Candidly, can a duck family survive going over a waterfall?
At a nature park I was watching a family of eight ducklings and a mother eating along the banks of a lake before a couple of the ducklings got caught in a current and fell down a concrete slope that drains into a stream from the lake. Picture a stepped waterslide, essentially. The remaining ducklings followed, then the mother flew down to the stream where some of the ducklings had ended up. Eventually the remaining ducklings swam down the rest of the 'waterfall'. At this point the last I saw of any of them was the mother briefly flying back up to the halfway point and calling, then flying back down, and then her swimming near the start of the stream with one duckling in tow. The waterfall itself a relatively gentle slope and the stream calms down quickly and isn't especially violent to begin with.
I walked a trail along the stream but saw and heard nothing (it's quite a delay to be able to get down to it). About 30 minutes later I returned to the lake and saw two ducklings calling out along the middle of the same bank the family was feeding at, but could find nothing else. A few hours after this I returned a final time and saw a mother duck with five ducklings huddled together on the same bank on the outside corner of a lookout platform with an adult male floating in place nearby. I then walked the stream one last time but again saw and heard nothing.
A few questions: what are the odds the two ducklings/mother and five ducklings I saw are the same family? I initially saw the family swimming and feeding a decent ways past where this final encountered group was resting, but still the same overall bank. This lake is about 250 hectares and fairly unbroken. If it is the same family, what are the odds the three missing ducklings died or went missing? I noticed no overt injuries and heard no calls of distress during and after the initial incident. If they went missing, is there any chance the mother continues attempting to look for them considering she gathered five and led them back to the lake? The only way to do this with flightless ducklings would be a complicated trek up switchback trails or up steep forest floor hills, bordering on cliffs immediately along the start of the stream, although this artificial fall is only about 25 feet, I'd wager. If they're separate families and this other one just kept on keeping on in the stream, I can't speak to where it eventually leads, but is there any chance they'll just establish new nesting grounds?
I reached out to park services when I witnessed the incident, but this is a holiday so I was redirected to a 24/7 general city line. The worker who took the call reached out to a couple of relevant services according to them, as well as notifying the park management/rangers/maintenance working today who noted it down and told the line worker they would keep an eye on the situation as permits when servicing the park. This is realistically all I can do without reckless interference as any specific wildlife outfits are closed today (I'm honestly not sure what immediately local presence is like, either). I should also say I've got no observational history with this lake concerning duckling activity and hadn't been there in weeks so I can't speak to how crowded it is right now. It was very quiet on birds overall today, though. A few scattered mallards and wigeons.
I'm asking this earnestly in a place where I can be more assured people in the know might be able to speak generally on the situation given the details. To be frank I made a thread for outreach at a local level but it went over like a lead balloon and the implied consensus from my read of it is basically that I'm being a histrionic idiot. Which if I am, good, but I'd rather hear that from people who know ducks. Don't be afraid to be frank with me.