I found this little frog (35mm) when removing a concrete slab in my bathroom. It was one of at least two living in tunnels in the sand under four inches of concrete.
i believe its a spotted marsh frog with that line down its back, there is only a few of them that actually has a orange strip instead ot the pale yellow strip.
im not exactly sure of what type it is, but i also live in sa(eyre penisula) and they are very common here. every time it rains there must be hundreds out and about. and if you build a pond> THEY WILL COME lol.