[AllanJ]

The sump pump pit is put near the foundation wall (often in a corner) because that is where the perimeter drain pipes run or should run.

Not all houses have perimeter drain pipes. If yours doesn't and also you have basement flooding problems, you will have to install such pipes which means digging up all around the foundation down to its footings, your choice of inside or outside.

Retrofitting the house with perimeter drain pipes is usually easier on the inside even though you have to crack up the concrete basement floor.

The first thing to do about basement flooding is to eliminate water pooling up around the foundation outside, doing whatever you have to do including regrading the land.