I have a Rule "automated" pump
in a boat that collects a lot of rain water. It has an internal sensor that makes the pump
come on when the water level rises and keeps it running 20 seconds after the water level drops so it cycles less. This also makes it suck out more water before shutting off, but it still leave about an inch of water.
Another pump, The Whale SuperSub claims to get the water level down to 3/8" or something like that. I bought one, but haven't tried it yet.
The only way to prevent the water in the hose from coming back in is a check valve at the pump. The problem with this is that the water that remains in the hose will freeze, potentially causing it to burst, leading to a whole new set of problems.