternative sources of freshwater including desalination and wastewater recycling. San Diego imports 85 percent of its water supply.

Las Vegas
Lake Mead, America’s largest reservoir, has been drained by 4 trillion gallons and has fallen to record low levels.

San Antonio
San Antonio was found to be tied with San Jose, Lincoln, and Miami for the highest water vulnerability in the nation according to a 2012 University of Florida study.

In 2013 Beijing’s annual water consumption reached 950 billion gallons but only 554 billion gallons were locally available. A major challenge in China is pollution of rivers, lakes, and aquifers. Almost half of China’s water sources are polluted.

New Delhi
In the capital of India the water demand (1,100 million gallons per day) is outstripping supply (800 million gallons per day) while the population is expected to grow to 36 million by 2030.

Mexico City
With 22 million residents, Mexico City faces significant challenges in providing clean water to its population. An inefficient water infrastructure loses 40% of water before it reaches homes and depleted aquifers are causing the ground to sink.

Farms use up 85% of Egypt’s water while pollution of the Nile river and a desert climate is making water accessibility difficult.

As a small island, Japan has limited freshwater resources and Tokyo depends on rainwater harvesting to supply its 36 million residents with water.

Istanbul’s water reservoirs that supply its population of 13 million has shrunk dramatically to 22% of capacity as of July 2014.