Stop logging Melbourne's catchments to save water

Letter to the editor

It is encouraging to hear that the announced desalination plant for Melbourne (Australian 20/6) will be carbon neutral. However the renewable energy it will consume would be better utilised supplying Melbourne which is now struggling for power during peak load times.

Following the doctrine that prevention is better than cure, the Bracks government should end all logging of our old growth forests and water catchments.

Considering the Thomson catchment, which supplies over 50% of Melbourne's water during drought years:

• Over 50% of the Thomson catchment has now been logged.

• The area most heavily logged produces 70% of the water.

• This is causing the loss of 20 gigalitres of water each year from the catchment, which amounts to the water used by about 100,000 households.

The image below shows the extensive patchwork logged forest in the Thomson catchment, circa 1995.



Around 90% of Melbourne's tap water comes from 157,000 hectares of native forest spread across our water catchments. These forests have the prime purpose of harvesting drinking water. Scientific studies have confirmed that logging causes the loss of at least 30 gigalitres from these catchments each year. These losses are equivalent to the current water use of 150,000 Melbourne households per year. Over the last 30 years a third of these catchments have been logged.

The value of the water lost subsequent to logging far exceeds the low value of the woodchips, timber and royalties. Victorians would be $147m better off per year if logging of catchments stopped.

Melbourne Water should buy out the timber licenses for the Thomson and Yarra tributary catchments at an estimated cost of $3.9 million, rather than spend the estimated $20 million to bring the Tarago catchment back into the domestic water supply system.

If the Bracks government were to stop logging our native forest, adopt further conservation measures and encourage every household to use a water tank, we may not even need the $5 billion desalination plant which will double the cost of water bills.

The UK Stern Report estimates that deforestation represents more than 18% of global carbon emissions, so protecting protecting our forests from logging has the added benefit of ensuring the carbon they store stays there and does not further contribute to climate change.

Links
City counts cost of logging, The Age