Somebody please explain this to me, and either confirm or deny what a pump guy told me. I do not work with pumps much as most of my systems are on municipal water supplies so I admit ignorance on this. My clients have a shallow irrigation well with above ground Goulds centrifugal pump. The footvalve sits about 20 feet down in the well. During the winter the water level is only a couple feet above the footvalve, but in the summer, according to the client, the well fills up due to large scale irrigation of surrounding fields. I had to design a sprinkler system for them during the dry/winter season based on the water level being about 20 feet below the pump; therefore 20 feet of suction lift to add to the pressure loss calculations. A pump professional told me that when the well fills up, the pressure loss will decrease based on the higher water level. While I kind of get this, it doesn't quite make sense, because the pump intake is still 20 feet down and the pump has to pull the water up 20 feet even though the water level may be only a couple feet below the pump. How does this work? Please enlighten me Lawnsite veterans.