I have a 12" PVC siphon pipe on one of my ponds
which is on a creek with a large watershed. I
haven't seen it work yet because the pond has not filled. The pipe was acquired at a local water co. at their cost. I know nothing about the company you refer to, but I'd guess that they work quit well. (just ask them if you don't beleive it). These systems are fairly common around my area in NE Texas. The pipe actually
goes through the dam (not over it) at the water level, and angles downward to a level where the
outlet is lower than the inlet. Emergency overflows are about a foot higher than the draw
level of the pipe. Ice could only affect the pipe at the water level down, and a freeze would have to be quite severe to create a problem.
