I didn't notice any white powdery coating. Now I have compared the photos with the Species page I see these phyllodes are multi-veined and do not have a prominent single vein. I did not see any flower buds, which would be expected for acacia flowering Aug-Oct. Maybe you have to suggest something else.
I undid my original suggestion (based on glossy leaves and general shape) of Acacia pycnantha but could not then suggest another ID on my iPad. Worked on my PC.