I'm trying to develop a way to design an efficient water delivery system for a possible impoundment on our farm without drilling a well or using a trash pump given how long it would take to fill. We have a pretty reliable creek in close proximity. So here's the question... If we were to install pvc piping from the creek (elevation 58') to a low "pool" in the impoundment (elevation 54') with an inline check valve... obviously the low "pool" would fill with water given gravity. The kicker is that the remainder of the impoundment would not be dug to an elevation of 54' and would in all reality be more like 62'-64' which is above the elevation of the creek itself. So... I guess the question is once the remainder of the impoundment fills to an elevation of maybe 55'-56' at the approximate elevation of the check valve, does the "static" pressure of the water inside the impoundment reach a high enough level that water will no longer gravity flow and keep filling the impoundment? Basically... do you think the check valve would shut with only 2'-4' of falling water pressure from the creek when there would be static water inside the impoundment resisting the incoming water? Below is a crude sketch of what I am referring to. Thoughts?