I will try to find it locally so the pond build can go after this week vs. waiting on a shipment. How deep did you bury your plumbing? I presume if I want to try to run the pump all year, I should bury the plumbing at least 8-10". Or, maybe running the pump/waterfall all year in Chicago is not realistic.
We went as deep as was practical, but it's no where near 8" under ground. Maybe 4" tops. And we run our waterfall all winter long - have for four winters now with no problem whatsoever. Consider your waterfall carefully though to make sure you won't create areas where the ice will build up and re-direct water out of the pond. Our falls ice over completely, but the water is still flowing underneath.