Pond Boss Forums POND CONSTRUCTION Building a dam siphon system

I am interested in installing a system like this

http://www.ponddampiping.com/syphon1.html

I was worried about the water freezing in the 45 deg ell on the back side of the dam. Could you just use a 22 deg instead and put some kind of trash type guard on the end to keep the critters out? Or is there some other reason for the 45? Also I notice that this system does not have a collar on it in the core of the dame. Would it be beneficial to add one?

A collar would be a good addition but water would likely only be up high enough to cause problems for a very short period of time if the system is properly sized and installed. You could drill a small weep hole in the pipe between the 22.5deg and 45 deg so any water that remained could drain out.

Ryan,
My pond builder had told me the collar in a top drain system was to prevent leaks from the pipe loosening from the chuging action when the pond has completely filled to the top of the pipe and it cannot vent. Then it will "chug" and could loosen the pipe, allowing crayfish and water to move along the pipe and eventually cause a leak. We thought maybe this syphon system would prevent the chug. I agree that the collar would be a good addition either way.
If the 45 deg was slowly drained, wouldn't it defeat the purpose of having it as a trap? Unless there is some other reason for it that I am not aware of.

Thanks!

I have a 22 1/2 at the end of my two 12" siphons. I can't imagine why this would be a problem. To the best of my knowledge, they have never gone into siphon mode. The two 12" pipes are enough for even the heaviest rains we have had since the pond was built.