The results of the CSIRO survey into the Warrego River, the first of a series on the basin, was alarming because it suggested that more developed river systems, like the Condamine-Balonne, will face serious problems, according to Asa Wahlquist in The Australian (8/9/2007, p.5).
Water extraction to be halved: By 2030, climate change and water use will see a 7 per cent reduction in the amount of water that flows out of the Warrego, in southwest Queensland, into the Darling. Water extraction would have to be halved on the second-least developed river in the basin for the Warrego’s water-sharing plan, which specifies 89 per cent of its flows should reach the Darling.
Less than 12GL of private water storage along Warrego: The Murray-Darling Basin Commission reports there is less than 12 gigalitres (billion litres) of private water storage built along the Warrego, compared with 1333GL on the Condamine-Balonne. In 2005-06, 25GL passed through Cunnamulla on the Warrego, while the total flow through St George, on the Balonne, was 123GL.
CSIRO report result of Water Summit: The CSIRO report includes the eight gigalitres of Warrego water that the Queensland Government intends auctioning off. The report was commissioned by the Prime Minister’s Water Summit last November and is the most comprehensive report of its kind undertaken by the organisation. The CSIRO assessed current water use, including the interaction between ground-water and surface water. It also estimated future water use, looking at the impact of climate change and future developments like plantations and farm dams that would reduce stream flow.
Climate models variation: Dr Hatton said the best estimate of the impact of climate change on the Warrego was that it would reduce river flows by 6 per cent in 2030, leading to 7 per cent less water flowing into the Darling River. “It is important to appreciate there is variation among the climate models.” He said the hydrology of the 137,000-hectare Yantabulla swamp, and the water holes along the Warrego had not been affected by current development.
Lowest inflow on record last year: Last year, inflows into the Murray were the lowest on record, just 1211GL, far below the average of 11,100GL Assistant federal Environment and Water Resources Minister John Cobb said the report “underlines the incredible variability of the system”. He said the federal Government was considering buying the eight gigalitres to be auctioned on the Warrego.