Greenpeace International has claimed in a new report that coal power plants worldwide consume enough freshwater to sustain one billion people.
Freshwater resources are expected to be depleted should several new coal power plants worldwide proceed with development, which could increase severe droughts, the report noted.
Greenpeace East Asia senior global campaigner on coal Harri Lammi said: "If all the proposed coal plants would be built, the water consumed by coal power plants around the world would almost double.
"We now know that coal not only pollutes our skies and fuels climate change, it also deprives us of our most precious resources: water."
There are currently 8,359 coal power plants in operation, which are consuming substantial amounts of freshwater.
Regions that are already running a freshwater deficit are set to receive a quarter of the proposed new coal plants and in these locations, called red-list areas, water is used faster than it is naturally replenished.
China (237GW), India (52GW) and Turkey (7GW) are listed as the top countries that have proposed additional coal plant capacity in red-list areas.
Almost half of the proposed coal plants in China are in red-list areas, while in India and Turkey the figure is 13%.
The International Energy Agency said the next 20 years will see coal accounting for 50% of the growth in global water consumption for power generation.
Greenpeace research shows that the consumption of water by coal plants will rise by 90% once they become operational.
Greenpeace International report lead author Iris Cheng said: "Governments must recognise that replacing coal with renewable energy will not only help them deliver on their climate agreements, but also deliver huge water savings."