In many areas of Australia, trees are dropping huge amounts of leaves. This is almost certainly a response to the ending of the drought in most areas. Native gum trees went into almost suspended animation during the drought: they froze.
At the end of the drought they are slowing going to rapid growth and are dropping the very old leaves that they kept during the drought.
The adaptive powers of plants never ceases to amaze me. But, you may be cleaning up heaps of leaves for some months yet.
Use the leaves as mulch or in the compost heap. If you want a lush, low maintenance garden, NEVER throw dead leaves away.
Retain all the green waste material on your land. It Pays Off!