Repairing Australia’s inland river and groundwater systems: nine priority actions, benefits and the finance gap

Inland river and groundwater systems in Australia, as elsewhere, have been heavily overexploited, modified and degraded and are subject to increasing pressures from anthropogenic activities and climate change. Here, we propose the following nine priority actions to repair these critical parts of our landscape not currently being implemented or not at a sufficient scale: (1) riparian revegetation, (2) incentivisation to retire riparian farmland, (3) water recovery to achieve sustainable levels of take in the Murray–Darling Basin, (4) restoration of riverine connectivity through constraints management, (5) removal or modification of fish barriers, (6) installation of cold-water pollution device on priority large dams, (7) installation of fish diversion screens on all irrigation pumps, (8) capping of open bores and conversion of open bore-drains remaining in the Great Artesian Basin and (9) restoration of groundwater extraction in the Murray–Darling Basin to a sustainable level of take. We estimate the scale and costs associated with each priority action and synthesise evidence demonstrating benefits. We discuss the importance of enabling and supporting regional communities, especially Indigenous nations, to implement these actions. To implement the priority actions outlined here at the scale indicated, our estimates suggest approximate annual investment from 2025 to 2054 of A$3.1 billion (2022 dollar values). Riparian revegetation across 14.4 × 106 ha could sequester 1.6 × 109 tonnes of CO2, offsetting ~37% of Australia’s net emissions over the next 30 years by using high-integrity carbon methods. Revenue generated through the carbon market could cover between 37 and 72% of the costs, reducing investment needed to between A$0.9 billion and A$2.0 billion (2022 dollar values).