Running discussion on SP, page-21022

I’m no expert in pumps, but have installed 200ltr/min systems in basements, and the water flow via a 200mm pipe at only a couple of meter head had a significantly higher discharge rate to the point where it came out it the headwall of the culvert full velocity for 500mm before gravitating (streaming) down to base.

The picture posted by Mgt of the dewatering looks very inadequate given the huge volumes to be moved (in my baggy ass builders opinion) .....