INTRO

Unlike some rivers elsewhere in the world that are all virtual drains for all sorts of waste, the Murray River has not been used as a dump for industrial or chemical run-off. The government management ideas has consistently worked towards minimising pollution in our precious river, so we hardly ever have problems with chemicals being in the Murray. The River Murray is one of the least polluted river systems in the world.
The main pollution threat to the River Murray is excess amounts of substances that occur naturally in the river - salt, and clay particles in suspension, which scatter light and cause the water to become murky or turbid. Together with run-off of nutrients from fertilisers, detergents and sewage, increasing salinity and high turbidity are the greatest pollution problems in our water supply from the Murray.
Other things do pollute the River Murray. Stormwater collects pollutants and washes them into the river. Blue-green algae contain toxic compounds that can kill stock and cause health problems for humans. Litter is dumped in wetland areas or is left lying on the riverbanks to be washed into the river with overflow. However, these pollution problems are relatively minor and can be handled simply in comparison with the more complex and expensive management needed to combat salinity.

Pollution in the river affects us by decreasing the uses to which water from the Murray River can be put and it increases the cost of that water. For example, we have to step up water filtering as the water becomes more polluted. Stock and equipment need to be moved away from water contaminated by blue-green algae growth. This is expensive and puts a strain on other resources like grazing land. As pollution increases, the cost of cleaning up our water supplies rises. And in the driest state on the driest continent on Earth, we don't have too many alternatives for fresh water in South Australia. So, as you can see, pollution of this valuable river affects us all.

Some of these problems can be fixed by…
· Salt, can be controlled by improving irrigation efficiency, replanting and protecting native scrub, intercepting salty underground and drainage water.

· Nutrients in the River Murray are reduced by diverting run-off away from the main channel into wetlands that act as water filters for nutrients. Artificial wetlands created at the edge of dairy pastures absorb and use nutrients in run-off from these pastures. Conserving and improving natural wetlands along the river helps to prevent nutrients from building up.

· Stormwater is diverted to ponds before it flows into the river so that pollution can settle out. This takes about two days. Clean water is 'skimmed' off the top and flows on to the River Murray.

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