More desalination is coming to Australia’s driest states – but super-salty outflows could trash ecosystems and fisheries

From around 1996 to 2010, Australia was gripped by the millennium drought. As water shortages bit hard, most of Australia’s capital cities built large seawater desalination plants – Sydney, Adelaide, Brisbane, Melbourne and Perth. Remote towns have also built smaller desalination plants.

Most cities didn’t actually use them much. The drought broke in 2010, and desalinated water is expensive. The exception is Perth, which has been hit by declining rainfall, a drying climate and overuse of groundwater. The city will soon open its third desal plant...