Bush Heritage staff Joss Bentley and Stuart Cowell and researchers James Fitzsimons, Viki Cramer, Katriona Hopkins and Susan Jungalwalla have contributed to this article.

Choosing the right site for an environmentally friendly dunny might seem straightforward, as might the revegetation of an old quarry site, but this is not always the case. Environmental variables often combine to make apparently simple land management decisions anything but simple.

Rock type, weathering, soils, slope, sun, fire, water, wind, living things and human impacts all interact to mould the variety of landscapes around us. And these moulding forces continue to operate, despite our desire to work, or even our belief that we work, in a stable environment. In making effective land management choices, therefore, we need to understand these dynamic processes and their interactions and work in sympathy with them. Only then will we be successful in our long-term land management and not waste precious resources. This understanding requires knowledge and knowledge requires research.

The types of research needed on Bush Heritage reserves are as different as the reserves themselves. Staff and volunteers undertake much of the work, but on more complex issues we are increasingly working with research institutions. The skills and resources which they can bring are invaluable. Take the environmentally friendly dunny at Erith Island as an example.

FIGURE 1: Buffer zones on faults, cliffs and soaks at Erith Island.

FIGURE 2: Siting options for the dehydrating toilet.
The arrow indicates the final resting place for the toilet.

Erith Island has many visitors during summer with campers and ‘yatchies’ on the island over a number of months. The lack of any toilet facilities meant unpleasant health and environmental consequences. The steep, rocky, wind-swept terrain, the free-draining soils and the large quantities of waste deposited over short periods of time, created challenges for resolving the problem. Students from the University of Tasmania studying Geographic Information Systems (GIS) examined the environmental and social factors that would influence the effectiveness of four different types of toilets in different locations. Proximity to landing sites, cliffs, fault lines and wet areas (where there is a risk of groundwater contamination) (Figure 1) and the effects of wind, sun, substrate and vegetation height were all assessed. With this information the students identified ‘zones’ where different types of toilets would be more effective (Figure 2).

The result was the installation of a ‘dehydrating’ toilet, in a ‘zone’ where it was easy to use and maintain and where the dehydrating effects of wind and sun were maximised.The prefabricated toilet housing, designed by the University’s Architecture School, ensured visitors a pleasant experience by providing good light, ventilation and a great view. This guaranteed that the toilet would be used and the negative environmental impacts minimised.

Left: Unloading the prefabricated dehydrating toilet. PHOTO: BARBARA MADDEN

Above: Erith Island landing bay. PHOTO: BUSH HERITAGE