Criticize my Chicken Water Sketchup

chicken waterer

Kicking around ideas about a new design for providing water to my chickens. The idea is to make the watering device accessible from outside the enclosure. I've already got the nesting boxes and food bin accessible, but we still have to unhinge the gate and enter the run every time they need clean water.

Obviously, we'd prefer to keep them at pasture, but we live in an urban setting. They get to pasture in the yard for the afternoon if someone is home to keep an eye on them, but sometimes they stay in the run for days at a time. We've had problems with dogs killing them, so we have a "better safe than sorry" mindset right now.

The design I'm envisioning uses 3 components (see attached file)

A) a bucket with a lid outside the enclosure - this is where we add water
B) a pipe inside the enclosure - this is where the chickens obtain their water
C) a small pipe connecting the pipe and the bucket

The pipe inside the enclosure is aligned horizontally, with one quarter of the pipe cut away to make the water easily accessible for the chickens. We're planning to situate the pipe at a height where the chickens can drink comfortably, but high enough that they hopefully won't jump up there and foul the water too often.

The pipe and the bucket will be secured in place with wood fixtures attached to the enclosure itself. I'll use a laser level like this one to make sure it's installed so that the water level will be right when it's filled.

Thoughts I have:

1) the device will need an easily accessible drain at its lowest point to drain water out in case of hard freeze
2) there's still the possibility that the chickens will jump up and foul the water: need ideas about how to minimize this
3) the height of the pipe will be determined by the height of the chickens' necks - we'll test by filling the pipe with goodies and watching them fetch the goodies - try to find the optimum height by observing them - BUT - the height of the bucket is a variable I haven't quite figured out. Was thinking that it might be best to situate bucket where the water level is consistent with the amount of water in one of our most frequently used watering cans... thoughts?

Just looking for ideas and feedback before I spend an afternoon putting it all together... Thanks