I am relying on a creek running behind my dam to keep my water levels up this time of yr. I currently have a 20gpm 220V submersible but it is only pumping about half that due to what apparently is continued sludge getting in it despite the fact that it is pumping on clean water and I have cleaned the pump on a regular basis. I am wondering if I would be better off with a trash type of submersible or something of the like? I am using an 1.5 " pipe with 80 ft lift. My creek runs reliaable about 20GPM year round.