On my regular route, as I was about to cross the bridge over the lock that brings me back towards work, a woman rushed passed carrying a bucket.
She said something about possibly having to catch "it" to another woman who was standing near the canal. I jokingly asked if she was catching ducks, and she said, "no, cygnets", and explained that two of the new resident cygnets had gone over the waterfall and that a couple of rival swans were trying to kill them.
She said that we'd have to usher them into the lock, close the doors to keep them in and the others out, while letting the water rise until we could open the doors on the other side and reunite them with the rest of their family.
In the meantime, she said we might need some rocks or something to scare off the aggressive adults. I helped her gather some pebbles and we shouted and shooed them away every time they started to close in on the one desperate little cygnet. Having already been bitten, it was too afraid to swim to the lock and was trying to swim up from the bottom of the falls.
We finally managed to scare off the swans (with the very large mother's help) and the little one was able to swim freely into the lock. We closed the door on the two of them, and they knew (because this isn't the first time residents of the lock-side building have rescued them this way) to swim to the other end and wait for the water to rise.
The father and third cygnet came to the top to await the return of the lost ones. When the water got high enough they were calling to each other through the gates of the lock; the babies started getting excited and tried to jump over the gate. But we finally opened it enough for them to squeeze through and they happily joined their sibling and father and swam off to (hopefully) safer waters.
Here is a link to see what the lock and mill (now converted into apartments) looks like: http://www.photoeyes.biz/general/coxeslock.htm
Here are a few shots of the action (sorry if it's a bit blurry or difficult to see, I was throwing rocks and pushing gates open at the same time as I was snapping shots). I will add the video later.
Cygnet taking a breather before continuing his attempt to swim against the current (you can just see him peaking out from the wall on the far left side)
Second cygnet waiting for his brother to join him in the lock
The two of them getting soaked while waiting for the water to rise
The father heads over (ready for action) to greet his babies with the third in tow
As the water rises, they are able to see each other through the gate
Together again!