Australia — Flows into the Murray-Darling river system from major Victorian tributaries are likely to deteriorate this year as the impact of major bushfires begins to translate into reduced water yields.
The prediction by Sydney University professor Mark Adams comes as the stricken mouth of the Murray faces new lows, with popular South Australian tourist town Goolwa warned that its stretch of the river could be dry for the first time.
Bushfires have a big impact on the amount of water drawn from forests, as the regrowth that replaces old trees typically requires much more water to grow.
North-eastern Victoria was hit by significant fires in 2003 and the summer of 2006-07.
Professor Adams said regrowth from those fires would soak up increasing amounts of water.
“The regrowth is already using as much water as the mature forests, and its trajectory is that it will use a lot more in the next few years,” he said.
“Dartmouth Weir, the Ovens River, the Kiewa, the Murray, are all going to see reduced water in them as a result of that regrowth unless we start a program of active forest management.”
Professor Adams, who has studied Victoria’s alpine forests, said the inflows could be reduced by 10 per cent.
Water authorities for those regions agreed the fires would inevitably lead to regrowth and increased water consumption but said it would be difficult to quantify Professor Adams’ predictions.
A spokesman for the Murray-Darling Basin Authority said planning was based on flows in a worst-case scenario, “which currently includes inflows lower than those experienced in 2006-07.
“Effects of the 2006-07 bushfires would be covered by this planning.”