Climatological Notes
I was wrong about the Parramatta River fish ladder project. It seems what they’re doing is letting the river “fill” overnight, then letting it drain again during the day, as seen in these two photos, the first from this morning, the second from yesterday afternoon.

This must be a relief for the carp (some large ones are visible from overhead when the water’s low, and can be seen to struggle over ridges and weed clumps, looking for deeper pools), although the water fowl appear to benefit both ways. Of course, the benefits of the work may only prove effective for now.