Weep hole ideas for a wet system

So I'm using a wet catchment system to route rain from the roof of my house to my tanks.   I don't really like the idea of standing water in the pipes anytime it's not raining.   Mainly because I live in Montana and I don't want the pipes to become a solid frozen block of ice in the winter time (but still want to catch snow melt)

So I was thinking why can't I install a weep hole at a low point of the pipe somewhere.   Like what first flush devices use to slowly drain off the stored first flush water.  I understand it would be underground but thinking that shouldn't matter if I just put a small pocket of gravel around it.    But my concern is if debris will constantly be clogging the weep hole making the idea impractical.    I don't have a first flush device to know how effective these weep holes even are.   Do you have to constantly clean and adjust them?

Any other ideas to build a hybrid wet/dry catchment system?  One that's wet when you need it - but dry when you don't?

A couple of comments. Make sure the collection won't take in an occasional leaf, which could seal the hole. Im trying to envision what would happen if a leaf entered.  I suspect nothing would happen until the rain stopped. At that point the leaf (or debris) would flow straight to the weephole as its draining. During the next rain event it would be swept away. Something heavier, that cant be lifted to the top of the tank, would be persistent.

Also,  the water would have to enter the top of the tank. Pipe goes down to ground, then back up to top. This is probably obvious to you, as the water would drain out the weephole if it went in through the bottom.

I think its workable. Maybe add a clean out cap at the bottom weep area to give access if it does clog.

Don't put the weep hole on the bottom, put it up on the side a bit.  That way dirt, etc. won't plug it up as easily.
If it's underground then that part won't likely freeze, and if it does, it will be only partially full of water so it will have room to expand.

The gravel is a good idea, I'd also make it easy to access in case you ever do have to clean it out.  Again having the hole on the side will simplify maintenance since you could just poke a wire, etc. in from the side and wouldn't have to try digging it out from underneath.