Thank you @KimberiRP, makes sense as it's right on edge of a creek in an area that pools/ doesn't run. Seen them a few times but it was cool this afternoon so this one didn't escape me!
Limnichidae are very small (1-2 mm at most) and more convex than Psephenidae see https://biocache.ala.org.au/occurrences/8fdfb8dd-72f3-4997-b17f-159532432098