Logging and Water

The water supply of the City of Melbourne begins in mountainous forests to the city’s northeast close to where Snobs Creek and the Rubicon Valleys lie. These valleys supply much of the fresh water of regional Victoria.

Over 50% of these hardwood forests contain the tallest flowering plant in the world – the Mountain Ash. Catchments that contain old-growth ash forests yield almost twice the amount of water each year as those covered with young forests aged 25 years. Put simply, older ash forests release more water back into the catchment.

Despite most Victorian residents wanting this current logging practices to stop, and despite the plethora of scientific evidence damning the practice of clear –fell logging, it appears that some vested interests (such as the CFMEU) and corporate industry interests (such as Vic Forest and the foreign owned Australian Paper Mills in the Latrobe Valley), are the reasons that the Andrews Government remains reluctant to take any action to stop it.

Under the Forest (Wood Pulp Agreement) Act 1996, the Victorian government is bound to supply Australia’s largest pulp and paper mill at Maryvale, owned by the Nippon Paper Group, with at least 350,000 cubic metres of native forest logs each year.

This is an unsustainable and unnecessary activity when recycling of paper product take its place.

Clear-fell logging has a dramatic and detrimental effect on water quality and water yield in catchments.
Re-growth trees in logged coupes require more water to grow subsequently releasing less water into catchments.
Research on forest hydrology shows that the amount of water yielded from mountain ash forests is related to forest age.
It takes approximately 150 years for water yields to return to their pre-logged status.
The loss in water yield in $ terms is far more than what timber yield brings to the Victorian economy. Research has shown that the water in these areas is 25.5 times more valuable than the timber and pulpwood from ash forests.
Logging of water catchments adversely affects water quality through increasing sediment levels as does road construction and traffic through logging coupes.
Since the 1940s, 45% of the catchment’s ash forests (including mountain and alpine ash forest) have been logged. There are plans to log up to a further 17% of these forests under the VicForest’s existing logging plan.
Continued clear-fell logging in Melbourne’s water catchments could reduce the city’s water supply by the equivalent of 600,000 people’s annual water use every year by 2050.
With clear-fell logging occurring approximately between a 60-120-year timeframe, large areas of ash forest are kept in a high evapotranspiration stage of growth, therefore releasing less water back into the catchment.
Traditional logging comparison to clear-fell Logging

**These facts were summarized from the following research paper ‘Resource Conflict Across Melbourne’s Largest Domestic Water Supply Catchment’ Resource Conflict in Forested Water Catchment 20181108.pdf