Perth has quite a few of them. I did a truck run out there years ago and spent a few days chasing up drains. There's a whole series of them west of the airport on the south side of the river in the suburbs, starting from a small creek about 1km inland. More elsewhere. There are a couple that drain the northern beaches but which exit in small pipes to the sea so you never ever want to be in them for any reason. There a nice one to the east of the city that has a very tidal entrance (hence we called it Very Tidal) and goes on for a few Km with an easy exit manhole near a main road. It goes on further than that and is supposed to have a connection with another drain but the connecting pipes are all too small to do anything but wiggle through so it's not worth it.
Most of the Perth drains are still overland creeks, not concrete canals like in the east. So quite nice from an environmental and scenic point of view, but not from a UE point of view.