I did a little exercise on this and its really simple to get interesting pushes of items in a water flow. This would work in brooks and rivers as well as the pressurized sources they behave like.
Pathfind from where the additional water enters to where it finds space. This should have some weighing towards straight lines instead of shortest path.
Along this path, create a vector that pushes objects with a force appropriate to the strength of the flow.
Now the tricky bit. When possible, create additional vectors with somewhat less pushing power to squares 45 degrees from the main vector. For each of these do the same, and each of those do the same, for a total of three iterations of additional 45 degree vectors whenever a vector enters a square of 7/7 water.
You get something like this:
Flowing from the bottom. Orange is the main flow, Green is the first branch, blue the second branch, and pink the third branch. I couldn't put too much work into arrowheads, but the visual effect is sufficient. This serves perfectly to push objects out of the flow when the stream widens and pull objects into the flow when its narrow. It creates stagnant areas on both inside and outside curves, and pulls objects back into the outflow. An object could exit and enter the main stream through here three times, flowing right out the top, or be pushed to the west bank to rest, or pulled into an eddy on the east bank.
For a half-hour idea, its quick, dirty, efficient, and realistic.
For drawing nice arrows I've just about resolved to stop ever trying unless I'm in a program like illustrator.
However you could have reduced the effort by
drawing just one nice arrow and then pasting copies onto a color adjustment layer for each iteration. With this many you might want to just keep an untouched single arrow off to the side and set up the 90 degree bend to do most of your pasting with.
And of course you could skip the color layer thing and just adjust the hue of a layer but that's less friendly to adding in things later.
I should probably just get myself an arrow vector I like and save it in photoshop though.
Anyway, this looks good for when you've got a single tile input and single tile output from a pool like that but if you've only got one input it's never going to spread out appropriately and (for 3 width exit) you'll get this strong flow line running next to two much weaker lanes.
In the case of a lake with a river running through it the flow should virtually cease a few tiles in, at least at the scale where you'd be pushing around gnomes or whatever in the water. I've been to a few swimming areas like that and there's really no current until right where the wide pool ends and the flow is all concentrated back into a narrow stream of water.
The semi-popular idea of mapping out the shape of the whole body of water and just assigning a flow direction to it seems like it would be necessary for dispersing currents and would have the benefit of also having application in getting large but shallow bodies of water to spread out quickly.
So will the new surgeon be able to fix cats?
I think there's not going to be any vet care like plasters and such for animals in the new version.
I read fix like spay/neuter.
In which case no, not yet.