Keeping native (freshwater) turtles as pets requires special care and is subject to permit or licensing restrictions. These vary between states and territories so you need to contact your state/territory government (the Department of Environment or its equivalent) to find out what restrictions apply.
The Australian Freshwater Turtle forum has information on permits and the care and husbandry of turtles:
http://www.australianfreshwaterturtles.com.au/index.php
As with all pets, we recommend you do plenty of research before you consider taking on a turtle. Turtles require special care and live for many years, so deciding to have one as a pet is a big commitment. You also need to ensure that you obtain your turtle from a reputable breeder and make sure that it has not been taken from the wild (this is illegal in most States).
This website provides general information which must not be relied upon or regarded as a substitute for specific professional advice, including veterinary advice. We make no warranties that the website is accurate or suitable for a person’s unique circumstances and provide the website on the basis that all persons accessing the website responsibly assess the relevance and accuracy of its content.