Costly and energy-inefficient, desalination was long seen as a measure of last resort for obtaining potable water—until about ten years ago, when Israel developed new techniques that have given it a water surplus. Rowan Jacobsen writes:
[T]he new Sorek desalination plant, the largest reverse-osmosis desalination facility in the world, [has proved itself to be] Israel’s salvation. Just a few years ago, in the depths of its worst drought in at least 900 years, Israel was running out of water. Now it has a surplus. That remarkable turnaround was accomplished through national campaigns to conserve and reuse Israel’s meager water resources, but the biggest impact came from a new wave of desalination plants. . . .
Desalination works by pushing saltwater into membranes containing microscopic pores. The water gets through, while the larger salt molecules are left behind. But microorganisms in seawater quickly colonize the membranes and block the pores, and controlling them requires periodic, costly, and chemical-intensive cleaning. But [Israeli engineers] developed a chemical-free system using porous lava stone to capture the microorganisms before they reach the membranes. It’s just one of many breakthroughs in membrane technology that have made desalination much more efficient.
Israel now gets 55 percent of its domestic water from desalination, and that has helped to turn one of the world’s driest countries into the unlikeliest of water giants.