Hi Gabriel (and Omar),
Thank you Omar for sharing that info and helping out! Much appreciated.
Thanks for your question Gabriel – as Omar has suggested, refer to your university guides that will help you determine whether a source is credible or not. A quick search has brought up this one from Curtin University where you study, for example, but there will be others: https://libguides.library.curtin.edu.au/c.php?g=909870&p=6553318
Generally speaking, government sources are very reliable, and local government sources mostly can be relied on for up to date information (such as shires and land councils). They seem like a good place for you to start. For Design Area 3.3 about tourist shelters, you might also like to search for existing tourist accommodation operators and reference what types of shelters exist in the area already. These operators would be less credible for statistical information, however they would be suitable to reference as an example of shelters that exist in the area.
Hope this helps! Perhaps ask your lecturer/tutors if you have more questions about credible sources.
Best of luck,