From the Murray-Darling system to Great Artesian Basin, 'invisible' underground groundwater is often the only water supply available across the vast majority Australia where its annual contribution to GDP is estimated at more than $6.8 billion a year. However, overuse of groundwater during droughts and aquifer depletion has already seen water crises, including in Australia's 'food bowl' the Murray-Darling Basin (MDB), California and Cape Town in South Africa, with more likely to follow with groundwater management largely reactive and unlikely to avert more crises as climate change accelerates and populations grow.