10 May

This is Lake Eyre, our biggest inland lake (when full) and the third largest salt lake in the world. My father in law always says they should flood it with seawater. For years this sort of idea was tarnished by the loon schemes like the Bradfiled scheme, of turning the rivers inland. But with a climate emergency, the flooding of salt lakes worldwide is back in the engineering thought bubble. Because these lakes are below sea level (Lake Eyre is 15 metres below), a pipeline from the sea to the lake would flow naturally under gravity. That could then be used to generate hydroelectricity. The filled lake would generate all sorts of life in the area, as it does when the lake fills from rivers to the north when they flood. More of a saltwater environment, but that salt could also be extracted for a whole range of uses, including in batteries. It would also generate significant rainfall, through evaporation. And at a time when ocean levels are rising worldwide, there'd be no shortage of water from the main ocean to continuously refill it. It would help moderate that sea level rise, particularly if they do this worldwide with other salt lakes. It may be the sort of bold idea whose time has come.