A crisis is looming over water shortages worldwide. By 2025 more than half the nations in the world will face freshwater stress or shortages and by 2050 as much as 75 percent of the world’s population could face freshwater scarcity.

So say Mike Hightower (6332) and Suzanne Pierce (6313), Sandia water experts, in an article in a recent issue of Nature.

“This growing international water crisis is forcing governments to rethink how they value and use and manage water, especially because economic development hinges on water availability,” they say. “Drinking water supplies, agriculture, energy production and generation, mining, and industry all require large quantities of water. In the future, these sectors will be competing for increasingly limited freshwater resources, making water supply availability a major economic driver in the 21st century.”

Freshwater withdrawals already exceed precipitation in many parts of the US, with the worst shortfalls often in areas with the fastest population growth, particularly in the Southwest. But this is also very much a global problem.

What can be done to help solve the water dilemma? The answers are not simple, say Mike and Suzanne, and will involve usage of all water sources — more than just freshwater supplies as has been the primary focus in the past. Innovative treatments will have to be used — treatments using advanced membrane separation technologies, as well as treatment of nontraditional water sources such as wastewater, brackish groundwater, seawater, and extracted mine water.

Mike and Suzanne say that to some extent this is already happening. In the United States, wastewater reuse is growing by 15 percent per year.

“There are other, cheaper ways to increase water productivity, such as improving water conservation and efficiency,” Mike and Suzanne write in the Nature article. “But water reuse can help to expand these traditional approaches by matching the quality of water supplies to needs, and substituting nontraditional water for freshwater where appropriate.”

As an example, wastewater, seawater, or brackish groundwater could be used by electric power plants for cooling and processing instead of freshwater. Another example: Power plants could begin switching to renewable energy technologies that do not need water for cooling, such as wind and solar electric; and introducing technologies to condense evaporation from cooling towers and capture and reuse the water.