Our national action plan will combat the menace of salinity

Salinity, Australia's most urgent environmental problem can be defeated. It is most certainly not terminal. A variety of tools will be used in the successful battle with salinity in Australia.

The Australian Conservation Foundation (ACF) spokesman, Dr Stuart Blanch in the Weekend Australian 31/3/2001 hotly criticised the Murray Darling Basin Commission (MDBC) decision to allocate a further $60 million to the salt stream interception projects along the Murray/Darling Basin river system.

The ACF's criticism demonstrates a dangerous lack of understanding of the need and benefits of this process when Dr Blanch quotes the traditional ACF, one-size-fits-all solution, namely trees as the better solution to our salinity problem.

Modern aerial data technology is identifying major saline intrusions to the river system, originating at depths of up to 40 metres, well below the typical reach of tree roots and at the saline concentrations that would kill the trees were their roots to reach it.

This aerial magnetic data screening is now underway with country being flown by the specially equipped aircraft and the data interpreted in northern Victoria and Central Queensland.

Bore hole interceptions, especially in the Riverland of South Australia are already removing approximately 1,100 tonnes of salt per day, whereas trees remove no salt, just water.

Engineering is the method that has allowed the Dutch to farm the sea beds where tulips, not trees are grown for the simple reason they make more money.

The other important factor is that the interception process provides an immediate response and requires only a few square metres of farmland for its operation. Evaporation ponds must be created in a non farmland area, but my ambition is that new solar desalinisation technology will make it possible to use this upgraded water on farm or return the purified component to the river system. This could be the first contribution to sorely needed, but hard to resource environmental flows.

In terms of available river flows, it should be noted as confirmed by the ACF when it opposes the removal of old trees in forest production areas that vigorous regrowth of reafforestation reduces the run off to reservoirs or the river system by a typical 20% over the reafforested area.

Where trees are considered the appropriate salinity response, we must allow for reduced river flows when we are seeking more flows. Furthermore what ever the benefit, the trees will not remove salt, whereas the engineering solutions of pumping and drainage do.

Farmers in my electorate favour engineering as it has minimum effect on land use for cropping and regenerates land that would not support trees in its current state. Dryland areas have little capacity to grow trees for economic return and farmers object to having frequently to plant their most productive land to trees to soak up water re-charge.

Saline soil can be regenerated to production and salt levels actually reduced in our rivers. The principal ingredient to achieve this is cold hard cash to be spent by both land owners and government. Both need the revenues of agricultural production to support that expenditure.