Victorian water chamber

At the highest point in my village there is an old, windowless red brick building which is almost lost in a thicket of brambles. Acccording to my elderly neighbour it houses the rusting remains of a pump and large cast-iron cistern and was in fact the means by which the villagers had cold running water delivered to their houses by gravity. Apparently it was funded by the lord of the manor - how kind of him! The water was pumped up from the river some 400 yards downhill in the valley.

As is my way, being an angler, I poke around the bankside undergrowth where most, if not all, sane people keep well away. Thus, to my great delight this morning, I came across what can only be the remains of the screw operated iron door which admitted river water into a large sump or chamber. It's my guess that the chamber (which you can see canted over to one side) would be filled and left for perhaps a day for the silt to settle to the bottom and then the pump awould be activated to suck up the "clean" water. The chamber would then be flushed through and refilled.