The River, Lakes and Coorong Action Group (RLCAG) has sent out a probing questionnaire that asks candidates in the March 20 South Australian elections to answer 76 questions relating to the River Murray and the lakes at its mouth.
Results of the questionnaire, which was launched at a protest action on the steps of Parliament House in Adelaide on February 25, will appear online in the week before the elections.
In recent decades, the Murray has ceased flowing into the sea as often as one year in two. Diversions from the rivers of the basin, mainly for irrigation, mean that for long periods the SA section of the Murray has consisted of a series of near-stagnant pools.
Without taking measures to counter this, lack of flow in the river would allow seawater to back up through lakes Alexandrina and Albert and for scores of kilometres up the river itself.
This has been prevented since 1940 by barrages, obstructions built in the watercourse, near the Murray mouth. But while seawater invasions were once possible only during the worst droughts, low-flow conditions are now close to permanent. Often, the water surface in the lakes and lower reaches of the river is more than half a metre below sea level.
Below the barrages, the Coorong lagoon's environment has been transformed. Previously brackish, the waters of the Coorong once supported rich ecosystems, including an abundance of bird life.
Due to the lack of freshwater inflows, the southern part of the Coorong is now much saltier than the ocean — the ecosystems have collapsed. Elsewhere, the Coorong is shifting from a brackish to a marine environment.
Further up, the lakes are dying; Lake Albert is kept from vanishing completely only by pumping from neighbouring Lake Alexandrina. Studies reveal that for thousands of years the lake waters were generally fresh, but evaporation has now raised salinity to the point where freshwater ecosystems are severely stressed.
To reach the lake shores, local residents now have to cross stretches, often hundreds of metres wide, of drying black mud.
The response to the crisis by the state Labor government of Premier Mike Rann has been characterised by long periods of indifference, interspersed with bouts of political panic and rash, ill-thought-out initiatives.
Uppermost in the government's considerations has been the question of Adelaide's water supply. In dry years, as much as 90% of Adelaide's water is pumped from the Murray, and low river flows mean this source is threatened by rising salinity.
To secure Adelaide's drinking water supply, the government wants to build a weir across the Murray, where the river enters Lake Alexandrina.
The government's main initiative — sharply criticised by environmentalists — has been to build two earthen "regulators" across the arm of Lake Alexandrina, which leads toward the seacoast. RLCAG said that by cutting off areas of relatively low salinity, the "regulators" will speed the decline of freshwater ecosystems over most of the lake area.
Meanwhile, building a weir to close off the Murray from Lake Alexandrina could increase the danger posed to Adelaide's water supply by toxic algal blooms.
RLCAG's research has helped formulate its "Common Sense Community Action Plan". Elements of the plan are:
• no seawater, no more weirs;
• planting, mulching, liming;
• reducing diversions from tributary catchments;
• urging Adelaide to use water more wisely; and
• buying water for the environment.
The only longer-term solution, RLCAG argues, is for society to change its water use to the point where regular river flows are available to flush salt and sediments out to sea.
Will candidates in the SA elections bite the environmental bullet? Their responses, or lack thereof, to RLCAG's questionnaire will be public. It will be posted online and released to the media in the week before polling day. The SA Greens policy on water can be viewed here.
[More information on RLCAG.]