Risks to inland water environments include direct risks (such as direct water extraction, or changes in run-off and recharge) and indirect risks (such as expansion of invasive species because of increased tourism).

Climate changes may produce both types of risks. Updated climate projections, including rainfall, were released in 2015. For northern Australia, models offer diverse results; natural climate variability remains the major driver of rainfall changes for the next few decades, with variable outlooks thereafter. There is high confidence in future increases in the intensity of extreme rainfall events, so the risk of extreme wet periods and floods seems likely to increase. In the rangelands, there is high confidence in long-term rainfall declines. The direction and magnitude of annual and summer rainfall changes are less certain, whereas the risks of extreme rainfall and time spent in drought will increase. For the southern and south-western flatlands, there is high confidence that winter, spring and annual rainfalls will decrease in both the medium and longer term, and high confidence that extreme rainfall events will intensify. For much of the Murray–Darling Basin, there is a mix of medium and high confidence that, by late in the century, there will be decreases in winter–spring ‘cool-season’ rainfall. Warm-season and summer–autumn rainfall is not projected to change significantly. In other parts of Australia—the south-east and Tasmania—there is high confidence in winter and spring rainfall decreases later this century, except for Tasmania, where there is medium confidence in increases in winter rainfall. There is also high confidence in future increases in the intensity of extreme rainfall events.

Risks from water resource development are ever present. Proposals for significant infrastructure development in the coming decades raise risks of interrupting natural flow regimes, affecting waterscape connectivity and impeding aquatic ecosystem processes that require the run of the river. Risks in developing Australia’s north include surface-water regime change, surface-water pollution, groundwater extraction, seawater intrusion, and accelerated spread of pest plants and animals. However, we have a significant body of practice and knowledge to help avoid the land and water management mistakes of the past.

A range of risks arise from current and proposed coal-seam gas and large coalmining developments, and these will be informed by the Bioregional Assessment Programme.