Can timber and water resources be sustainably co-developed in south-eastern New South Wales, Australia?

Abstract

In the south-east of New South Wales, Australia, forested catchments are largely relied upon to provide high-quality surface water at low cost to small regional communities. The forests in question are used for multiple purposes including timber production, which can result in conflicts and debate regarding the sustainability of timber and water resources being co-developed. A case study is examined where a logging operation will occur on 3.5% of the Myrtle Creek catchment that is used to supply water to the small township of Wyndham. Modelling based on the water yield response of eucalypt forests to disturbance predicts that during the first four years post-harvest, total streamflows will be increased under the '2010 logging' scenario, with a maximum increase of 2.6% within the first two years. Streamflows will then likely decrease compared to the 'no logging' scenario and will continue to do so until regrowth reaches 28 years of age with a maximum 1.4% decrease predicted. Streamflows under both scenarios will continue to increase over time as water yield has been suppressed by forest regeneration following extensive wildfires and logging that occurred from the 1960s to 1980s. It is concluded that timber harvesting, if limited spatially and temporally, can occur without compromising catchment values and may contribute to improved forest heterogeneity and resilience. However, in the face of a changing climate and an increased likelihood of catastrophic high intensity wildfires, the future sustainability of undercapitalised small town water supplies reliant on a single water source is questionable.