Solving Australia's Salty Problem
CANBERRA, Australia, September 5, 2000 (ENS) - Salt has been rising to the surface of the land surrounding Australia's largest river system - the Murray-Darling Basin - destroying the land for agriculture and wildlife. Part of the solution may lie in creating a new landscape which is a mosaic of commercial tree crops, mixed perennial-annual planting systems and areas of native vegetation.
Today two new initiatives to tackle salinity and other land degradation issues in the Murray-Darling Basin were released for a three month public comment period by the Federal Minister for Agriculture, Forests and Fisheries, Warren Truss.
The initiatives cover the management of water catchment and salinity in the Basin. The government hopes the public will not only make comments, but also get involved in changing the patterns of land use in the Basin to allow groundwater levels to fall, taking with them the killing salt.
"The Integrated Catchment Management Policy Statement proposes that valley targets be set for water quality, biodiversity, water sharing and the health of the Basin's river ecosystems," Truss said. Having targets means catchment managers have something tangible to aim at when they prepare their work plans.
Extending from north of Roma in Queensland to Goolwa in South Australia and including three quarters of the state of New South Wales and half of the state of Victoria, the Basin covers one-seventh of the continent and has a population of nearly two million people. Another million people outside the region depend heavily upon its resources.
The Basin contains more than 20 major rivers, including Australia's three longest rivers, as well as important groundwater systems. It provides fresh water for domestic consumption, agricultural production and industry.
In most years, the city of Adelaide draws more than 40 percent of its water from the Murray. During droughts this dependence increases to more than 90 percent.
Three wetlands in the Basin are recognised under the Convention on Wetlands of International Importance, the Ramsar Convention. At the time of European settlement the range of species included 85 mammals, 367 birds, 151 reptiles, 24 frogs and 20 fish. Now, the Basin has at least 35 endangered birds and 16 endangered mammals with 20 mammals being extinct.
The large, very shallow drainage basin covers more than one million square kilometres with only one exit flowing out of Lake Alexandrina in South Australia. Changing patterns of land use have groundwater impacts which are felt hundreds and even thousands of kilometres downstream.
The clearing of native vegetation has been a key element of rural development in Australia since the early 1800s. This has caused groundwater levels to rise rapidly as native vegetation that once took up the water disappeared. Water from the river system used for crop irrigation has leaked into groundwater, causing groundwater tables to rise in many areas. As the water rises, it brings with it natural salt stored in the soil.
The movement of salt towards the surface is taking place across all the major river valleys in the Murray-Darling Basin on a large scale. During the coming 100 years, scientists predict the annual movement of salt will increase two to three times. The salt load exported to and through rivers will double.
This crisis has brought the Basin governments to develop strategies that may contain salinity levels to meet the targets set by the new management strategy.
The draft salinity strategy was prepared by representatives from the six governments in the Murray-Darling Basin, and supporting strategies from NSW, Victoria and South Australia have been released in the past few weeks.
"It represents a long term commitment covering 15 years of programs. In the short term, it will employ engineering options, such as ground water pumping, to keep river salinity levels down until other solutions, such as tree planting and new farming systems, begin to take effect. Market driven incentives will also be an important part of the package," said Truss.
Today, farmers and land managers were offered a package of tactics for combating the rising salinity in the Murray-Darling Basin by the scientists from the Commonwealth Scientific Industrial and Research Organisation (CSIRO), a federal government branch.
At the CSIRO Discovery Centre in Canberra, Dr. John Williams, deputy chief of CSIRO Land and Water, offered his remedies during the launch of the Murray-Darling Basin Commission's draft strategies.
"No single land use option will halt the growth of salinity in our land and rivers. We need to employ a combination of novel land uses that suit the diverse climate, soils, and water conditions of the Basin. Many of these will require more research before they can be used by farmers," warned Williams
"These land uses, collectively, must allow no more water to leak past the root zone than does native vegetation," he stressed.
These low rainfall tree crops are potentially the most effective option to curb salinity, said Williams, but there is "urgent work to be done" to develop suitable varieties and ensure markets exist for their products.
Williams advised planting new types of cereals, pulses, oilseeds and forages bred to reduce deep drainage and nitrogen leakage. He recommended energy farming systems which combine current annual and perennial plants, the best agronomy, companion plantings, rotations and combinations.
Land managers will be able to take advantage of ways to pinpoint the best locations for tree crops, other perennial plants and high value annuals to meet targets for water quantity and quality. And there will be new tools to help land managers monitor water leakage past the root zone and change their land use patterns accordingly.
Williams advised immediate action. "The take-home message is - let's use the techniques we have for fighting salinity now, and let's make sure we have plans in place to develop all the new land use and farming options we will need in the future."
"We have to accept that we cannot protect everything," warned Truss. "We also need to work out the nature and extent of the contributions that will be required from all stakeholders - governments, landholders, conservationists and the wider community.
"That's why it's important to allow the public to comment on these two documents. We need to hear the ideas and concerns of all stakeholders. The community also needs to be reassured that decisions on how the Basin is to be managed are made in a fair and open manner," the minister said.
The bottom line was stated clearly by the Murray-Darling Basin Commission five years ago. "The amount of water presently taken from the rivers is not ecologically sustainable and a new balance between the environmental requirements and the consumptive use will have to be struck. This is essential for the long term viability of not only the aquatic ecosystems and rivers, but also virtually all economic activity within the Basin."
Copies of the draft Integrated Catchment Management Policy Statement and draft Basin Salinity Management Strategy are available online at the Commission's website: http://www.mdbc.gov.au