Villager farm getting clogged

Solution 1:

Here are two designs that I have used with success. Use the first one if you need the babies to come out the other end. They try to walk out of it but if they succeed they get a breath and get pushed back in. With this design, I always made sure the source block that pushes them into it was close so that it pushed them in with a bit of strength. If the source block is 7 blocks away, it doesn't push with as much force.

I use this design now. It pushes the villagers all the way back into the elevator where they can still breathe. It is a growing chamber of sorts because they can't exit until they are adults. If you get a bunch of babies at once, they stack up until they mature and exit.

As long as the elevator water are all source blocks, I have them swim ten water blocks before I put a sign so they can catch a breath. It looks like your system is only three blocks of climb so no air signs would be needed.

As to the baby villagers walking out of this design, passive designs always have that flaw. Babies like to hang out with the adults and some of them will mature in the breed chamber.

Here is a completely different village breeder style.

Here is the basic breeder cell:

The villagers are placed into the hole and bounce in the water. The water is held back on all sides by signs. When the villagers breed, the babies are pushed out the bottom to be caught and moved.

Here is a shot of a full build with breed cell and baby containment:

In this case, the babies are trapped until mature and then they are spit out into the void.

You can see the farmer with his farm in the image. He has a single hole with a shelf to throw the breeders food. He keeps them fed, they keep breeding.

Here is a mediafire download of that world built for the screenshots. It is named "Villager Breeder.zip" and it is 250KB.

This world also has a method to disable the village to stop/start breeding as desired.