Murray River Drought Information

	Related Subjects
		A River worth saving
		Locks, Weirs & Dams
		Murray-Darling Basin
		Salinity: The problem
		River History
		Water Use & Consumption
		Water Saving Tips (website)
		Educational Resources

The Drought

Despite media reports of water restrictions across much of Australia the River Murray still has good water levels across the entire region and towns. Should the drought persist with little inflows to the catchment area the slow lowering of the Murray will occur to manage flow through the regions. Currently however it's a great time to visit the River Murray along the river yet precautions should be adhered to including snags and other potential hazards.

Drought Management

Source: Murray Darling Basin Commission

Why is the Murray-Darling Basin Commission (MDBC) running the river so high?

The high flows in the reaches between Yarrawonga Weir and Lake Victoria are needed to supply each state's water orders. Almost all of this water must come from the storage dams of Dartmouth and Hume Reservoirs as no water is available to the Murray from Menindee Lakes, and tributary inflows from the Darling, Goulburn and Murrumbidgee Rivers are very low.

Will the Dams empty?

Under continuing extreme dry conditions it is likely that the Commission’s three major storages Dartmouth Reservoir, Hume Reservoir and Lake Victoria will be drawn down to very low levels by the end of May 2007. This does not mean, however, that no water will be available for next year as any future releases from the Snowy Scheme and catchment inflows would still be available, albeit at very low levels if current dry conditions continue.

Will the Murray run dry?

No — certainly not this season. Currently, there is sufficient water in storage, including weir pools, to ensure the river continues to flow until next winter (07).

Is climate change to blame?

According to the Bureau of Meteorology “Australia and the globe are experiencing rapid climate change. Since the middle of the 20th century, Australian temperatures have, on average, risen by about 1°C with an increase in the frequency of heatwaves and a decrease in the numbers of frosts and cold days. Rainfall patterns have also changed — the northwest has seen an increase in rainfall over the last 50 years while much of eastern Australia and the far southwest have experienced a decline.”

It should be noted, however, that inflows in the first half of the twentieth century were generally less than in the second half and average inflows to the Murray in the last decade have been similar to the Federation and 1940’s droughts.

MDBC is collaborating with the Bureau and other agencies in a three year $7 million project looking at the potential impacts of climate change on the Murray-Darling Basin.

What about next season?

A repeat of 2007/08 next year is extremely unlikely in statistical terms looking at historical inflows. However the possibility of its occurrence is not being ignored and contingencies are being investigated.

How might the river be operated?

The big challenge in operating the River Murray under extreme dry conditions will be to minimise evaporation and transmission losses to make optimum use of available water.

A range of operational measures is being considered including the temporary lowering of weirpools, reduction of minimum flow targets and temporary disconnection of Lake Victoria during months with high rates of evaporation.

Drought drives down agricultural and household water use

Water consumption in Australia decreased by nearly 3,000 Gigalitres (GL), or 14%, between 2000-01 and 2004-05, largely due to drought, according to Australian Bureau of Statistics (ABS) figures released recently.

In 2004-05, water consumption in the Australian economy was 18,767 GL, with the agriculture industry consuming 65%, households 11%, water supply industry 11%, manufacturing 3%, mining 2% and electricity and gas 1%.

Of the 12,191 GL of water consumed by agriculture in 2004-05, dairy farming accounted for 18%, pasture 16%, cotton 15% and sugar 10%.

Consumption by agriculture in 2004-05 was down 23% from 2000-01 when it was 14,989 GL. Large falls in water consumption were in rice (from 2,223 GL to 631 GL) and cotton (from 2,896 GL to 1,822 GL), due mainly to smaller planted areas for these crops in 2004-05 compared to 2000-01.

Droughts in the Murray-Darling Basin

Source: Murray Darling Basin Commission

The River Murray system is fed mainly by rainfall over the inland slopes of the Great Dividing Range. Rainfall in the headwaters of the Murray falls mainly in winter and spring and is quite reliable. The Darling River drains the northern regions of the Murray-Darling Basin, where rainfall occurs more in summer and autumn from monsoonal winds, and is much less reliable.

Flow in the Murray in it’s natural state varied greatly from year to year and had a pronounced seasonal pattern. It peaked in winter and spring and was lowest in late summer and autumn. During times of drought the Murray was reduced to a chain of saline ponds. It has been reported to have stopped flowing between Tocumwal and Moama in 1850 and one could walk cross it a Echuca at times.

Today, flow in the Murray is more constant, but still retains a strong seasonal pattern. The extent to which the present flow pattern is different from the natural state varies along the river. Flow in the Murray comes from numerous sources. The most significan single source is the catchment of Hume Reservoir, which covers only 1.5% of the Basin’s area, but provides 37% of the total inflow during an average year and about 42% in a dry year.

Inflow to Hume Reservoir is boosted significantly by releases from the Snowy Mountains Scheme. The importance of these releases during dry years rivals that of runoff from the Hume catchment. During periods of drought well over half of the water commitments may be met by releasing stored water.

The Ovens and Kiewa Rivers in Victoria are also large contributors of flow to the Murray because their catchments receive high rainfall and there has been little development on these streams. The Murrumbidgee River in New South Wales is a significant water source in most years, but may only contribute small flows to the Murray during dry years due to the extent of regulation and irrigation development along the Murrumbidgee upstream. Inflow from the Darling River is extremely variable.

For more information

All these groups are committed and dedicated to educating and empowering the community to protect and manage the health of the River Murray and the Murray-Darling Basin and its surrounds. If you're interested in having your community group listed here please contact us or visit these groups who have drought information, services and support.