Hopes that environment-saving water will be delivered through the Murray-Darling Basin plan are evaporating rapidly.

Just two gigalitres of a promised 450GL have been delivered so far. The federal government is set to table the much-delayed Water for the Environment Special Account (WESA) report when parliament sits in just over a week.

The Australia Institute and the Greens say further water buybacks – which were capped under the Coalition – are the only way to get the water needed to sustain the basin, but that would require legislation.