A salty problem that won't go away

"There was nothing down there. Dead trees arched along the dry river-bed and, in the long-abandoned irrigation canals, frosty salt crystals climbed in towers and minarets. The ruined western highway crumbled at its edges and the helicopter blades whisked more bits of it back to dust."

– Gabrielle Lord, Salt (1990)

Earlier this year, the Australian Dryland Salinity Assessment 2000 was released as part of the National Land and Water Resources Audit. The assessment shows a spreading salt plague breathtaking in its extent and sobering in its potential to literally change the face of the nation. Next to land clearing and climate change, it is the greatest environmental challenge facing Australian civilisation this century.

The full consequences of this national emergency are yet to be fully realised by key decision-makers. Indeed, most Australians remain unaware of just how bad we have let the situation become – or how much worse it will get without major changes. Nearly six million hectares of land are already salt damaged, and many rivers and streams are highly loaded with salt. The monetary cost to farming and damage to built infrastructure are estimated to be up to $2 billion annually and rising fast.

Not a State or Territory in the country is left unaffected, and the myth that Queensland – where land clearing, the primary cause of salinity, continues apace – will be left unscathed has been totally dispelled.

Salt scalds are popping up in Sydney’s western suburbs too, while taxpayers in Wagga Wagga are already forking out more than $3million a year to repair and replace salt-damaged buildings, playgrounds, gardens, footpaths, pipes, and industrial equipment.

By the time the landscape reaches equilibrium, more than 17 million hectares will have succumbed to the salt – an area more than twice the size of Tasmania. The assessment is a wake-up call to all Australians.

Salinity Threatens Whole Ecosystems

Native bushland, national parks, reserves, wetlands and wildlife are often not accounted for in the litany of salinity damage. Ecologists are concerned that salinisation is not yet recognised as a key threat to species survival and ecosystem health.

A string of more than 200 wetlands lie in the path of the crisis. Within only a few years, for example, the Macquarie Marshes, wetlands of international significance, are set to become a saline wasteland, and at least half the native vegetation in South Australia’s Chowilla wetlands will be lost.

A recent biological survey of Western Australia’s wheatbelt by the Department of Conservation and Land Management indicates that some 450 plant species endemic to the region (ie. found nowhere else on Earth), are at risk of extinction in the next 25 years as a result salinisation. Hundreds more are subject to ‘genetic erosion’ as local populations are destroyed – bringing them closer to the edge of extinction, perhaps to be tipped over by climate change.

Salt damage to their habitat might see only 16 of the region’s 60-plus waterbird species persist in the years to come. Overall, the richness of animal species in the wheatbelt will be reduced by a third.

In most parts of the country, however, the full impact on our native plants and animals remains largely unknown. We do know that even quite low salinity levels can have a detrimental effect on freshwater communities. Moreover, salinity may be affecting ecological communities in ways that are not immediately obvious.