Sounds like a sump pit without a pump. They must have another method of getting rid of the water.
If you zoom in on the 2nd image you see 2 connections/pipes dumping into this "pit/pipe". The one on thr bottom of thr image does an S curve and it's end is in thr center of this image. The other end of that "pipe" is a floor drain in the basement utility room.
If jedi pours water in that drain it fills up to the top and eventually is slowly goes down and jedi sees water movement in the center of this pit/pipe. So that floor drain is connected to this pit/pipe.
The bigger pipe on the right (2nd image) no idea where the other end is at. However during heavy rain jedi does see a small trickle of water coming from that pipe and into the pit/pipe.
jedi has never seen the water go above that pipe. There is lots of mud/sedemit at the bottom. The very bottom and side walls are lined with brick.