The calculations used to draft the Murray-Darling Basin Plan failed to account
for the impacts of climate change on water.
Scientific climate models conclude that the impact of a warming climate on the Murray-Darling Basin will be in less rainfall falling in different rainfall patterns, increased evaporation rates, and less runoff flowing into rivers and wetlands.
This means less water overall and more extreme droughts and flood events.
The Problems
The Murray-Darling Basin Plan was developed using average inflows over 110 years, but crucially ignored scientific evidence and modelling of dramatic reductions of inflows due to climate change.
This effect of this was to distort the reality of water availability and minimise the amount of water that would be returned to rivers and wetlands. The exclusion of climate change data and modelling was pushed by the Coalition governments and the irrigation industry.
Scientific data from the CSIRO has found a huge fall in inflows to streams, rivers and dams across the Murray-Darling Basin over the past 20 years.
Recent modelling found actual infows of water are just half the amount used in the development of the Plan.
The Nationals are pushing new dams as an answer to a drying climate. Dams do not make it rain, they are environmentally destructive and will reduce natural flows even further.
The Solutions
The 2024 review of the Murray-Darling Basin Plan must include the impacts of climate change — both already observed and modelled into the future.
Water management must take a hotter, drier climate into account.
More extreme rainfall patterns should be accounted for in the Plan and water recovery targets should be increased dependent on climate modelling.
Abandon all proposals for new and enlarged public dams in the Murray-Darling Basin.
