Permanent crops and the Murray–Darling Basin. Karen Middleton

New documents reveal the Murray–Darling Basin is at risk of water shortfalls because of an increase in permanent crops, particularly almond trees. Karen Middleton reports.

Expanding almond plantations across the southern Murray–Darling Basin are increasing the risk that water entitlements cannot be met, even in years of good rain, according to a study conducted for the federal government.

Documents released under freedom of information laws warn that along with climate change, a shift to permanent plantings is contributing to the risk of shortfalls, due to these plantations’ location and the water they require.

In order to meet water needs, the study suggests options that include dredging or bypassing the Murray– Darling’s biggest bottleneck, the Barmah Choke, which sits on the border between Victoria and New South Wales, as well as a temporary moratorium on new downstream agricultural development while governments formulate a plan.

But it appears limiting or reducing plantations in the longer term is not being considered.

A review of the historical use of water between the Barmah Choke and the South Australian border says that as of last year, the expansion of nut and fruit trees had not actually increased annual water use overall because it was offset for now by less consumption elsewhere. But other documents in the 400-page FOI bundle suggest that will change as the trees mature.

The review shows that permanent plantings increased in area by 26 per cent between 2003 and 2018.

The expert panel’s findings warn demand for water is increasing and supply reducing, creating significant uncertainty over the next decade.

They say the risk of a delivery shortfall will increase due to clogging around the Choke, horticulture development in the Murray Valley, higher water demand as those trees grow and the requirement to deliver environmental outcomes under the basin plan.

“This is likely to be exacerbated under a drying climate,” a summary report says.

The move away from seasonal crops, such as rice and cotton, to fruit and nut trees has seen horticulture shift to downstream of the Choke, meaning water needs to travel further to supply the crops.

The Choke also restricts the transfer of this water, but the panel found the Choke’s capacity has been falling in recent decades – down 20 per cent since the 1980s.

Unlike seasonal crops, permanent plantings must be watered year-round, adding to peak-time pressure on the river system. The documents show the changes, including in climate, mean those peaks are also shifting, with demand now rising in September, not just through summer and autumn.

The expert panel was not asked to examine how much water is available, only whether available water can be delivered.

SA Centre Alliance senator Rex Patrick, who obtained the documents under FOI, says they confirm “there is a huge problem brewing ”.

“But instead of dealing with the root cause of the problem, the MDBA [Murray–Darling Basin Authority] only seem to be focusing on how to work around the problem by operating the river differently,” he told The Saturday Paper.

Patrick says the long-term impact needs to be more directly addressed.

“The growth in permanent plantations downstream of the Choke is unsustainable,” he says. “Existing and projected permanent plantation demand will push the downstream limits of annual water supply beyond what is actually possible, and at the same time kill off the diversity of crops upstream of the Choke.”

Patrick says certain crops are being favoured.

“The government’s philosophy of ‘water must go to the highest-value crop’ is free-market extremist stuff,” Patrick says. “It’s not achievable in practice and serves no one, other than almond barons and Australians who are satisfied with the idea of eating almonds morning, noon and night … It makes no sense to ignore the real problem with operating Band-Aids. That will just end in tears.”

NSW Nationals senator Perin Davey agrees that permanent plantings are a problem.

“While the water market is working economically and water is being purchased for highest value, is highest value best use?” Davey asks. “The risk is that we are going to reach peak almond and then when the almond industry recalibrates, as has happened with olives [and other crops], the collateral damage on the way is our broad-acre industries – rice, corn, wheat and dairy.”

Davey says water buybacks have seen farmers abandon good arable land with existing irrigation infrastructure, while “very thirsty” nut crops that use more water per hectare than rice or cotton emerge in more difficult downstream locations instead.

“This was the mistake of nonstrategic, open-tender buyback,” she says.

MDBA river management executive director Andrew Reynolds told The Saturday Paper there was “a real risk of a shortfall in the delivery of water to where it needs to be”.

“The MDBA is looking into options to manage this issue in partnership with the states,” he said.

“The approval of plantings is a matter for state governments in terms of development applications under state planning rules. The MDBA has no role in determining what water is used for.”

The basin council was due to

• discuss the issue late this week.