Future Melbourne apartment dwellers may trade unused rainwater from rooftop tanks with their neighbours, cutting down on their water bills.
South East Water is exploring a water-saving concept for Fishermans Bend in Melbourne's inner south, which would give up to 80,000 future residents a financial incentive to reduce their water consumption.
Called "rainwater micro-trading", it has never been attempted in Australia and is similar to solar energy systems, whereby households save on power costs by selling electricity back into the grid.
Development plans for Fishermans Bend stipulate that every residential building in the suburb must have a rooftop rainwater tank.
The tanks will serve two roles: to provide water supply to occupants, and to capture stormwater to reduce the risk of flooding from heavy downpours, which are expected to become more likely with climate change.
The proposal by South East Water is another way in which Melbourne's government-owned water corporations are planning for a drier future.