Water supplies in south-west ‘at risk’ from logging

Claire Miller: Environment Reporter, The Age (article), 24/6/2000

As young trees absorb and release more water into the atmosphere than mature forests, logging the Otways so regularly could affect run- off from catchments that supply more than 250,000 people.  Water is already a critical issue, with Geelong on restrictions since January last year. The warning is contained in a report by the Otway Ranges Environment Network. It is based on a five- year study by the Cooperative Research Centre for Catchment Hydrology, which found that run-off into dam catchments declines when trees are young, then progressively increases, levelling off after 240 years.

The study, based on the Maroondah dam catchment, which is surrounded by mountain ash forests, indicates that the water yield would fall 25 to 33 per cent if forest was felled every 80 years.

Logging is among activities banned in areas supplying 90 per cent of Melbourne's water so that water quality and quantity can be preserved.

About 40 per cent of the Otway forests are in timber production zones managed by the. Department of Natural Resources and Environment. Many of the zones are also town water catchment areas.

The Otway Ranges Environment Network has relied on the Maroondah catchment research because a .similar study by the department in the Otways was abandoned in 1994. A spokesman for the Otways' network, Mr Christopher Tipler, said the Otways were the key catchment in the region.

Mr Joe Adamski, the executive manager of strategy and technology for Barwon Water, which services Geelong, the Bellarine Peninsula and the Surf Coast, said two years of drought had depleted storages.

But Mr Bob Caraill, chairman of the Corangamite Catchment Management Authority, which covers the Otways, said environmental, economic and social factors needed to be resolved, and the authority wanted the issues clarified as part of the Western regional forests agreements (RFA) process.

The Conservation Minister Mrs Marie Tehan, attacked the credibility of the Otways report, and one by the Wombat Forest Society, which analysed departmental figures to conclude the forest near Daylesford is being over-logged. She said there would be "proper, objective analysis" of concerns during the RFA process, to finish by 31 December.