Desalination

Arizona is one of the fastest-growing states in the U.S., with an economy that offers many opportunities for workers and businesses. But it faces a daunting challenge: a water crisis that could seriously constrain its economic growth and vitality. A recent report that projected a roughly 4% shortfall in groundwater supplies in the Phoenix area over the next 100 years prompted the state to curtail new approval of groundwater-dependent residential development in some of the region’s fast-growing suburbs. Moreover, negotiations continue over dwindling supplies from the Colorado River, which historically supplied more than a third of the state’s water. The Colorado River’s watershed extends across seven U.S. states and into Mexico. Use of river water is governed by a compact negotiated in 1922. Center for Colorado River Studies, CC BY-ND As a partial solution, the Arizona Water Infras...

Coastal urban centers around the world are urgently looking for new, sustainable water sources as their local supplies become less reliable. In the U.S., the issue is especially pressing in California, which is coping with a record-setting, multidecadal drought. California Gov. Gavin Newsom recently released a US$8 billion plan for coping with a shrinking water supply. Along with water conservation, storage and recycling, it includes desalination of more seawater. Ocean desalination, which turns salt water into fresh, clean water, has an intuitive appeal as a water supply strategy for coastal cities. The raw supply of salt water is virtually unlimited and reliable. Ocean desalination is already a major water source in Israel and the United Arab Emirates. Cities in the Middle East, Australia, Mediterranean Europe, the U.S. Southwest and Australia also rely on it. There are more than 20 ocean desalination plants operating in California, plus a few in Florida. Many more plants acr...